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00:19 Feb-13-2001
Xu Dianguo
Re: NDT failure analysis for wires/ cables : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: NonDestructive Testing (NDT) of Ropes
: TS Golosinski

: The paper reviews winder rope inspection procedures at the Non Destructive Testing (NDT) Unit of Western Australian School of Mines (WASM) and outlines measures taken to adopt the world's best practice. The measures include acquisition of a new type of rope tester, adoption of comprehensive rope rejection criteria, adoption of a standard rope inspection procedure and formal training of the wire rope inspectors.
: BACKGROUND

: In the mid- to late-1980s several catastrophic failures of winder ropes took place in Canadian mines. All failed ropes were periodically inspected with magnetic or electro-magnetic NDT instruments during service, some just days before the failure. Documented in detail by Geller et al (1989) these failures lead to an in-depth evaluation of the NDT rope inspection techniques in a study conducted jointly by the US Bureau of Mines and CANMET, a Canadian Federal Government research organisation. An initial stage of this study concentrated on review of past rope inspection practices and led the chief investigators to conclude that; "no more than some 50 per cent of the NDT estimates were within ± four per cent accuracy range' and that 'in a number of cases the rope breaking strength seemed to have diminished well beyond the amount permitted by the relevant provincial regulations' (Geller and Udd, 1988).
: While the study has proven that introduction and use of NDT techniques for rope testing has greatly increased safety of winding , it identified a number of instances where the inspection results were outside the acceptable error range. Unreliability of many inspections was attributed to human related problems (Geller and Udd, 1988) and most notably from:

: 1. lack of adequate, uniform and generally available operator training procedures;

: 2. lack of adequate and uniform instrument and operator certification procedures; and

: 3. difficulties in obtaining reliable LBS (Loss of Breaking Strength) estimates based on measured LF (Local Fault)and LMA (Loss of Magnetic Area) data.

: Other findings of the study indicated that rope testers providing both LMA and LF data allow for more accurate estimates of LBS than the single function instruments and that certain rope types, constructions and defects are particularly difficult to measure using the NDT techniques.
: A follow-up study by CANMET compared accuracy of the rope inspections conducted with several types and models of NDT rope testers. Ropes of various constructions and diameters were used in this study. It resulted in development of detailed recommendations on selection, design and operation of the NDT testers.
: In Western Australia NDT inspections of winder ropes are conducted by the NDT Unit of WASM, a joint venture between the school and several mining companies. In addition to rope inspections the Unit also inspects rope attachments and various winder gear, and conducts a range of NDT tests using ultrasonic, penetrant, magnetic particles and other methods. Aware of the CANMET studies referred to above and driven by a desire to provide the industry with the highest quality service the management of the Unit launched a comprehensive review of rope inspection practice in place. As a result several aspects of the inspection were identified for possible upgrade. These were:

: 1. upgrade the rope testing equipment;

: 2. develop and adopt accurate rope rejection criteria;

: 3. adopt a standard rope inspection procedure; and

: 4. provide formal training for the inspectors.

: NDT APPARATUS

: Assessment of the condition of two rope testers owned by the NDT Unit indicated the need for an upgrade. A world wide search for a new tester was launched to facilitate this. At the same time feasibility and conditions of refurbishment of the testers at hand were investigated. This was found to be non competitive on commercial and technical grounds. The search for a new rope tester included identification of commercial suppliers and comparison of the relevant specifications. The base for comparisons, apart from technical specifications, were the desirable instrument characteristics defined in the CANMET study (Geller et al, 1990) as follows:

: 1. The instrument should be designed for adding, if so desired, electronic means to the paper chart records such as, for example, a frequency modulated (FM)tape recorder for recording, and for faithful playback of the following signals: (a) LMA, (b) LF. © test speed, (d) length, and (e) direction of measurements. The signal to noise ratio of the recording and play back process should be kept as high as possible in order that: (a) the added noise be less than 0.1 per cent of the LMA channel, and (b) the LF signal induced by a rope defect not be lost among electronic noise.

: 2. All control settings, such as zero and gain for both the LMA and LF signals should be equipped with a dial both readable, as wall as resetable, to within one-tenth of one per cent, so as to be able to exactly reconstruct the levels set during the original rope tests.
: 3. The electronic and magnetic characteristics of the instrument must be stable timewise (at least between factory calibration) and temperaturewise (between 20°C and +40°C for the sensor head and between +5°C and 35°C for the electronics)

: 4. The speed compensation must ensure that the amplitude of a discontinuity will remain constant regardless of the rope speed.

: 5. Both LMA and LF measurements should be independent of rope speeds in the approximate range of zero to three m/s.

: 6. The instrument should produce charts with both LMA and LF traces.

: 7. The instrument's LMA, LF, distance and direction signals should be easily accessible for further recording and processing.

: 8. The range of the LMA measurements should extend to at least +5 per cent and -20 per cent in case of the largest rope size measurable by the instrument.

: 9. The chart paper advance should be proportional to the measured rope length.

: 10. The instrument should be capable of both the absolute and the relative metallic area measurements.

: 11. It should be possible to locate the sensor head at least 8 m from the control unit.

: 12. Influence of outside electromagnetic fields upon the output signals should be within acceptable limits.

: 13. The auxiliary magnetic field induced by the sensor head should be minimised.

: 14. The instrument should be easily portable, be capable of self-contained operation, its batteries should last for at least six hours of continuous operation, it should be sturdy and resistant to environmental effects (splash proof),it should have mounted on it, in an appropriate location, condensed instrument operating instructions and chart calibration procedures.

: 15. A warning signal must appear whenever the instrument's electronic circuit reaches saturation, ie whenever the data produced have been rendered invalid.

: 16. Instrument stability should be within one per cent LMA per hour (ie a ten per cent LMA reading should not drop to less than nine percent within an hour).

: In total six rope tester manufacturers were identified with a record of worldwide sales and service, two in Canada and one each in the USA, Germany, Poland and South Africa. The specifications and characteristics of the first five testers were made available to the Unit and analysed in detail. While each of the manufacturers offers several tester models, the analysis was limited to the models best meeting the NDT Unit application criteria which were testing of stranded winder ropes with diameter ranging between 15 mm and 60 mm. A summary of the findings of this analysis is presented in Table 1. Apart from technical specifications and those defined by CANMET additional conditions were included in the selection dealing with commercial terms, time and terms of delivery, and service support.

: The bid review led to the decision to purchase the rope tester manufactured by Meraster of Poland, model MD-120, with the measuring head model GP2. In addition to scoring best in the comparison based on the CANMET criteria, and meeting other conditions, the tester allows for:

: 1. recording the measured data on a PC card for easy computer processing;

: 2. instantaneous recording of the LF signal from two measuring coils, each of different diameter, what in turn allows for accurate quantification of rope damage; and

: 3. automatic integration of rope damage over a selected rope length.

: All three are identified on the sample strip chart recording shown in Figure 1. Delivery of the MD - 120 tester wad taken in October 1994. Since then it has been used as the main rope tester with the two older instruments used as back-up.

: ROPE REJECTION CRITERIA

: The purpose of rope inspections is to define the rope condition relative to that considered safe for the intended use. Rope condition is most commonly defined in terms of the loss of its breaking strength (LBS) from that of the new rope. The maximum permissible loss of LBS is then defined for a specific rope application and the measured LBS is compared against that maximum. Alternatively the safety factor for a specific rope application is defined and the rope is discarded when its remaining breaking strength is insufficient to secure this factor.

: Neither the Western Australia Mines Regulations Act and Regulations 1976 nor the Australian Standards retail the winding rope wear and rejection criteria in a form which could be used in conjunction with the NDT inspections. The Regulations state that 'a rope … shall forthwith be withdrawn from use when …( c ) Non-destructive examination of the rope using approved non-destructive testing equipment shows that continued use of the rope is not consistent with safe operation of the hoisting or haulage operation'. This leaves the responsibility for determination of the most appropriate rope rejection criteria with the NDT Unit. In the past the Unit used a criterion based on the maximum permissible loss of magnetic area of a rope (LMA signal) complemented by the maximum permissible number of broken wires (LF signal) and expressed as a loss of LBS. As a general rule the clients were recommended to discard a rope if its.

: Dr Brandt Magnograph Rotescograph LMA 250 Meraster
: Magnetisation

: Instrument Type

:
: Sensors

: Head mass, kg

: Console mass, kg
: Electrical power
: Rope diameter, mm
: Rope speed, m/s
: LMA averaging length, mm
: Computer interface
: Software
: Inspector training
: Availability
: Compliance with
: CANMET specifications rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 35

: 27

: batteries/AC
: 8 to 64

: 0.3 to 1.5
: n/a

: yes

: included
: 1 day

: 20 weeks
: meets most rare earth
: permanent m
: dual function
: LMA/LF

: Hall

: 45

: 35

: batteries/AC
: 10 to 64

: up to 3
: 200

: yes

: n/a
: n/a

: 1995 or after
: meets many ferrite
: permanent m
: dual function
: LMA/LF

: coils

: 40

: 20

: AC only
: 10 to 64

: up to 3
: 200

: no

: n/a
: n/a

: 1995 or after
: meets some rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 32

: 22

: batteries/AC
: 10 to 64

: 0* to 3
: 75

: no

: n/a
: n/a

: 6 weeks
: meets most rare earth
: permanent m
: four functions
: LMA/LF/LF/INTEGR
: Hall + two LF coil sets
: 42 (large) 7 (small)
: 12

: batteries/AC
: 10 to 60

:0.05 to 10
: 100

: yes (+4MB internal)
: available
: 1 week

: 12 weeks
: meets all
: exceeds many
: * specified by the manufacturer.

: LBS estimate amounted to ten percent or more of the breaking strength. While this criterion meets the requirements of the Regulations it leaves a margin for error in view of difficulties with relating the measured value of LMA to the actual LBS of a rope (Fuchs and Schroeder, 1992). The variety of winding rope constructions used in Western Australia contributes to the problem.
: It is important for accurate assessment of rope condition that all forms of wear are taken into consideration (Poffenroth, 1989). While the indications of a NDT rope tester allow in most cases for quantification of rope wear, other forms of wear not detectable with the tester must be assessed as well. To research the best practice in this area a world-wide literature search for related information was undertaken. It yielded a large volume of data including several sets of comprehensive rope rejection criteria. Comparison of these led to the decision to adopt the set developed recently by the Angle American Corporation of South Africa (Kuun et al, 1993) These criteria are listed in Appendix 1.
: Accuracy of rope condition assessment was significantly enhanced by the availability of two LF signals from two separate coils of the MD-120 tester. The signals allow for introduction of corrections reflecting the position and size of rope faults. As a result accurate quantification of rope damage is possible (Golosinski, 1995).

: ROPE INSPECTION STANDARD

: There is no Australian Standard which details the procedure for NDT testing and inspections of ropes. The procedure followed by the Unit was arrived at in an evolutionary manner by analysis of various relations observed during inspections. Advice of tester manufacturers and service staff was also solicited from time to time and contacts were made with the similar laboratories nationwide.
: In 1993 the ASTM (American Societyfor Testing of Materials) adopted the standard E 1571-93 which defines the Standard Practice For Electromagnetic Examination For Ferromagnetic Steel Wire Rope. The standard was developed by the ASTM committee E-7: Non-Destructive Testing. Its development and approval was a direct result of USBM involvement in the research project conducted jointly with CANMET and referred to earlier.
: The ASTM standard details the scope and sequence of activities which need to be included in the rope inspection, describes in detail the inspection procedure, imposes data processing and reporting requirements, and details the tester calibration procedure. In general the standard, if followed, reduces the risk of human errors and assures that the accuracy of rope condition assessment is as reliable as feasible. In absence of the corresponding Australian standards the ASTM standard on electromagnetic examination of ropes was adopted by the NDT Unit of WASM for conducting of all rope inspections.

: TRAINING OF INSPECTORS

: The NDT Unit inspectors have been certified by NATA (National Association of Testing Authorities) as qualified to conduct rope inspections. While this recognises their rope testing skills, the qualifications were acquired by hands-on inspection experience, self-education and contact with the tester manufacturer and service is very limited. Considering that the CANMET study identified lack of formal inspector training as one of the main factors contributing to unreliability of some inspections, an effort has been made to identify a suitable training program overseas or to develop one in-house.
: A formal, structured training program for rope inspectors is currently being established by Anglo American Corporation in South Africa (Kuun et al, 1993). Inquiries have been made with that company regarding feasibility and conditions of training NDT Unit inspectors in South Africa. Somewhat similar programs have been established in Poland and Germany. All these programs meet the requirements defined in the CANMET study. Review of feasibility and conditions of having inspectors trained overseas lead to an agreement with the Rope Transport Laboratory of the University of Mining and Metallurgy in Cracow, Poland, for provision of a one-week course in NDT rope inspection techniques. This laboratory has a long history of involvement with rope inspections dating back over 30 years and was instrumental in development of the MD-120 tester discussed above.
: Two NDT Unit staff took part in this training which was timed to coincide with the commissioning of the MD-120 tester acquired by WASM. This allowed the new tester to be used for practicals during the training sessions and provided staff with hands-on familiarity with it . It also eliminated potential tester start-up problems. The scope of this custom-designed training program included rope constructions and properties, rope wear patterns and their quantification, basics of NDT inspections of ropes, familiarisation with the MD-120 instrument and its calibration, and procedures for definition and quantification of rope damage.

: CONCLUSIONS

: In an effort to upgrade reliability of winder rope inspections the NDT Unit of WASM has:
: 1. upgraded the testing apparatus;
: 2. defined and adopted suitable rope rejection criteria;
: 3. conducts the inspections in accordance with the relevant ASTM standard; and
: 4. trained the inspectors in the rope NDT techniques.
: These measures guarantee that inspection services supplied by the WASM NDT Unit follow the world's best practice and that the Unit provides its clients with reliable assessment of rope condition.

: APPENDIX 1
: Rope rejection criteria adapted from Kunn et al, 1993.


: BROKEN WIRES
: Described as loss of steel area of rope

: In one lay length:
: symmetric (LT 2/3 in three adjacent strands)
: asymmetric (MT 2/3 in three adjacent strands)
: In five lay lengths
: symmetric
: asymmetric

: LOSS OF DIAMETER
: Percentage of the larger of nominal or mid-rope
: diameter of new rope

: Wear and plastic deformation
: uniform around the rope
: mainly on one side of the rope
: Wear only
: uniform around the rope
: mainly on one side of the rope

: Any other causes
: increase or decrease in diameter

: CORROSION
: Identified by EM testing or visual inspection of rope

: Internal: indicated EM loss in area x multiplication factor established for
: the instrument
: External: pronounced pitting, slack wires, fractures in gussets

: DISTORTION
: Percentage of rope diameter established as for loss of diameter

: Waviness: setback of rope wave valley from its crest expressed as a per
: cent rope diameter.
: Angular bends: measured over two lay lengths
: Kinks: any kink is reason for discard

: FIBRE CORE
: Failure of core is reason for discard

: CHANGE IN LAY LENGTH
: General variation as percentage of nominal:
: increase
: decrease
: Local variation
: over six strand: percentage of the average of adjacent values

: HEAT DAMAGE
: Discard at any sign of heat damage such as:
: arcing, pits, discolouration, etc.

: MECHANICAL PROPERTIES
: Percentage reduction in values for the new rope

: Loss in breaking strength
: Loss in total strain energy to failure

: SHORT ROPE

: Less than three full turns on drum after cutting of front end samples, pulling in back end, or removal of defective ends of rope

: COMBINED EFFECTS

: Sum of individual fractions of the specified values, particularly of broken wires and loss of diameter, not to exceed value of 1.0

: RATE OF IN CREASE IN DETERIORATION

: The rope should be discarded if the maximum allowable levels of deterioration are expected before the next examination
: CRITERION
: (%)


:
: 8
: 5

: 16
: 10

:
: 10
: 7

: 7
: 7

:
: 8


:
: 7

: any


:
: 25

: 6

:
: 100
: 30

: 12


:
: 10
: 50


: REFERENCES

: ASTM standard E 1571-93. Standard Practice for Electromagnetic Examination for Ferromagnetic Steel Wire Rope.
: Fuchs, D and Schroeder, R, 1992. The safe load of winding ropes in large Koepe hoists - an assessment based on non destructive testing, OIPEEC Bulletin, No 63, (Reading Rope Research: Reading, UK)
: Geller, L B and Udd, J E, 1988. Comparative evaluation of mine-shaft wire-rope NDT instruments. Report MRL 88-78 (TR) CANMET: Energy, Mines and Resources Canada
: Geller, LB, Udd, J E, Blanchard, R and Daniel, K E, 1989. About electromagnetic testing in New Brunswick mines and related data. Report MRL 89-40(TR) CANMET: Energy, Mines and Resources Canada.
: Geller, L B, Rousseau, G and Poffenroth, D, 1990 Canada/NB MDA project on mine-shaft rope testing: stranded ropes with artificial defects. Report MRL 90-015 (TR) CANMET: Energy, Mines and Resources Canada.
: Golosinski, T S, 1995. Assessment of winder rope condition, in Proceedings Australasian Materials Conference, Perth, October
: Kuun, T C, Wainwright, E J, Dohm, A A R and van der Walt, W P, 1993 Condition assessment of winding ropes, in Proceedings Mine Hoisting 93 p 6.2.1 -6 (The Institution of Mining Electrical and Mining Mechanical Engineers of UK).
: Poffenroth, D N, 1989. Procedures and results of electromagnetic testing of mine hoist ropes using the LMA - TEST instruments, in Proceedings Wire Rope Discard Criteria pp 17.1 - 21 (Swiss Federal Institute of Technology (ETH).
: WA Mines Regulation Act 1946 and Regulations 1976. (WA Government Printer, 1991).
: Wavlets Analysis combined with NN




 
00:20 Feb-13-2001
Xu Dianguo
Re: NDT failure analysis for wires/ cables : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: NonDestructive Testing (NDT) of Ropes
: TS Golosinski

: The paper reviews winder rope inspection procedures at the Non Destructive Testing (NDT) Unit of Western Australian School of Mines (WASM) and outlines measures taken to adopt the world's best practice. The measures include acquisition of a new type of rope tester, adoption of comprehensive rope rejection criteria, adoption of a standard rope inspection procedure and formal training of the wire rope inspectors.
: BACKGROUND

: In the mid- to late-1980s several catastrophic failures of winder ropes took place in Canadian mines. All failed ropes were periodically inspected with magnetic or electro-magnetic NDT instruments during service, some just days before the failure. Documented in detail by Geller et al (1989) these failures lead to an in-depth evaluation of the NDT rope inspection techniques in a study conducted jointly by the US Bureau of Mines and CANMET, a Canadian Federal Government research organisation. An initial stage of this study concentrated on review of past rope inspection practices and led the chief investigators to conclude that; "no more than some 50 per cent of the NDT estimates were within ± four per cent accuracy range' and that 'in a number of cases the rope breaking strength seemed to have diminished well beyond the amount permitted by the relevant provincial regulations' (Geller and Udd, 1988).
: While the study has proven that introduction and use of NDT techniques for rope testing has greatly increased safety of winding , it identified a number of instances where the inspection results were outside the acceptable error range. Unreliability of many inspections was attributed to human related problems (Geller and Udd, 1988) and most notably from:

: 1. lack of adequate, uniform and generally available operator training procedures;

: 2. lack of adequate and uniform instrument and operator certification procedures; and

: 3. difficulties in obtaining reliable LBS (Loss of Breaking Strength) estimates based on measured LF (Local Fault)and LMA (Loss of Magnetic Area) data.

: Other findings of the study indicated that rope testers providing both LMA and LF data allow for more accurate estimates of LBS than the single function instruments and that certain rope types, constructions and defects are particularly difficult to measure using the NDT techniques.
: A follow-up study by CANMET compared accuracy of the rope inspections conducted with several types and models of NDT rope testers. Ropes of various constructions and diameters were used in this study. It resulted in development of detailed recommendations on selection, design and operation of the NDT testers.
: In Western Australia NDT inspections of winder ropes are conducted by the NDT Unit of WASM, a joint venture between the school and several mining companies. In addition to rope inspections the Unit also inspects rope attachments and various winder gear, and conducts a range of NDT tests using ultrasonic, penetrant, magnetic particles and other methods. Aware of the CANMET studies referred to above and driven by a desire to provide the industry with the highest quality service the management of the Unit launched a comprehensive review of rope inspection practice in place. As a result several aspects of the inspection were identified for possible upgrade. These were:

: 1. upgrade the rope testing equipment;

: 2. develop and adopt accurate rope rejection criteria;

: 3. adopt a standard rope inspection procedure; and

: 4. provide formal training for the inspectors.

: NDT APPARATUS

: Assessment of the condition of two rope testers owned by the NDT Unit indicated the need for an upgrade. A world wide search for a new tester was launched to facilitate this. At the same time feasibility and conditions of refurbishment of the testers at hand were investigated. This was found to be non competitive on commercial and technical grounds. The search for a new rope tester included identification of commercial suppliers and comparison of the relevant specifications. The base for comparisons, apart from technical specifications, were the desirable instrument characteristics defined in the CANMET study (Geller et al, 1990) as follows:

: 1. The instrument should be designed for adding, if so desired, electronic means to the paper chart records such as, for example, a frequency modulated (FM)tape recorder for recording, and for faithful playback of the following signals: (a) LMA, (b) LF. © test speed, (d) length, and (e) direction of measurements. The signal to noise ratio of the recording and play back process should be kept as high as possible in order that: (a) the added noise be less than 0.1 per cent of the LMA channel, and (b) the LF signal induced by a rope defect not be lost among electronic noise.

: 2. All control settings, such as zero and gain for both the LMA and LF signals should be equipped with a dial both readable, as wall as resetable, to within one-tenth of one per cent, so as to be able to exactly reconstruct the levels set during the original rope tests.
: 3. The electronic and magnetic characteristics of the instrument must be stable timewise (at least between factory calibration) and temperaturewise (between 20°C and +40°C for the sensor head and between +5°C and 35°C for the electronics)

: 4. The speed compensation must ensure that the amplitude of a discontinuity will remain constant regardless of the rope speed.

: 5. Both LMA and LF measurements should be independent of rope speeds in the approximate range of zero to three m/s.

: 6. The instrument should produce charts with both LMA and LF traces.

: 7. The instrument's LMA, LF, distance and direction signals should be easily accessible for further recording and processing.

: 8. The range of the LMA measurements should extend to at least +5 per cent and -20 per cent in case of the largest rope size measurable by the instrument.

: 9. The chart paper advance should be proportional to the measured rope length.

: 10. The instrument should be capable of both the absolute and the relative metallic area measurements.

: 11. It should be possible to locate the sensor head at least 8 m from the control unit.

: 12. Influence of outside electromagnetic fields upon the output signals should be within acceptable limits.

: 13. The auxiliary magnetic field induced by the sensor head should be minimised.

: 14. The instrument should be easily portable, be capable of self-contained operation, its batteries should last for at least six hours of continuous operation, it should be sturdy and resistant to environmental effects (splash proof),it should have mounted on it, in an appropriate location, condensed instrument operating instructions and chart calibration procedures.

: 15. A warning signal must appear whenever the instrument's electronic circuit reaches saturation, ie whenever the data produced have been rendered invalid.

: 16. Instrument stability should be within one per cent LMA per hour (ie a ten per cent LMA reading should not drop to less than nine percent within an hour).

: In total six rope tester manufacturers were identified with a record of worldwide sales and service, two in Canada and one each in the USA, Germany, Poland and South Africa. The specifications and characteristics of the first five testers were made available to the Unit and analysed in detail. While each of the manufacturers offers several tester models, the analysis was limited to the models best meeting the NDT Unit application criteria which were testing of stranded winder ropes with diameter ranging between 15 mm and 60 mm. A summary of the findings of this analysis is presented in Table 1. Apart from technical specifications and those defined by CANMET additional conditions were included in the selection dealing with commercial terms, time and terms of delivery, and service support.

: The bid review led to the decision to purchase the rope tester manufactured by Meraster of Poland, model MD-120, with the measuring head model GP2. In addition to scoring best in the comparison based on the CANMET criteria, and meeting other conditions, the tester allows for:

: 1. recording the measured data on a PC card for easy computer processing;

: 2. instantaneous recording of the LF signal from two measuring coils, each of different diameter, what in turn allows for accurate quantification of rope damage; and

: 3. automatic integration of rope damage over a selected rope length.

: All three are identified on the sample strip chart recording shown in Figure 1. Delivery of the MD - 120 tester wad taken in October 1994. Since then it has been used as the main rope tester with the two older instruments used as back-up.

: ROPE REJECTION CRITERIA

: The purpose of rope inspections is to define the rope condition relative to that considered safe for the intended use. Rope condition is most commonly defined in terms of the loss of its breaking strength (LBS) from that of the new rope. The maximum permissible loss of LBS is then defined for a specific rope application and the measured LBS is compared against that maximum. Alternatively the safety factor for a specific rope application is defined and the rope is discarded when its remaining breaking strength is insufficient to secure this factor.

: Neither the Western Australia Mines Regulations Act and Regulations 1976 nor the Australian Standards retail the winding rope wear and rejection criteria in a form which could be used in conjunction with the NDT inspections. The Regulations state that 'a rope … shall forthwith be withdrawn from use when …( c ) Non-destructive examination of the rope using approved non-destructive testing equipment shows that continued use of the rope is not consistent with safe operation of the hoisting or haulage operation'. This leaves the responsibility for determination of the most appropriate rope rejection criteria with the NDT Unit. In the past the Unit used a criterion based on the maximum permissible loss of magnetic area of a rope (LMA signal) complemented by the maximum permissible number of broken wires (LF signal) and expressed as a loss of LBS. As a general rule the clients were recommended to discard a rope if its.

: Dr Brandt Magnograph Rotescograph LMA 250 Meraster
: Magnetisation

: Instrument Type

:
: Sensors

: Head mass, kg

: Console mass, kg
: Electrical power
: Rope diameter, mm
: Rope speed, m/s
: LMA averaging length, mm
: Computer interface
: Software
: Inspector training
: Availability
: Compliance with
: CANMET specifications rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 35

: 27

: batteries/AC
: 8 to 64

: 0.3 to 1.5
: n/a

: yes

: included
: 1 day

: 20 weeks
: meets most rare earth
: permanent m
: dual function
: LMA/LF

: Hall

: 45

: 35

: batteries/AC
: 10 to 64

: up to 3
: 200

: yes

: n/a
: n/a

: 1995 or after
: meets many ferrite
: permanent m
: dual function
: LMA/LF

: coils

: 40

: 20

: AC only
: 10 to 64

: up to 3
: 200

: no

: n/a
: n/a

: 1995 or after
: meets some rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 32

: 22

: batteries/AC
: 10 to 64

: 0* to 3
: 75

: no

: n/a
: n/a

: 6 weeks
: meets most rare earth
: permanent m
: four functions
: LMA/LF/LF/INTEGR
: Hall + two LF coil sets
: 42 (large) 7 (small)
: 12

: batteries/AC
: 10 to 60

:0.05 to 10
: 100

: yes (+4MB internal)
: available
: 1 week

: 12 weeks
: meets all
: exceeds many
: * specified by the manufacturer.

: LBS estimate amounted to ten percent or more of the breaking strength. While this criterion meets the requirements of the Regulations it leaves a margin for error in view of difficulties with relating the measured value of LMA to the actual LBS of a rope (Fuchs and Schroeder, 1992). The variety of winding rope constructions used in Western Australia contributes to the problem.
: It is important for accurate assessment of rope condition that all forms of wear are taken into consideration (Poffenroth, 1989). While the indications of a NDT rope tester allow in most cases for quantification of rope wear, other forms of wear not detectable with the tester must be assessed as well. To research the best practice in this area a world-wide literature search for related information was undertaken. It yielded a large volume of data including several sets of comprehensive rope rejection criteria. Comparison of these led to the decision to adopt the set developed recently by the Angle American Corporation of South Africa (Kuun et al, 1993) These criteria are listed in Appendix 1.
: Accuracy of rope condition assessment was significantly enhanced by the availability of two LF signals from two separate coils of the MD-120 tester. The signals allow for introduction of corrections reflecting the position and size of rope faults. As a result accurate quantification of rope damage is possible (Golosinski, 1995).

: ROPE INSPECTION STANDARD

: There is no Australian Standard which details the procedure for NDT testing and inspections of ropes. The procedure followed by the Unit was arrived at in an evolutionary manner by analysis of various relations observed during inspections. Advice of tester manufacturers and service staff was also solicited from time to time and contacts were made with the similar laboratories nationwide.
: In 1993 the ASTM (American Societyfor Testing of Materials) adopted the standard E 1571-93 which defines the Standard Practice For Electromagnetic Examination For Ferromagnetic Steel Wire Rope. The standard was developed by the ASTM committee E-7: Non-Destructive Testing. Its development and approval was a direct result of USBM involvement in the research project conducted jointly with CANMET and referred to earlier.
: The ASTM standard details the scope and sequence of activities which need to be included in the rope inspection, describes in detail the inspection procedure, imposes data processing and reporting requirements, and details the tester calibration procedure. In general the standard, if followed, reduces the risk of human errors and assures that the accuracy of rope condition assessment is as reliable as feasible. In absence of the corresponding Australian standards the ASTM standard on electromagnetic examination of ropes was adopted by the NDT Unit of WASM for conducting of all rope inspections.

: TRAINING OF INSPECTORS

: The NDT Unit inspectors have been certified by NATA (National Association of Testing Authorities) as qualified to conduct rope inspections. While this recognises their rope testing skills, the qualifications were acquired by hands-on inspection experience, self-education and contact with the tester manufacturer and service is very limited. Considering that the CANMET study identified lack of formal inspector training as one of the main factors contributing to unreliability of some inspections, an effort has been made to identify a suitable training program overseas or to develop one in-house.
: A formal, structured training program for rope inspectors is currently being established by Anglo American Corporation in South Africa (Kuun et al, 1993). Inquiries have been made with that company regarding feasibility and conditions of training NDT Unit inspectors in South Africa. Somewhat similar programs have been established in Poland and Germany. All these programs meet the requirements defined in the CANMET study. Review of feasibility and conditions of having inspectors trained overseas lead to an agreement with the Rope Transport Laboratory of the University of Mining and Metallurgy in Cracow, Poland, for provision of a one-week course in NDT rope inspection techniques. This laboratory has a long history of involvement with rope inspections dating back over 30 years and was instrumental in development of the MD-120 tester discussed above.
: Two NDT Unit staff took part in this training which was timed to coincide with the commissioning of the MD-120 tester acquired by WASM. This allowed the new tester to be used for practicals during the training sessions and provided staff with hands-on familiarity with it . It also eliminated potential tester start-up problems. The scope of this custom-designed training program included rope constructions and properties, rope wear patterns and their quantification, basics of NDT inspections of ropes, familiarisation with the MD-120 instrument and its calibration, and procedures for definition and quantification of rope damage.

: CONCLUSIONS

: In an effort to upgrade reliability of winder rope inspections the NDT Unit of WASM has:
: 1. upgraded the testing apparatus;
: 2. defined and adopted suitable rope rejection criteria;
: 3. conducts the inspections in accordance with the relevant ASTM standard; and
: 4. trained the inspectors in the rope NDT techniques.
: These measures guarantee that inspection services supplied by the WASM NDT Unit follow the world's best practice and that the Unit provides its clients with reliable assessment of rope condition.

: APPENDIX 1
: Rope rejection criteria adapted from Kunn et al, 1993.


: BROKEN WIRES
: Described as loss of steel area of rope

: In one lay length:
: symmetric (LT 2/3 in three adjacent strands)
: asymmetric (MT 2/3 in three adjacent strands)
: In five lay lengths
: symmetric
: asymmetric

: LOSS OF DIAMETER
: Percentage of the larger of nominal or mid-rope
: diameter of new rope

: Wear and plastic deformation
: uniform around the rope
: mainly on one side of the rope
: Wear only
: uniform around the rope
: mainly on one side of the rope

: Any other causes
: increase or decrease in diameter

: CORROSION
: Identified by EM testing or visual inspection of rope

: Internal: indicated EM loss in area x multiplication factor established for
: the instrument
: External: pronounced pitting, slack wires, fractures in gussets

: DISTORTION
: Percentage of rope diameter established as for loss of diameter

: Waviness: setback of rope wave valley from its crest expressed as a per
: cent rope diameter.
: Angular bends: measured over two lay lengths
: Kinks: any kink is reason for discard

: FIBRE CORE
: Failure of core is reason for discard

: CHANGE IN LAY LENGTH
: General variation as percentage of nominal:
: increase
: decrease
: Local variation
: over six strand: percentage of the average of adjacent values

: HEAT DAMAGE
: Discard at any sign of heat damage such as:
: arcing, pits, discolouration, etc.

: MECHANICAL PROPERTIES
: Percentage reduction in values for the new rope

: Loss in breaking strength
: Loss in total strain energy to failure

: SHORT ROPE

: Less than three full turns on drum after cutting of front end samples, pulling in back end, or removal of defective ends of rope

: COMBINED EFFECTS

: Sum of individual fractions of the specified values, particularly of broken wires and loss of diameter, not to exceed value of 1.0

: RATE OF IN CREASE IN DETERIORATION

: The rope should be discarded if the maximum allowable levels of deterioration are expected before the next examination
: CRITERION
: (%)


:
: 8
: 5

: 16
: 10

:
: 10
: 7

: 7
: 7

:
: 8


:
: 7

: any


:
: 25

: 6

:
: 100
: 30

: 12


:
: 10
: 50


: REFERENCES

: ASTM standard E 1571-93. Standard Practice for Electromagnetic Examination for Ferromagnetic Steel Wire Rope.
: Fuchs, D and Schroeder, R, 1992. The safe load of winding ropes in large Koepe hoists - an assessment based on non destructive testing, OIPEEC Bulletin, No 63, (Reading Rope Research: Reading, UK)
: Geller, L B and Udd, J E, 1988. Comparative evaluation of mine-shaft wire-rope NDT instruments. Report MRL 88-78 (TR) CANMET: Energy, Mines and Resources Canada
: Geller, LB, Udd, J E, Blanchard, R and Daniel, K E, 1989. About electromagnetic testing in New Brunswick mines and related data. Report MRL 89-40(TR) CANMET: Energy, Mines and Resources Canada.
: Geller, L B, Rousseau, G and Poffenroth, D, 1990 Canada/NB MDA project on mine-shaft rope testing: stranded ropes with artificial defects. Report MRL 90-015 (TR) CANMET: Energy, Mines and Resources Canada.
: Golosinski, T S, 1995. Assessment of winder rope condition, in Proceedings Australasian Materials Conference, Perth, October
: Kuun, T C, Wainwright, E J, Dohm, A A R and van der Walt, W P, 1993 Condition assessment of winding ropes, in Proceedings Mine Hoisting 93 p 6.2.1 -6 (The Institution of Mining Electrical and Mining Mechanical Engineers of UK).
: Poffenroth, D N, 1989. Procedures and results of electromagnetic testing of mine hoist ropes using the LMA - TEST instruments, in Proceedings Wire Rope Discard Criteria pp 17.1 - 21 (Swiss Federal Institute of Technology (ETH).
: WA Mines Regulation Act 1946 and Regulations 1976. (WA Government Printer, 1991).
: Wavlets Analysis combined with NN




 
2714 views
08:44 Aug-14-1998
Nicholas Hebb
NDT failure analysis for wires/ cables

I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?


 
09:31 Aug-16-1998

Rolf Diederichs

Director, Editor, Publisher, Internet, PHP MySQL
NDT.net,
Germany,
Joined Nov 1998
602
Re: NDT failure analysis for wires/ cables : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

Nicholas Hebb,

thanks for bringing up an interesting topic.
However, your question is very broad.
For what kind of defects are you looking?
Broken wires? Thinning of isolation? etc.

Maybe this article can help you:
Wire cable testing using high resolution magnetic induction
http://www.ndt.net/article/0298/haller_e/haller_e.htm

Also NDTnet exhibitors, eg. Meraster, offering such kind of equipment.

Please submit some more details and try to use drawings (FTP)
which can show us the cable and depicts prospective defects and locations.

Rolf Diederichs



 
02:45 Aug-18-1998

Michael Trinidad

Consultant,
LMATS Pty Ltd ,
Australia,
Joined Jan 2003
138
Re: NDT failure analysis for wires/ cables : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

NonDestructive Testing (NDT) of Ropes
TS Golosinski

The paper reviews winder rope inspection procedures at the Non Destructive Testing (NDT) Unit of Western Australian School of Mines (WASM) and outlines measures taken to adopt the world's best practice. The measures include acquisition of a new type of rope tester, adoption of comprehensive rope rejection criteria, adoption of a standardrope inspection procedure and formal training of the wire rope inspectors.
BACKGROUND

In the mid- to late-1980s several catastrophic failures of winder ropes took place in Canadian mines. All failed ropes were periodically inspected with magnetic or electro-magnetic NDT instruments during service, some just days before the failure. Documented in detail by Geller et al (1989) these failures lead to an in-depth evaluation of the NDT rope inspection techniques in a study conducted jointly by the US Bureau of Mines and CANMET, a Canadian Federal Government research organisation. An initial stage of this study concentrated on review of past rope inspection practices and led the chief investigators to conclude that; "no more than some 50 per cent of the NDT estimates were within ± four per cent accuracy range' and that 'in a number of cases the rope breaking strength seemed to have diminished well beyond the amount permitted by the relevant provincial regulations' (Geller and Udd, 1988).
While the study has proven that introduction and use of NDT techniques for rope testing has greatly increased safety of winding , it identified a number of instances where the inspection results were outside the acceptable error range. Unreliability of many inspections was attributed to human related problems (Geller and Udd, 1988) and most notably from:

1. lack of adequate, uniform and generally available operator training procedures;

2. lack of adequate and uniform instrument and operator certification procedures; and

3. difficulties in obtaining reliable LBS (Loss of Breaking Strength) estimates based on measured LF (Local Fault)and LMA (Loss of Magnetic Area) data.

Other findings of the study indicated that rope testers providing both LMA and LF data allow for more accurate estimates of LBS than the single function instruments and that certain rope types, constructions and defects are particularly difficult to measure using the NDT techniques.
A follow-up study by CANMET compared accuracy of the ropeinspections conducted with several types and models of NDT rope testers. Ropes of various constructions and diameters were used in this study. It resulted in development of detailed recommendations on selection, design and operation of the NDT testers.
In Western Australia NDT inspections of winder ropes are conducted by the NDT Unit of WASM, a joint venture between the school and several mining companies. In addition to rope inspections the Unit also inspects rope attachments and various winder gear, and conducts a range of NDT tests using ultrasonic, penetrant, magnetic particles and other methods. Aware of the CANMET studies referred to above and driven by a desire to provide the industry with the highest quality service the management of the Unit launched a comprehensive review of rope inspection practice in place. As a result several aspects of the inspection were identified for possible upgrade. These were:

1. upgrade the rope testing equipment;

2. develop and adopt accurate rope rejection criteria;

3. adopt a standard rope inspection procedure; and

4. provide formal training for the inspectors.

NDT APPARATUS

Assessment of the condition of two rope testers owned by the NDT Unit indicated the need for an upgrade. A world wide search for a new tester was launched to facilitate this. At the same time feasibility and conditions of refurbishment of the testers at hand were investigated. This was found to be non competitive on commercial and technical grounds. The search for a new rope tester included identification of commercial suppliers and comparison of the relevant specifications. The base for comparisons, apart from technical specifications, were the desirable instrument characteristics defined in the CANMET study (Geller et al, 1990) as follows:

1. The instrument should be designed for adding, if so desired, electronic means to the paper chart records such as, for example, a frequency modulated (FM)tape recorder for recording, and for faithful playback of the following signals: (a) LMA, (b) LF. © test speed, (d) length, and (e) direction of measurements. The signal to noise ratio of the recording and play back process should be kept as high as possible in order that: (a) the added noise be less than 0.1 per cent of the LMA channel, and (b) the LF signal induced by a rope defect not be lost among electronic noise.

2. All control settings, such as zero and gain for both the LMA and LF signals should be equipped with a dial both readable, as wall as resetable, to within one-tenth of one per cent, so as to be able to exactly reconstruct the levels set during the original rope tests.
3. The electronic and magnetic characteristics of the instrument must be stable timewise (at least between factory calibration) and temperaturewise (between 20°C and +40°C for the sensor head and between +5°C and 35°C for the electronics)

4. The speed compensation must ensure that the amplitude of a discontinuity will remain constant regardless of the rope speed.

5. Both LMA and LF measurements should beindependent of rope speeds in the approximate range of zero to three m/s.

6. The instrument should produce charts with both LMA and LF traces.

7. The instrument's LMA, LF, distance and direction signals should be easily accessible for further recording and processing.

8. The range of the LMA measurements should extend to at least +5 per cent and -20 per cent in case of the largest rope size measurable by the instrument.

9. The chart paper advance should be proportional to the measured rope length.

10. The instrument should be capable of both the absolute and the relative metallic area measurements.

11. It should be possible to locate the sensor head at least 8 m from the control unit.

12. Influence of outside electromagnetic fields upon the output signals should be within acceptable limits.

13. The auxiliary magnetic field induced by the sensor head should be minimised.

14. The instrument should be easily portable, be capable of self-contained operation, its batteries should last for at least six hours of continuous operation, it should be sturdy and resistant to environmental effects (splash proof),it should have mounted on it, in an appropriate location, condensed instrument operating instructions and chart calibration procedures.

15. A warning signal must appear whenever the instrument's electronic circuit reaches saturation, ie whenever the data produced have been rendered invalid.

16. Instrument stability should be within one per cent LMA per hour (ie a ten per cent LMA reading should not drop to less than nine percent within an hour).

In total six rope tester manufacturers were identified with a record of worldwide sales and service, two in Canada and one each in the USA, Germany, Poland and South Africa. The specifications and characteristics of the first five testers were made available to the Unit and analysed in detail. While each of the manufacturers offers several tester models, the analysis was limited to the models best meeting the NDT Unit application criteria which weretesting of stranded winder ropes with diameter ranging between 15 mm and 60 mm. A summary of the findings of this analysis is presented in Table 1. Apart from technical specifications and those defined by CANMET additional conditions were included in the selection dealing with commercial terms, time and terms of delivery, and service support.

The bid review led to the decision to purchase the rope tester manufactured by Meraster of Poland, model MD-120, with the measuring head model GP2. In addition to scoring best in the comparison based on the CANMET criteria, and meeting other conditions, the tester allows for:

1. recording the measured data on a PC card for easy computer processing;

2. instantaneous recording of the LF signal from two measuring coils, each of different diameter, what in turn allows for accurate quantification of rope damage; and

3. automatic integration of rope damage over a selected rope length.

All three are identified on the sample strip chart recording shown in Figure 1. Delivery of the MD - 120 tester wad taken in October 1994. Since then it has been used as the main rope tester with the two older instruments used as back-up.

ROPE REJECTION CRITERIA

The purpose of rope inspections is to define the rope condition relative to that considered safe for the intended use. Rope condition is most commonly defined in terms of the loss of its breaking strength (LBS) from that of the new rope. The maximum permissible loss of LBS is then defined for a specific rope application and the measured LBS is compared against that maximum. Alternatively the safety factor for a specific rope application is defined and the rope is discarded when its remaining breaking strength is insufficient to secure this factor.

Neither the Western Australia Mines Regulations Act and Regulations 1976 nor the Australian Standards retail the winding rope wear and rejection criteria in a form which could be used in conjunction with the NDT inspections. The Regulations state that 'a rope … shall forthwith bewithdrawn from use when …( c ) Non-destructive examination of the rope using approved non-destructive testing equipment shows that continued use of the rope is not consistent with safe operation of the hoisting or haulage operation'. This leaves the responsibility for determination of the most appropriate rope rejection criteria with the NDT Unit. In the past the Unit used a criterion based on the maximum permissible loss of magnetic area of a rope (LMA signal) complemented by the maximum permissible number of broken wires (LF signal) and expressed as a loss of LBS. As a general rule the clients were recommended to discard a rope if its.

Dr Brandt Magnograph Rotescograph LMA 250 Meraster
Magnetisation

Instrument Type


Sensors

Head mass, kg

Console mass, kg
Electrical power
Rope diameter, mm
Rope speed, m/s
LMA averaging length, mm
Computer interface
Software
Inspector training
Availability
Compliance with
CANMET specifications rare earth
permanent m
dual function
LMA/LF

coils

35

27

batteries/AC
8 to 64

0.3 to 1.5
n/a

yes

included
1 day

20 weeks
meets most rare earth
permanent m
dual function
LMA/LF

Hall

45

35

batteries/AC
10 to 64

up to 3
200

yes

n/a
n/a

1995 or after
meets many ferrite
permanent m
dual function
LMA/LF

coils

40

20

AC only
10 to 64

up to 3
200

no

n/a
n/a

1995 or after
meets some rare earth
permanent m
dual function
LMA/LF

coils

32

22

batteries/AC
10 to 64

0* to 3
75

no

n/a
n/a

6 weeks
meets most rare earth
permanent m
four functions
LMA/LF/LF/INTEGR
Hall + two LF coil sets
42 (large) 7 (small)
12

batteries/AC
10 to 60

0.05 to 10
100

yes (+4MB internal)
available
1 week

12 weeks
meets all
exceeds many
* specified by the manufacturer.

LBS estimate amounted to ten percent or more of the breaking strength. While this criterion meets the requirements of the Regulations it leaves a margin for error in view of difficulties with relating the measured value of LMA to the actual LBS of a rope (Fuchs and Schroeder, 1992). The variety of winding rope constructions used in Western Australia contributes to the problem.
It is important for accurate assessment of rope condition that all forms of wear are taken into consideration (Poffenroth, 1989). While the indications of a NDT rope tester allow in most cases for quantification of rope wear, other forms of wear not detectable with the tester must be assessed as well. To research the best practice in this area a world-wide literature search for related information was undertaken. It yielded a large volume of data including several sets of comprehensive rope rejection criteria. Comparison of these led to the decision to adopt the set developed recently by the Angle American Corporation of South Africa (Kuun et al, 1993) These criteria are listed in Appendix 1.
Accuracy of rope condition assessment was significantly enhanced by the availability of two LF signals from two separate coils of the MD-120 tester. The signals allow for introduction of corrections reflecting the position and size of rope faults. As a result accurate quantification of rope damage is possible (Golosinski, 1995).

ROPE INSPECTION STANDARD

There is no Australian Standard which details the procedure for NDT testing and inspections of ropes. The procedure followed by the Unit was arrived at in an evolutionary manner by analysis of various relations observed during inspections. Advice of tester manufacturers and service staff was also solicited from time to time and contacts were made with the similar laboratories nationwide.
In 1993 the ASTM (American Society for Testing of Materials) adopted the standard E 1571-93 which defines the Standard Practice For Electromagnetic Examination For Ferromagnetic Steel Wire Rope. The standard was developed by the ASTM committee E-7: Non-Destructive Testing. Its development and approval was a direct result of USBM involvement in the research project conducted jointly with CANMET and referred to earlier.
The ASTM standard details the scope and sequence of activities which need to be included in the rope inspection, describes in detail the inspection procedure, imposes data processing and reporting requirements, and details the tester calibration procedure. In general the standard, if followed, reduces the risk of human errors and assures that the accuracy of rope condition assessment is as reliable as feasible. In absence of the corresponding Australian standards the ASTM standard on electromagnetic examination of ropes was adopted by the NDT Unit of WASM for conducting of all rope inspections.

TRAINING OF INSPECTORS

The NDT Unit inspectors have been certified by NATA (National Association of Testing Authorities) as qualified to conduct rope inspections. While this recognises their rope testing skills, the qualifications were acquired by hands-on inspection experience, self-education and contact with the tester manufacturer and service is very limited. Considering that the CANMET study identified lack of formal inspector training as one of the main factors contributing to unreliability of some inspections, an effort has been made to identify a suitable training program overseas or to develop one in-house.
A formal, structured training program for rope inspectors is currently being established by Anglo American Corporation in South Africa (Kuun et al, 1993). Inquiries have been made with that company regarding feasibility and conditions of training NDT Unit inspectors in South Africa. Somewhat similar programs have been established in Poland and Germany. All these programs meet the requirements defined in the CANMET study. Review of feasibility and conditions of having inspectors trained overseas lead to an agreement with the Rope Transport Laboratory of the University of Mining and Metallurgy in Cracow, Poland, for provision of a one-week course in NDT rope inspection techniques. This laboratory has a long history of involvement with rope inspections dating back over 30 years and was instrumental in development of the MD-120 tester discussed above.
Two NDT Unit staff took part in this training which was timed to coincide with the commissioning of the MD-120 tester acquired by WASM. This allowed the new tester to be used for practicals during the training sessions and provided staff with hands-on familiarity with it . It also eliminated potential tester start-up problems. The scope of this custom-designed training program included rope constructions and properties, rope wear patterns and their quantification, basics of NDT inspections of ropes, familiarisation with the MD-120 instrument and its calibration, and procedures for definition and quantification of rope damage.

CONCLUSIONS

In an effort to upgrade reliability of winder rope inspections the NDT Unit of WASM has:
1. upgraded the testing apparatus;
2. defined and adopted suitable rope rejection criteria;
3. conducts the inspections in accordance with the relevant ASTM standard; and
4. trained the inspectors in the rope NDT techniques.
These measures guarantee that inspection services supplied by the WASM NDT Unit follow the world's best practice and that the Unit provides its clients with reliable assessment of rope condition.

APPENDIX 1
Rope rejection criteria adapted from Kunn et al, 1993.

BROKEN WIRES
Described as loss of steel area of rope

In one lay length:
symmetric (LT 2/3 in three adjacent strands)
asymmetric (MT 2/3 in three adjacent strands)
In five lay lengths
symmetric
asymmetric

LOSS OF DIAMETER
Percentage of the larger of nominal or mid-rope
diameter of new rope

Wear and plastic deformation
uniform around the rope
mainly on one side of the rope
Wear only
uniform around the rope
mainly on one side of the rope

Any other causes
increase or decrease in diameter

CORROSION
Identified by EM testing or visual inspection of rope

Internal: indicated EM loss in area x multiplication factor established for
the instrument
External: pronounced pitting, slack wires, fractures in gussets

DISTORTION
Percentage of rope diameter established as for loss of diameter

Waviness: setback of rope wave valley from its crest expressed as a per
cent rope diameter.
Angular bends: measured over two lay lengths
Kinks: any kink is reason for discard

FIBRE CORE
Failure of core is reason for discard

CHANGE IN LAY LENGTH
General variation as percentage of nominal:
increase
decrease
Local variation
over six strand: percentage of the average of adjacent values

HEAT DAMAGE
Discard at any sign of heat damage such as:
arcing, pits, discolouration, etc.

MECHANICAL PROPERTIES
Percentage reduction in values for the new rope

Loss in breaking strength
Loss in total strain energy to failure

SHORT ROPE

Less than three full turns on drum after cutting of front end samples, pulling in back end, or removal of defective ends of rope

COMBINED EFFECTS

Sum of individual fractions of the specified values, particularly of broken wires and loss of diameter, not to exceed value of 1.0

RATE OF IN CREASE IN DETERIORATION

The rope should be discarded if the maximum allowable levels of deterioration are expected before the next examination
CRITERION
(%)


8
5

16
10


10
7

7
7


8


7

any


25

6


100
30

12


10
50

REFERENCES

ASTM standard E 1571-93. Standard Practice for Electromagnetic Examination for Ferromagnetic Steel Wire Rope.
Fuchs, D and Schroeder, R, 1992. The safe load of winding ropes in large Koepe hoists - an assessment based on non destructive testing, OIPEEC Bulletin, No 63, (Reading Rope Research: Reading, UK)
Geller, L B and Udd, J E, 1988. Comparative evaluation of mine-shaft wire-rope NDT instruments. Report MRL 88-78 (TR) CANMET: Energy, Mines and Resources Canada
Geller, LB, Udd, J E, Blanchard, R and Daniel, K E, 1989. About electromagnetic testing in New Brunswick mines and related data. Report MRL 89-40(TR) CANMET: Energy, Mines and Resources Canada.
Geller, L B, Rousseau, G and Poffenroth, D, 1990 Canada/NB MDA project on mine-shaft rope testing: stranded ropes with artificial defects. Report MRL 90-015 (TR) CANMET: Energy, Mines and Resources Canada.
Golosinski, T S, 1995. Assessment of winder rope condition, in Proceedings Australasian Materials Conference, Perth, October
Kuun, T C, Wainwright, E J, Dohm, A A R and van der Walt, W P, 1993 Condition assessment of winding ropes, in Proceedings Mine Hoisting 93 p 6.2.1 -6 (The Institution of Mining Electrical and Mining Mechanical Engineers of UK).
Poffenroth, D N, 1989. Procedures and results of electromagnetic testing of mine hoist ropes using the LMA - TEST instruments, in Proceedings Wire Rope Discard Criteria pp 17.1 - 21 (Swiss Federal Institute of Technology (ETH).
WA Mines Regulation Act 1946 and Regulations 1976. (WA Government Printer, 1991).



 
03:04 Aug-19-1998

Michael Trinidad

Consultant,
LMATS Pty Ltd ,
Australia,
Joined Jan 2003
138
Re: NDT failure analysis for wires/ cables I apologise the tables in the paper I posted became jumbled in the transfer. If anyone requires the tables I can email the paper for your information.


 
05:29 Aug-19-1998
Kaz Zawada
Re: NDT failure analysis for wires/ cables : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: NonDestructive Testing (NDT) of Ropes
: TS Golosinski

As an addition to Michael Trinidad post:
If you want learn more on wire rope NDT and inspection equipment,
you can find some background information in an article at
http://polbox.com/n/ndtropes/general.html


 
01:58 Jan-05-1999
w hickman
Re: NDT failure analysis for wires/ cables : : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: : Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: : NonDestructive Testing (NDT) of Ropes
: : TS Golosinski

: As an addition to Michael Trinidad post:
: If you want learn more on wire rope NDT and inspection equipment,
: you can find some background information in an article at
: http://polbox.com/n/ndtropes/general.html





 
04:44 Jul-20-1999
Cohen
Re: NDT failure analysis for wires/ cables Please visit our web site: http://www.case-technologies.com
or contact me for information about our new cable (UTS - Ultimate Tensile Strength) monitoring technology.

: : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: : Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: : NonDestructive Testing (NDT) of Ropes
: : TS Golosinski

: As an addition to Michael Trinidad post:
: If you want learn more on wire rope NDT and inspection equipment,
: you can find some background information in an article at
: http://polbox.com/n/ndtropes/general.html




 
04:51 Jul-20-1999
Cohen
Re: NDT failure analysis for wires/ cables Please visit our web site for information about our new technology

: : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: NonDestructive Testing (NDT) of Ropes
: TS Golosinski

: The paper reviews winder rope inspection procedures at the Non Destructive Testing (NDT) Unit of Western Australian School of Mines (WASM) and outlines measures taken to adopt the world's best practice. The measures include acquisition of a new type of rope tester, adoption of comprehensive rope rejection criteria, adoption of a standard rope inspection procedure and formal training of the wire rope inspectors.
: BACKGROUND

: In the mid- to late-1980s several catastrophic failures of winder ropes took place in Canadian mines. All failed ropes were periodically inspected with magnetic or electro-magnetic NDT instruments during service, some just days before the failure. Documented in detail by Geller et al (1989) these failures lead to an in-depth evaluation of the NDT rope inspection techniques in a study conducted jointly by the US Bureau of Mines and CANMET, a Canadian Federal Government research organisation. An initial stage of this study concentrated on review of past rope inspection practices and led the chief investigators to conclude that; "no more than some 50 per cent of the NDT estimates were within ± four per cent accuracy range' and that 'in a number of cases the rope breaking strength seemed to have diminished well beyond the amount permitted by the relevant provincial regulations' (Geller and Udd, 1988).
: While the study has proven that introduction and use of NDT techniques for rope testing has greatly increased safety of winding , it identified a number of instances where the inspection results were outside the acceptable error range. Unreliability of many inspections was attributed to human related problems (Geller and Udd, 1988) and most notably from:

: 1. lack of adequate, uniform and generally available operator training procedures;

: 2. lack of adequate and uniform instrument and operator certification procedures; and

: 3. difficulties in obtaining reliable LBS (Loss of Breaking Strength) estimates based on measured LF (Local Fault)and LMA (Loss of Magnetic Area) data.

: Other findings of the study indicated that rope testers providing both LMA and LF data allow for more accurate estimates of LBS than the single function instruments and that certain rope types, constructions and defects are particularly difficult tomeasure using the NDT techniques.
: A follow-up study by CANMET compared accuracy of the rope inspections conducted with several types and models of NDT rope testers. Ropes of various constructions and diameters were used in this study. It resulted in development of detailed recommendations on selection, design and operation of the NDT testers.
: In Western Australia NDT inspections of winder ropes are conducted by the NDT Unit of WASM, a joint venture between the school and several mining companies. In addition to rope inspections the Unit also inspects rope attachments and various winder gear, and conducts a range of NDT tests using ultrasonic, penetrant, magnetic particles and other methods. Aware of the CANMET studies referred to above and driven by a desire to provide the industry with the highest quality service the management of the Unit launched a comprehensive review of rope inspection practice in place. As a result several aspects of the inspection were identified for possible upgrade. Thesewere:

: 1. upgrade the rope testing equipment;

: 2. develop and adopt accurate rope rejection criteria;

: 3. adopt a standard rope inspection procedure; and

: 4. provide formal training for the inspectors.

: NDT APPARATUS

: Assessment of the condition of two rope testers owned by the NDT Unit indicated the need for an upgrade. A world wide search for a new tester was launched to facilitate this. At the same time feasibility and conditions of refurbishment of the testers at hand were investigated. This was found to be non competitive on commercial and technical grounds. The search for a new rope tester included identification of commercial suppliers and comparison of the relevant specifications. The base for comparisons, apart from technical specifications, were the desirable instrument characteristics defined in the CANMET study (Geller et al, 1990) as follows:

: 1. The instrument should be designed for adding, if so desired, electronic means to the paper chart records such as, for example, a frequency modulated (FM)tape recorder for recording, and for faithful playback of the following signals: (a) LMA, (b) LF. © test speed, (d) length, and (e) direction of measurements. The signal to noise ratio of the recording and play back process should be kept as high as possible in order that: (a) the added noise be less than 0.1 per cent of the LMA channel, and (b) the LF signal induced by a rope defect not be lost among electronic noise.

: 2. All control settings, such as zero and gain for both the LMA and LF signals should be equipped with a dial both readable, as wall as resetable, to within one-tenth of one per cent, so as to be able to exactly reconstruct the levels set during the original rope tests.
: 3. The electronic and magnetic characteristics of the instrument must be stable timewise (at least between factory calibration) and temperaturewise (between 20°C and +40°C for the sensor head and between +5°C and 35°C for the electronics)

: 4. The speed compensation must ensure that the amplitude of a discontinuity will remain constant regardless of the rope speed.

: 5. Both LMA and LF measurements should be independent of rope speeds in the approximate range of zero to three m/s.

: 6. The instrument should produce charts with both LMA and LF traces.

: 7. The instrument's LMA, LF, distance and direction signals should be easily accessible for further recording and processing.

: 8. The range of the LMA measurements should extend to at least +5 per cent and -20 per cent in case of the largest rope size measurable by the instrument.

: 9. The chart paper advance should be proportional to the measured rope length.

: 10. The instrument should be capable of both the absolute and the relative metallic area measurements.

: 11. It should be possible to locate the sensor head at least 8 m from the control unit.

: 12. Influence of outside electromagnetic fields upon the output signals should be within acceptable limits.

: 13. The auxiliary magnetic field induced by the sensor head should be minimised.

: 14. The instrument should be easily portable, be capable of self-contained operation, its batteries should last for at least six hours of continuous operation, it should be sturdy and resistant to environmental effects (splash proof),it should have mounted on it, in an appropriate location, condensed instrument operating instructions and chart calibration procedures.

: 15. A warning signal must appear whenever the instrument's electronic circuit reaches saturation, ie whenever the data produced have been rendered invalid.

: 16. Instrument stability should be within one per cent LMA per hour (ie a ten per cent LMA reading should not drop to less than nine percent within an hour).

: In total six rope tester manufacturers were identified with a record of worldwide sales and service, two in Canada and one each in the USA, Germany, Poland and South Africa. The specifications and characteristics of the first five testers were made available to the Unit and analysed in detail. While each ofthe manufacturers offers several tester models, the analysis was limited to the models best meeting the NDT Unit application criteria which were testing of stranded winder ropes with diameter ranging between 15 mm and 60 mm. A summary of the findings of this analysis is presented in Table 1. Apart from technical specifications and those defined by CANMET additional conditions were included in the selection dealing with commercial terms, time and terms of delivery, and service support.

: The bid review led to the decision to purchase the rope tester manufactured by Meraster of Poland, model MD-120, with the measuring head model GP2. In addition to scoring best in the comparison based on the CANMET criteria, and meeting other conditions, the tester allows for:

: 1. recording the measured data on a PC card for easy computer processing;

: 2. instantaneous recording of the LF signal from two measuring coils, each of different diameter, what in turn allows for accurate quantification of rope damage; and

:3. automatic integration of rope damage over a selected rope length.

: All three are identified on the sample strip chart recording shown in Figure 1. Delivery of the MD - 120 tester wad taken in October 1994. Since then it has been used as the main rope tester with the two older instruments used as back-up.

: ROPE REJECTION CRITERIA

: The purpose of rope inspections is to define the rope condition relative to that considered safe for the intended use. Rope condition is most commonly defined in terms of the loss of its breaking strength (LBS) from that of the new rope. The maximum permissible loss of LBS is then defined for a specific rope application and the measured LBS is compared against that maximum. Alternatively the safety factor for a specific rope application is defined and the rope is discarded when its remaining breaking strength is insufficient to secure this factor.

: Neither the Western Australia Mines Regulations Act and Regulations 1976 nor the Australian Standards retail the winding rope wear and rejection criteria in a form which could be used in conjunction with the NDT inspections. The Regulations state that 'a rope … shall forthwith be withdrawn from use when …( c ) Non-destructive examination of the rope using approved non-destructive testing equipment shows that continued use of the rope is not consistent with safe operation of the hoisting or haulage operation'. This leaves the responsibility for determination of the most appropriate rope rejection criteria with the NDT Unit. In the past the Unit used a criterion based on the maximum permissible loss of magnetic area of a rope (LMA signal) complemented by the maximum permissible number of broken wires (LF signal) and expressed as a loss of LBS. As a general rule the clients were recommended to discard a rope if its.

: Dr Brandt Magnograph Rotescograph LMA 250 Meraster
: Magnetisation

: Instrument Type

:
: Sensors

: Head mass, kg

: Console mass, kg
: Electrical power
: Rope diameter, mm
: Rope speed, m/s
: LMA averaging length, mm
: Computer interface
: Software
: Inspector training
: Availability
: Compliance with
: CANMET specifications rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 35

: 27

: batteries/AC
: 8 to 64

: 0.3 to 1.5
: n/a

: yes

: included
: 1 day

: 20 weeks
: meets most rare earth
: permanent m
: dual function
: LMA/LF

: Hall

: 45

: 35

: batteries/AC
: 10 to 64

: up to 3
: 200

: yes

: n/a
: n/a

: 1995 or after
: meets many ferrite
: permanent m
: dual function
: LMA/LF

: coils

: 40

: 20

: AC only
: 10 to 64

: up to 3
: 200

: no

: n/a
: n/a

: 1995 or after
: meets some rare earth
: permanent m
: dual function
: LMA/LF

: coils

: 32

: 22

: batteries/AC
: 10 to 64

: 0* to 3
: 75

: no

: n/a
: n/a

: 6 weeks
: meets most rare earth
: permanent m
: four functions
: LMA/LF/LF/INTEGR
: Hall + two LF coil sets
: 42 (large) 7 (small)
: 12

: batteries/AC
: 10 to 60

: 0.05 to 10
: 100

: yes (+4MB internal)
: available
: 1 week

: 12 weeks
: meets all
: exceeds many
: * specified by the manufacturer.

: LBS estimate amounted to ten percent or more of the breaking strength. While this criterion meets the requirements of the Regulations it leaves a margin for error in view of difficulties with relating the measured value of LMA to the actual LBS of a rope (Fuchs and Schroeder, 1992). The variety of winding rope constructions used in Western Australia contributes to the problem.
: It is important for accurate assessment of rope condition that all forms of wear are taken into consideration (Poffenroth, 1989). While the indications of a NDT rope tester allow in most cases for quantification of rope wear, other forms of wear not detectable with the tester must be assessed as well. To research the best practice in this area a world-wide literature search for related information was undertaken. It yielded a large volume of data including several sets of comprehensive rope rejection criteria. Comparison of these led to the decision to adopt the set developed recently by the Angle American Corporation of South Africa (Kuun et al, 1993) These criteria are listed in Appendix 1.
: Accuracy of rope condition assessment was significantly enhanced by the availability of two LF signals from two separate coils of the MD-120 tester. The signals allow for introduction of corrections reflecting the position and size of rope faults. As a result accurate quantification of rope damage is possible (Golosinski, 1995).

: ROPE INSPECTION STANDARD

: There is no Australian Standard which details the procedure for NDT testing and inspections of ropes. The procedure followed by the Unit was arrived at in an evolutionary manner by analysis of various relations observed during inspections. Advice of tester manufacturers and service staff was also solicited from time to time and contacts were made with the similar laboratories nationwide.
: In 1993 the ASTM (American Society for Testing of Materials) adopted the standard E 1571-93 which defines the Standard Practice For Electromagnetic Examination For Ferromagnetic Steel Wire Rope. The standard was developed by the ASTM committee E-7: Non-Destructive Testing. Its development and approval was a direct result of USBM involvement in the research project conducted jointly with CANMET and referred to earlier.
: The ASTM standard details the scope and sequence of activities which need to be included in the rope inspection, describes in detail the inspection procedure, imposes data processing and reporting requirements, and details the tester calibration procedure. In general the standard, if followed, reduces the risk of human errors and assures that the accuracy of rope condition assessment is as reliable as feasible. In absence of the corresponding Australian standards the ASTM standard on electromagnetic examination of ropes was adopted by the NDT Unit of WASM for conducting of all rope inspections.

: TRAINING OF INSPECTORS

: The NDT Unit inspectors have been certified by NATA (National Association of Testing Authorities) as qualified to conduct rope inspections. While this recognises their rope testing skills, the qualifications were acquired by hands-on inspection experience, self-education and contact with the tester manufacturer and service is very limited. Considering that the CANMET study identified lack of formal inspector training as one of the main factors contributing to unreliability of some inspections, an effort has been made to identify a suitable training program overseas or to develop one in-house.
: A formal, structured training program for rope inspectors is currently being established by Anglo American Corporation in South Africa (Kuun et al, 1993). Inquiries have been made with that company regarding feasibility and conditions of training NDT Unit inspectors in South Africa. Somewhat similar programs have been established in Poland and Germany. All these programs meet the requirements defined in the CANMET study. Review of feasibility and conditions of having inspectors trained overseas lead to an agreement with the Rope Transport Laboratory of the University of Mining and Metallurgy in Cracow, Poland, for provision of a one-week course in NDT rope inspection techniques. This laboratory has a long history of involvement with rope inspections dating back over 30 years and was instrumental in development of the MD-120 tester discussed above.
: Two NDT Unit staff took part in this training which was timed to coincide with the commissioning of the MD-120 tester acquired by WASM. This allowed the new tester to be used for practicals during the training sessions and provided staff with hands-on familiarity with it . It also eliminated potential tester start-up problems. The scope of this custom-designed training program included rope constructions and properties, rope wear patterns and their quantification, basics of NDT inspections of ropes, familiarisation with the MD-120 instrument and its calibration, and procedures for definition and quantification of rope damage.

: CONCLUSIONS

: In an effort to upgrade reliability of winder rope inspections the NDT Unit of WASM has:
: 1. upgraded the testing apparatus;
: 2. defined and adopted suitable rope rejection criteria;
: 3. conducts the inspections in accordance with the relevant ASTM standard; and
: 4. trained the inspectors in the rope NDT techniques.
: These measures guarantee that inspection services supplied by the WASM NDT Unit follow the world's best practice and that the Unit provides its clients with reliable assessment of rope condition.

: APPENDIX 1
: Rope rejection criteria adapted from Kunn et al, 1993.


: BROKEN WIRES
: Described as loss of steel area of rope

: In one lay length:
: symmetric (LT 2/3 in three adjacent strands)
: asymmetric (MT 2/3 in three adjacent strands)
: In five lay lengths
: symmetric
: asymmetric

: LOSS OF DIAMETER
: Percentage of the larger of nominal or mid-rope
: diameter of new rope

: Wear and plastic deformation
: uniform around the rope
: mainly on one side of the rope
: Wear only
: uniform around the rope
: mainly on one side of the rope

: Any other causes
: increase or decrease in diameter

: CORROSION
: Identified by EM testing or visual inspection of rope

: Internal: indicated EM loss in area x multiplication factor established for
: the instrument
: External: pronounced pitting, slack wires, fractures in gussets

: DISTORTION
: Percentage of rope diameter established as for loss of diameter

: Waviness: setback of rope wave valley from its crest expressed as a per
: cent rope diameter.
: Angular bends: measured over two lay lengths
: Kinks: any kink is reason for discard

: FIBRE CORE
: Failure of core is reason for discard

: CHANGE IN LAY LENGTH
: General variation as percentage of nominal:
: increase
: decrease
: Local variation
: over six strand: percentage of the average of adjacent values

: HEAT DAMAGE
: Discard at any sign of heat damage such as:
: arcing, pits, discolouration, etc.

: MECHANICAL PROPERTIES
: Percentage reduction in values for the new rope

: Loss in breaking strength
: Loss in total strain energy to failure

: SHORT ROPE

: Less than three full turns on drum after cutting of front end samples, pulling in back end, or removal of defective ends of rope

: COMBINED EFFECTS

: Sum of individual fractions of the specified values, particularly of broken wires and loss of diameter, not to exceed value of 1.0

: RATE OF IN CREASE IN DETERIORATION

: The rope should be discarded if the maximum allowable levels of deterioration are expected before the next examination
: CRITERION
: (%)


:
: 8
: 5

: 16
: 10

:
: 10
: 7

: 7
: 7

:
: 8


:
: 7

: any


:
: 25

: 6

:
: 100
: 30

: 12


:
: 10
: 50


: REFERENCES

: ASTM standard E 1571-93. Standard Practice for Electromagnetic Examination for Ferromagnetic Steel Wire Rope.
: Fuchs, D and Schroeder, R, 1992. The safe load of winding ropes in large Koepe hoists - an assessment based on non destructive testing, OIPEEC Bulletin, No 63, (Reading Rope Research: Reading, UK)
: Geller, L B and Udd, J E, 1988. Comparative evaluation of mine-shaft wire-rope NDT instruments. Report MRL 88-78 (TR) CANMET: Energy, Mines and Resources Canada
: Geller, LB, Udd, J E, Blanchard, R and Daniel, K E, 1989. About electromagnetic testing in New Brunswick mines and related data. Report MRL 89-40(TR) CANMET: Energy, Mines and Resources Canada.
: Geller, L B, Rousseau, G and Poffenroth, D, 1990 Canada/NB MDA project on mine-shaft rope testing: stranded ropes with artificial defects. Report MRL 90-015 (TR) CANMET: Energy, Mines and Resources Canada.
: Golosinski, T S, 1995. Assessment of winder rope condition, in Proceedings Australasian Materials Conference, Perth, October
: Kuun, T C, Wainwright, E J, Dohm, A A R and van der Walt, W P, 1993 Condition assessment of winding ropes, in Proceedings Mine Hoisting 93 p 6.2.1 -6 (The Institution of Mining Electrical and Mining Mechanical Engineers of UK).
: Poffenroth, D N, 1989. Procedures and results of electromagnetic testing of mine hoist ropes using the LMA - TEST instruments, in Proceedings Wire Rope Discard Criteria pp 17.1 - 21 (Swiss Federal Institute of Technology (ETH).
: WA Mines Regulation Act 1946 and Regulations 1976. (WA Government Printer, 1991).




 
03:17 Sep-12-2001

Alexander Mironenko

Sales,
INTRON PLUS Ltd.,
Russia,
Joined Sep 2001
17
Re: NDT failure analysis for wires/ cables : Please visit our web site: http://www.case-technologies.com
: or contact me for information about our new cable (UTS - Ultimate Tensile Strength) monitoring technology.

: : : : I run a test laboratory for a cable manufacturer, and I am interested in any test methods that would provide an internal visual depiction of failures caused by flex tests in the lab or field failures.

: : : : We have tried standard x-ray before without much sucess. Are there x-ray laminography or UT systems/services available for such an application?

: : : Like Rolf I am unsure of what application or type of cable you wish to inspect. I have attached a paper detailing how we went about selecting the best equipment for the inspection of steel wire ropes for your interest it also gives basic information about the method.

: : : NonDestructive Testing (NDT) of Ropes
: : : TS Golosinski

: : As an addition to Michael Trinidad post:
: : If you want learn more on wire rope NDT and inspection equipment,
: : you can find some background information in an article at
: : http://polbox.com/n/ndtropes/general.html

:Hello! In addition you may visit www.intron.ru to see how we suggest to test wire ropes with our new magnetic instruments. Some recent publications on the matter are available there.




 
02:58 Nov-08-2001
Duane Yee
Cables and Cable Connections I need analysis of Cables and Cable joints for a power producting generator to determine possible causes of failure.

Can you be of help - or can you steer me in the correct direction.

Duane Yee
enXco
N. Palm Springs, CA 92258


 


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