where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
1198 views
Technical Discussions
Marco Di Fusco
Marco Di Fusco
22:32 May-07-2018
Ultrasonic methods


Hi I would have a couple of questions for a thesis work on ultrasonic methods. I am experimenting on steel and aluminum bars of about one meter with a double element probe.Someone can tell me in detail what is due to the different attenuation of the signal in the two different materials? Also what frequency of the signal is optimal for you in the case of steel bars of greater length (6 meters)

 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 856

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
856
21:25 May-09-2018
Re: Ultrasonic methods
In Reply to Marco Di Fusco at 22:32 May-07-2018 (Opening).

Marco,

I would like to know your level of understanding and knowledge of ultrasonic inspection. I assume that for someone to do a thesis on the subject, they must have a bachelor's degree in a à related field, like engineering or metallurgy. The questions you are asking are very basic regarding this type of inspection and the axis of your inspection is not mentioned. If the surface width or thickness was available for scanning, I wouldn't scanned it lengthwise because of the beam spread and of mode conversion resulting from it.

As for the difference in attenuation, are both materials from similar process like rolled product. What is the heat treatment, the grain size will probably be different. what is the chimical composition of each materials. If you can answer all these questions, you will find all you are looking for.

1
 
 Reply 
 
S V Swamy
Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex , India, Joined Feb 2001, 787

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
787
22:21 May-09-2018
Re: Ultrasonic methods
In Reply to Marco Di Fusco at 22:32 May-07-2018 (Opening).

Why are you trying to use dual element probe instead of say through transmission technique? Why not use shorter length specimens if you are interested only in studying attenuation? Thus your questions generate other questions and without sufficient clarity of what you are trying to do, right answers may not come....

Trying to inspect a 6 meter long bar from end is in my opinion, not feasible. If the aim is to study the internal soundness of the bar, there are many efficient conventional ultrasonic testing techniques that use a combination of normal and angle beam probes. Also, the process of manufacture of the bars needs to be studied and the scope for generation of discontinuities minimised. Quality has to be manufactured and not inspected into a product.

1
 
 Reply 
 
bgavsampath
NDT Inspector,
technician and instructure , Sri Lanka, Joined May 2018, 2

bgavsampath

NDT Inspector,
technician and instructure ,
Sri Lanka,
Joined May 2018
2
01:52 May-12-2018
Re: Ultrasonic methods
In Reply to Marco Di Fusco at 22:32 May-07-2018 (Opening).

when we are using probes for welding scanning, how much the surface temperature at scanning area minimum and maximum

1
 
 Reply 
 
Luis Marka
Luis Marka
14:19 May-12-2018
Re: Ultrasonic methods
In Reply to bgavsampath at 01:52 May-12-2018 .

Mr. Bgavsampath, temperature limits, as well as maximum temperature difference between calibration block and part to be inspected should be clearly stated in your inspection procedure. If this information is missing, ask your Level 3 supervisor.

3
 
 Reply 
 
Krishna bharathi
NDT Inspector,
India, Joined Jun 2015, 15

Krishna bharathi

NDT Inspector,
India,
Joined Jun 2015
15
18:45 May-12-2018
Re: Ultrasonic methods
In Reply to bgavsampath at 01:52 May-12-2018 .

Some clients like oil & gas requires +/- 14" celsius from the calibration temp

1
 
 Reply 
 
Marco Di Fusco
Engineering,
Italy, Joined May 2018, 2

Marco Di Fusco

Engineering,
Italy,
Joined May 2018
2
10:19 May-15-2018
Re: Ultrasonic methods
In Reply to Michel Couture at 21:25 May-09-2018 .

Hi, unfortunately, I am a civil engineer and these topics are not covered in my studies. Together with the mechanical engineering department of the University of Cassino I decided to undertake this long and complex thesis work. I understand that these are basic questions and thank you for answering me.

 
 Reply 
 
Marco Di Fusco
Engineering,
Italy, Joined May 2018, 2

Marco Di Fusco

Engineering,
Italy,
Joined May 2018
2
11:08 May-15-2018
Re: Ultrasonic methods
In Reply to S V Swamy at 22:21 May-09-2018 .

Hi, we use the double probe because it is the one we supplied. For "through-transmission" techniques it would take two transmitting and receiving probes and at the moment we do not have the availability. It is also a study for the inspection of anchorage bars for support works in the geotechnical field. As you well know, a steel bar anchored in rock has a limited contact section in the anchor head, so the pulse-echo methodology is the most suitable to evaluate internal solidity.

 
 Reply 
 
S V Swamy
Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex , India, Joined Feb 2001, 787

S V Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
787
12:31 May-15-2018
Re: Ultrasonic methods
In Reply to Marco Di Fusco at 11:08 May-15-2018 .

I am a metallurgist and am not familiar with this particular application but have the following comments which may or may not help.

If the bars are to be tested while they are being manufactured (I would expect them to be manufactured using a combination of forging and rolling), there are many conventional, well established techniques for detection of discontinuities. On the other hand, if the bars are already in service, you may need a totally different approach and I confess that I have no real idea of what would work best since that is not my area of expertise.

Best wishes to you in your quest for the right solution.

 
 Reply 
 
Ed Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1282

Ed Ginzel

R & D, -
Materials Research Institute,
Canada,
Joined Nov 1998
1282
14:06 May-15-2018
Re: Ultrasonic methods
In Reply to Marco Di Fusco at 11:08 May-15-2018 .

Marco, as I understand them, there can be anchor bolts cast into concrete or you can drill holes (in rock) and insert a bolt that has an expansion mechanism that expands into the rock. The diameter of the rod is generally small (e.g. 2-10 cm). For long anchors the traditional method is to use a single element probe in pulse-echo mode. The frequency and diameter of the probe will have an effect on the apparent attenuation. If there is a lot of beam spread there will be many mode conversions and reflection and transmission (into concrete) losses. These attenuation losses increase with any corrosion or fatigue damage in the rod. Your dual element probe will probably have a roof angle so the transmitted beam will immediately be directed to the side of the rod and the receiving element will be more sensitive to reflections coming from the opposite side of the rod so it is not ideal to get a good signal from the far end of the rod. Since the most likely point of failure in anchor bolts used in concrete is between the leveling nuts, just a few centimetres below the contact point of the probe, perhaps the dual element will be useful to locate the corrosion or fatigue crack. But most people seem to start off investigating the entire length when possible. See a useful presentation at http://cait.rutgers.edu/system/files/u10/Stachel-Abernathy_Anchor_Bolt_Testing.pdf

1
 
 Reply 
 

Product Spotlight

Ultrasonic Testing Immersion Tanks with Unmatched Scanning Features

TecScan’s non-destructive testing Ultrasonic Immersion Tanks & scanners are designed for high pe
...
rformance and demanding NDT testing applications. Our Scan3D™ line of High Precision Immersion Tanks are specifically designed for automated ultrasonic testing of complex composites parts used in aerospace and industrial applications.
>

Varex Imaging Large Field of View (FOV) Digital Detector Arrays (DDAs)

A larger FOV DDA can reduce the space and volume of the X-ray inspection system on the factory floor
...
, enable faster scanning times, better throughput and better resolution images at a lower dose. Customers can also save time and money. With these benefits in mind, Varex Imaging has designed a family of large FOV detectors (4343HE, XRD 1611, 4343DX-I, 4343CT) for our industrial imaging customers.
>

UCI Hardness Tester NOVOTEST T-U2

UCI hardness tester NOVOTEST T-U2 is is used for non-destructive hardness testing of: metals and
...
alloys by scales of hardness: Rockwell (HRC), Brinell (HB), Vickers (HV); non-ferrous metals, alloys of iron etc., and using five additional scales for calibration; with tensile strength (Rm) scale determines the tensile strength of carbon steel pearlitic products by automatic recalculation from Brinell (HB) hardness scale.
>

High-performance Linear Phased Array Probes

Available to order from stock in a range of 5MHz – 7.5MHz and from 16 to 64 elements. Designed w
...
ith piezo-composite elements, Phoenix phased array probes provide high-resolution imaging to maximise sensitivity; accurate ultrasonic detection and sizing of defects in welds; and effective corrosion mapping. Housed in a rugged stainless steel case for on-site industrial NDT applications.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window