UT
|
Improved Sound Field Penetration Using Piezocomposite Transducers
The performance characteristics of the transducer can significantly influence system performance. This presentation explains a major reason
for performance improvement gained by piezocomposites. A mathematical model is used to predict the received waveform for both a monolithic
PZT transducer and a piezoc omposite design. Piezoeomposite designs provide both broad bandwidth and high signal amplitudes making them
more suitable for use on lossy test materials.
By Paul A. Meyer, Ph.D. Krautkramer Branson.
Guided Wave Applications of Piezocomposite Transducers  inside.
We've added a sound file for this previous article by Paul Meyer.
| 
|
UT
|
Ultrasonic beams focusing in piezoelectric crystals and ferroelectric ceramics by application of a nonuniform electric field
A new solution to the problem of controllable focusing of ultrasonic beams is given. It consists in that the application of a nonuniform
electric field of special configuration in piezoelectrics and ferroelectric ceramics causes a quadratic change of the velocity in the
cross-section of an ultrasonic beam A new type of a controllable device for acoustic beams focusing - an electroacoustic lens - has
been made. The dependence has been established of the focal length on the lens length and aperture as well as on the control voltage
value and electroacoustic parameters of the material.
By V.N.Belyi, N.S.Kazak V.K.Pavlenko, A.G.Mashchenko and F.M.Severin, Stepanov Institute of Physics, Academy of Sciences of Belarus |
|
UT
|
Split-Spectrum Processing for Nondestructive Testing
Air has been found to be present in circulating water lines at electric power generating stations. Macroscopic air pockets of interest are
on the order of inches to feet in size and have been found to lie along the top of the pipe. We have developed a technique to detect air
pockets using ultrasonic nondestructive evaluation. Specifically, we use pulse-echo ultrasonic techniques on concrete (the pipe
material) and aluminun (as a reference) samples.
By Kwong Ki Yau, Worcester Polytechnic Institute |
|
UT
|
Practicle experiences with automated ultrasonic testing of manual welded pipelines [D]
A Multi-probe concept is a precondition for the test demands of an ultrasonic weld test during the assembling of pipelines. The weld must be tested completely during one turn around the pipe circumference.
The equipment concept is introduced which worked satisfied in the field.
by H. Heckhäuser, H. Thiele, Herne; B. Rühlmann, Kassel |
|
IRT
|
NDT of materials using lock-in thermography
[D]
Locking Thermography is a non-contact non-destructive measuring method which combines the advantages of
photothermal radiography and thermography, while avoiding the disadvantages of both. Datong Wu developed a method that requires a short image formatting time even for the low frequencies of heat generation, thus facilitating rapid structure recognition.
By Datong Wu, Instiute for polymer testing and polymer science of the University of
Stuttgart |
|
UT
|
An Ultrasonic Sensor for
High-Temperature Materials Processing
A sensor has been developed and tested that is capable of emitting and receiving
ultrasonic energy at temperatures exceeding 900° and pressures above 150 MPa. The
sensor works with standard ultrasonic pulser- receivers and has demonstrated the capability of measuring workpiece deformation during hot isostatic pressing. Details of the sensor design, performance, and coupling of the ultrasound to the workpiece are described. Ultrasonic data acquired by the sensor in-situ during hot-isostatic-pressing runs are presented.
A Virtual Article of the Journal of Materials (JOM).
Published monthly by The Minerals, Metals & Materials Society (TMS)
JOM is a technical journal devoted to exploring the many aspects of
materials science and engineering. Visit more Online Articles. Or you may Search other NDT themes on the great TMS Homepage.
|
|
UT
|
A Computerized Imaging System for Ultrasonic Inspection of Steel Bridge Structures
By Igor N. Komsky and Jan D. Achenbach, November 1995
A Virtual Article on the Infrastructure Technology Institute (ITI) Home Page of the Northwestern University Evanston, IL.
|
