The computer progam UTDefect has been developed to model ultrasonic testing in homogeneous, isotropic and relatively thick-walled components. The model is complete in that it includes transmitting and receiving probes, defects and calibration by a side-drilled of flatbottomed hole. The results are given as A, B and C scans. To solve the wave propagation problems exact integral equation methods are employed with some not very restrictive far field assumptions. Approximations like ray tracing, geometrical theory of diffraction or Kirchhoff theory are thus avoided. The defects and probes can not be too close, but there is no upper limit on their separation.
The list of defects in UTDefect includes strip-like and circular cracks, spheres, spheroids and side-drilled holes. Most defects can be located close to a planar back surface and the strip-like crack may in addition be surface-breaking. The defects are assumed to have smooth surfaces with the exception of the strip-like crack which is allowed to have a small roughness.
The probe in UTDefect can operate in pulse-echo, tandem or with a fixed transmitter and moving receiver. The probes are of contact type, but can have any mode type, angle, frequency, bandwidth and size. Focussed probes and arrays are possible.
UT Defect has been validated for internal and surface-breaking cracks by comparisons with experiments and other models. The program can be of real help in the development of testing procedures, in parametric and sensitivity studies and in such technical justifications that are used for qualifications of procedures.
References
1.Boström, A., Wirdelius, H., J. Acoust. Soc. Am., 1997, 97, 2836-2848.
2.Boström, A., Developments of UTDefect: rough cracks and probe arrays, SKI report, 1997.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com
| NDTnet |