| Description |
Description: This program is based on the Ph.D. thesis[1]: "LAMB: a SIMULATION TOOL for AIR-COUPLED LAMB WAVE BASED ULTRASONIC NDE SYSTEMS" from The Polytechnic University of Catalonia (UPC), Department of Electronic Engineering (EEL) 2010.
The software simulates the behaviour of an entire air-coupled ultrasonic Non-Destructive Evaluation (NDE) system based on 1D linear array transducers.
It is composed on three sections that allow the calculation of the pressure signals in air (plate's excitation & radiation zones) and the Lamb wave vibrations (vertical displacements) on the surface an infinite isotropic ideal single plate.
The acoustic field engine of the toolbox is the FIRST (Field Impulse Response Software) program based on the ImpulseResponse Method (IRM) for rectangular apertures [2]. This routine is capable of simulating plane and cylindrical concave 1D arrays. Bi-dimensional apertures on emission and reception are not yet implemented.
The plate propagation module is integrated by: 1) the Lamb wave dispersion data calculator (routine: 'main_LAMB_GMM_0v1.m' separate available from the toolbox) and a discrete generalization of the Time Harmonic Solution[3] for finite number 'num_p' of circular excitation 'regions' on the laminate surface.
In the routine 'f_THS_compute' there is the possibility to change the default THS core calculation method to other two alternative approaches: 1) Mit model[4,5] or 2) Achenbach 'punctual' model[6,7].
References:
[1] Prego-Borges, J.L. “Lamb: a simulation tool for air-coupled Lamb wave based ultrasonic NDE systems”. In Proceedings of the 1st. Barcelona Forum on Ph.D. Research in Electronic Engineering Nº2 (2010) Universitat Politècnica de Catalunya.
[2] San Emeterio J.L. and Ullate L. "Diffraction impulse response of rectangular transducers". J. Acoust. Soc. Am. 92(2) (August 1992).
[3] Ditri J.J., Pilarski A., Pavlakovic B. and Rose J.L. "Generation of guided waves in a plate by axisymmetric normal surface loading". Review of Progress in Quantitative NDE 13 (1994), 133–140. Ed. by D.O. Thomson and D.E. Chimenti, Plenum Press.
[4] Shi, Y. Analisys of optimim Lamb wave tuning. PhD thesis, Department of Civil and Enviromental Engineering, Massachusetts Institute of Technology, Feb. 2002.
[5] Shi, Y., Wooh, S.-C., and Orwat, M. Laser-ultrasonic generation of lamb waves in the reaction force range. Elsevier,
Ultrasonics 41 (August 2003), 623–633.
[6] Achenbach, J.D., and Xu, Y. "Use of elastodynamic reciprocity to analyze point-load generated axisymmetric waves in a plate". Elsevier, Wave Motion 30 (September 1998), 57–67.
[7] Achenbach, J. D., and Xu, Y. Wave motion in an isotropic elastic layer generated by a time-harmonic point load of arbitrary direction. J. Acoust. Soc. Am. 106, 1 (July 1999), 83–90.
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