Conveners
Acoustic emission
- Václav Kůs (Department of Mathematics, FNSPE Czech Technical University in Prague)
Acoustic emission
- Zdeněk Převorovský (Institute of Thermomechanics CAS, Prague, Czech Republic,)
Time reversal (TR) processing of acoustic and ultrasonic signals is effective tool for complicated problems solution in NDT /E and structural health monitoring. TR enables space-time focusing of elastic wave and thereby relatively easy location and partial reconstruction of both burst and continuous acoustic emission (AE) sources. AE source location problems come up in situations with high...
Preisach-Mayergoyz model (PM model) of hysteresis can be used to evaluate the mechanical properties of hysteresis materials. Program called PM identifikator with it's main function, automatic identification of the PM space probability density within a class of distribution mixtures by means of optimization stochastic algorithms and $\phi$-divergence measures, is presented. An extension of...
Human skin is a complex stratified biomaterial with nonlinear viscoelastic mechanical
behavior. Its mechanical properties in-vivo are of great interest in dermatology, plastic
surgery and cosmetics. A special small skin loading device with embedded ultrasonic
probes is used for noninvasive in-vivo testing of the skin in NDT laboratory of the
Institute of Thermomechanics. It enables...
Standard approaches to spectral analysis of discrete signals as Fast Fourier Transform (FFT) can turn out insufficient due to their limited frequency resolution caused by improper sampling period or the length of measuring time interval. In such cases, it is needed to compute the power spectral density function estimate for frequencies not available in standard Fourier Basis as well. Similarly...
We furthermore extend numerical model of localization of acoustic emission (AE) sources on real complex solid bodies based on exact geodesic curves on 3D vessels composed of several parametrized surfaces. The numerical computations are provided via Finite difference, Newton–Raphson, and Fixed-point iteration methods applied to geodesic equations. To speed up computations, some technical...
The acoustic emission (AE) belongs among methods of nondestructive testing serving to investigate materials. One of the most important task is to clasify measured source of AE, because not only cracks and other damages produce AE, but also external forces and stress in the materials produce signals of AE. Our aim is to classify measured AE signals. We compare several classification methods as...
