SPMS 2018

Session

Acoustic emission

Jun 19, 2018, 2:00 PM

Sokol Dobřichovice

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,)

34. Time Reversal Localization of Continuous Acoustic Emission Sources

Dr Zdeněk Převorovský (Institute of Thermomechanics CAS, Prague, Czech Republic,)

6/19/18, 2:00 PM

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...

9. Preisach-Mayergoyz space in elasticity and damage assessment of hysteretic materials

Colette Kožená (Department of Mathematics, FNSPE Czech Technical University in Prague)

6/19/18, 2:30 PM

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...

33. Noninvasive testing of human skin properties in-vivo

Julie Kuklewicz (INSA Centre Val de Loire, Blois, France)

6/19/18, 2:45 PM

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...

11. Spectral analysis of rifle barrel harmonics

Milan Chlada (Institute of Thermomechanics CAS, Prague, Czech Republic,)

6/19/18, 3:30 PM

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...

17. Geodesic optimization and acoustic emission localization maps processing

Petr Gális (Department of Mathematics, FNSPE Czech Technical University in Prague)

6/19/18, 3:55 PM

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...

39. Classification of Acoustic Emission Signals and Application of Phi-Divergence in the Field of Non-Destructive Testing

Zuzana Dvořáková (Institute of Thermomechanics CAS, Prague, Czech Republic,)

6/19/18, 4:15 PM

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...