Nonlinear Elastic Wave NDE II. Nonlinear Wave Modulation Spectroscopy and Nonlinear Time Reversed Acoustics

2005 ◽  
Author(s):  
A. M. Sutin
Keyword(s):  
Elastic Wave ◽  
Nonlinear Wave ◽  
Modulation Spectroscopy ◽  
Wave Modulation ◽  
Nonlinear Elastic ◽  
Nonlinear Elastic Wave

Wave Motion of a Nonlinear Elastic Bar Subjected to Axial Excitation

2004 ◽  
Author(s):  
Liming Dai ◽  
Qiang Han
Keyword(s):  
Wave Propagation ◽  
Solitary Wave ◽  
Elastic Wave ◽  
Nonlinear Wave ◽  
Wave Motion ◽  
Initial Conditions ◽  
System Parameters ◽  
Elastic Bar ◽  
Nonlinear Elastic ◽  
Nonlinear Elastic Wave

This research intends to investigate the wave motion in a nonlinear elastic bar with large deflection subjected to an axial external exertion. A nonlinear elastic constitutive relation governs the material of the bar. General form of the nonlinear wave equations governing the wave motion in the bar is derived. With a modified complete approximate method, the asymptotic solution of solitary wave is developed for theoretical and numerical analyses of the wave motion. Various initial conditions and system parameters are considered for investigating the shape and propagation of the nonlinear elastic wave. With the governing equation of the wave motion of the bar and the solution developed, the characteristics of the nonlinear elastic wave of the bar are analyzed theoretically and numerically. Properties of the wave propagation and the effects of the system parameters of the bar and the influences of the initial conditions to the characteristics of the wave motion are investigated in details. Based on the theoretical analysis as well as the numerical simulations, it is found that the nonlinearity of the elastic bar may cause solitary wave in the bar. The velocity of the solitary wave propagating in the bar is related to the initial condition of the wave motion. This exhibits an obvious different characteristic between the nonlinear wave and that of the linear wave of an elastic bar. It is also found in the research that the solitary wave is a pulse wave with stable propagation. If the stability of the wave propagation is destroyed, the solitary wave will no longer exist. The results of the present research may provide guidelines for the wave motion analysis of nonlinear elastic solid elements.

scholarly journals Broadband nonlinear elastic wave modulation spectroscopy for damage detection in composites

2021 ◽  
pp. 147592172110025
Author(s):  
Joost Segers ◽  
Saeid Hedayatrasa ◽  
Gaétan Poelman ◽  
Wim Van Paepegem ◽  
Mathias Kersemans
Keyword(s):  
Carbon Fiber ◽  
Elastic Wave ◽  
Damage Detection ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Wave Modulation ◽  
Reinforced Polymer ◽  
Nonlinear Components ◽  
Nonlinear Elastic ◽  
Nonlinear Elastic Wave

A non-destructive testing procedure is proposed for damage detection in composites using full wavefield measurement obtained using a scanning laser Doppler vibrometer. Vibrations are excited using two low-power piezoelectric actuators leading to nonlinear elastic wave modulation at the defect. One actuator is supplied with a broadband chirp signal and the other actuator is supplied with a single-frequency sine signal. First, a time–frequency filtering method is proposed to extract specific nonlinear components of interest (e.g. second higher harmonic and first modulation sideband) without the need for multiple excitation sequences. Next, damage maps are constructed using broadband bandpower calculation of the filtered nonlinear components. It is demonstrated that the modulation sidebands provide an exclusive imaging of defect nonlinearity, and are not affected by potential source nonlinearity. The proposed damage map construction procedure is applied for various carbon fiber reinforced polymer test specimens with different damage features: (1) coupon with quasi-static indentation damage, (2) coupon with artificial delaminations, (3) bicycle frame with impact damage, and (4) stiffened aircraft panel with partially debonded stiffener. The obtained results indicate the high performance of the developed procedure for detection of various defect types in curved and/or stiffened carbon fiber reinforced polymer components.

Detection of structural damage of aluminum alloy 6082 using elastic wave modulation spectroscopy

2008 ◽  
Vol 41 (7) ◽  
pp. 554-563 ◽  
Author(s):  
Ladislav Straka ◽  
Yuriy Yagodzinskyy ◽  
Michal Landa ◽  
Hannu Hänninen
Keyword(s):  
Aluminum Alloy ◽  
Elastic Wave ◽  
Structural Damage ◽  
Modulation Spectroscopy ◽  
Wave Modulation

Micro-damage diagnostics using nonlinear elastic wave spectroscopy (NEWS)

2001 ◽  
Vol 34 (4) ◽  
pp. 239-248 ◽  
Author(s):  
Koen E-A. Van Den Abeele ◽  
Alexander Sutin ◽  
Jan Carmeliet ◽  
Paul A. Johnson
Keyword(s):  
Elastic Wave ◽  
Damage Diagnostics ◽  
Nonlinear Elastic ◽  
Nonlinear Elastic Wave
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