TY - GEN
T1 - Measuring acoustic nonlinearity by collinear mixing waves
AU - Liu, M.
AU - Tang, G.
AU - Jacobs, L. J.
AU - Qu, J.
PY - 2011
Y1 - 2011
N2 - It is well known that the acoustic nonlinearity parameter β is correlated to fatigue damage in metallic materials. Various methods have been developed to measure β. One of the most often used methods is the harmonic generation technique, in which β is obtained by measuring the magnitude of the second order harmonic waves. An inherent weakness of this method is the difficulty in distinguishing material nonlinearity from the nonlinearity of the measurement system. In this paper, we demonstrate the possibility of using collinear mixing waves to measure β. The wave mixing method is based on the interaction between two incident waves in a nonlinear medium. Under certain conditions, such interactions generate a third wave of different frequency. This generated third wave is also called resonant wave, because its amplitude is unbounded if the medium has no attenuation. Such resonant waves are less sensitive to the nonlinearity of the measurement system, and have the potential to identify the source location of the nonlinearity. In this work, we used a longitudinal wave and a shear wave as the incident waves. The resonant shear wave is measured experimentally on samples made of aluminum and steel, respectively. Numerical simulations of the tests were also performed using a finite difference method.
AB - It is well known that the acoustic nonlinearity parameter β is correlated to fatigue damage in metallic materials. Various methods have been developed to measure β. One of the most often used methods is the harmonic generation technique, in which β is obtained by measuring the magnitude of the second order harmonic waves. An inherent weakness of this method is the difficulty in distinguishing material nonlinearity from the nonlinearity of the measurement system. In this paper, we demonstrate the possibility of using collinear mixing waves to measure β. The wave mixing method is based on the interaction between two incident waves in a nonlinear medium. Under certain conditions, such interactions generate a third wave of different frequency. This generated third wave is also called resonant wave, because its amplitude is unbounded if the medium has no attenuation. Such resonant waves are less sensitive to the nonlinearity of the measurement system, and have the potential to identify the source location of the nonlinearity. In this work, we used a longitudinal wave and a shear wave as the incident waves. The resonant shear wave is measured experimentally on samples made of aluminum and steel, respectively. Numerical simulations of the tests were also performed using a finite difference method.
KW - Mixing Waves
KW - NDE
KW - Nonlinear Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=80555145265&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80555145265&partnerID=8YFLogxK
U2 - 10.1063/1.3591871
DO - 10.1063/1.3591871
M3 - Conference contribution
AN - SCOPUS:80555145265
SN - 9780735408883
T3 - AIP Conference Proceedings
SP - 322
EP - 329
BT - Review of Progress in Quantitative Nondestructive Evaluation
T2 - 37th Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE
Y2 - 18 July 2010 through 23 July 2010
ER -