Characterisation of metal based composit through the excitation of non-linear resonant flexural modes

Sensitivity of nonlinear acoustic methods to the presence and the evolution of microdamage has been proven in various studies on a wide range of materials (composites, concrete, rocks, etc.). This sensitivity is due to the relationship existing between the elastic properties of the above-mentioned materials and the created strain during the passage of the acoustic disturbances. Single mode nonlinear resonance experiments were proposed to explain the decrease in resonance frequency as well as the quality factor as a function of the dynamic strain. Thereby, the hysteretic parameters corresponding to the elastic modulus as well as damping are determined for a single frequency. In this work we propose an experimental method to track global changes in hysteretic nonlinear elastic parameters as a function of frequency in the case of a metal matrix composite at intact as well as damaged states. © 2014 Lavoisier.