Evaluating and Locating Plasticity Damage Using Collinear Mixing Waves

It is quite important for the detection and evaluation of material early degradation in order to ensure the durability and integrity of the key engineering components. The collinear wave mixing method is an effective and promising technique capable of detecting and localizing damage in materials. This research reports an investigation for evaluating and locating material plasticity damage in a metallic material by using collinear mixing wave technique. It is found that a third, resonant shear wave would be generated when the resonant condition of two collinear shear and longitudinal waves is satisfied. By controlling the triggering times of the signals that excite the primary waves, this wave mixing method is capable of scanning the cylindrical metallic specimens. Distributions of the amplitudes of resonant shear waves along the specimen can thus be obtained. Experimental study and numerical simulation show that amplitudes of the resonant shear waves are significantly increased at the plastic damage zone compared with that at the undamaged zone with same position on the specimen. It is demonstrated that this wave mixing technique has great potentials for identifying and evaluating the locations of the plastic damage zone in engineering.