Si-Chaib M., Djelouah H., Nour A.

This study deals with the propagation of ultrasonic waves propagating in homogeneous and isotropic metallic samples, submitted to axial elastic compression or traction stresses. In presence of an applied stress to a piece, received waveforms of an ultrasonic transducer undergo a change of position in comparison to a free stressed state. This phenomenon depends on the classic acoustoelasticity theory. For a material of known second and third elastic constants, defined volumique mass and a stress, we can determine the wave propagation velocity in stressed state. This velocity depends also of parameters consecutive to propagation and polarization directions of the wave and the considered applied stress. The construction of the theoretical stressed waveforms is obtained by measuring of longitudinal or transversal waveforms given by probed samples in free stressed state. The samples studied as propagation media are made of C 35 steel and AU 4G alloy, which have been kept for theirs homogeneity, acoustic and mechanical properties and theirs current utilization in mechanical construction of structures and machines. Taking into account the elastic deformation and stressed velocity of the transmitting wave, the calculus of the time variation of flight permits to simulate theoretical waveforms for each applied stress. To validate this method, an experiment is achieved for two above usual materials. These obtained results are partially in good agreement with the theory. This simulation method applied to isotropic elastic materials would open new perspectives in studying of composed mechanical solicitations.