Configurations involving echoes created by the specimen geometry occur frequently. It is also important to be confident in CIVA models’ capabilities to correctly reproduce them. Those geometrical echoes include echoes produced by the specimen surface and multiple rebounds on the specimen backwall, whose amplitude decreases versus time, depending on attenuation features of the specimen material.
Since CIVA 11, a new model for the calculation of geometrical echoes has been developed, the specular model, in order to improve upon the predictions of the Kirchhoff model used in CIVA 10. This study aims also to experimentally characterize results obtained with this new specular model, and to confirm the improvement of the geometrical echoes calculation with the specular model compared to the Kirchhoff model.
Comparisons between measures and simulations have been classed into three parts: the surface echo only, then the backwall echo only and finally the “complete” geometrical echoes, that means the multiple echoes.