Mechanical and acoustical study of a structural bond: comparison theory/numerical simulations/experiment

To carry out numerical simulations able to describe the behavior of a structural bond during a mechanical test, it is common to use a theory of damage. This approach consists in modeling the bonded zone by a surface distribution of springs with or without mass. The elasto-plastic with damage model and the numerical simulations are carried out with a finite element code. The use of this model requires two types of data: the critical energies in modes I and II measured during mechanical tests and the stiffnesses of the springs. These ones cannot be identified by mechanical measurements and, in this paper we propose an ultrasonic method to measure them. The ultrasonic approach and its experimental validation are first presented. Then, the mechanical model is detailed. The whole identification strategy is applied on aluminum/epoxy/aluminum samples.