ULTRASONIC SCATTERING ANALYSIS TO CHARACTERIZE NONLINEAR BEHAVIOR OF MATERIAL INTERFACES

Abstract The scattering problem of elastic waves by a three-dimensional inclusion with a nonlinear interface condition is solved. The nonlinear interface condition is represented by using a distribution of nonlinear springs inserted at the matrix-inclusion interface. The springs have perfect elastoplastic characteristics, while the inclusion and the surrounding matrix are linear at all times. Thus, the problem is reduced to the boundary-type dynamic nonlinear problem. A time-domain boundary integral equation method is applied to obtain numerically dynamic behaviors of the nonlinear interface. In numerical examples, a spherical inclusion subjected to an incident plane L-wave is considered. Results as functions of time are obtained for displacements and tractions at the nonlinear interface and the scattered far-field.