Wave propagation across a functionally graded interphase between soft and hard solids: Insight from a dynamic surface elasticity model

Joining soft to hard materials is a challenging problem in modern engineering applications. In order alleviate stress concentrations at the interface between with such mismatch mechanical properties, use of functionally graded interphases becoming more widespread design new generation engineered composite materials. However, current macroscale models that aim mimicking behavior complex systems generally fail incorporating impact microstructural details across interphase because computational burden. this paper we propose replace thin, but yet finite, by zero-thickness interface. This achieved means an original model developed framework surface elasticity, which accounts for both elastic and inertial actual interphase. The performance proposed equivalent evaluated context wave propagation, comparing calculated reflection coefficient obtained using different baseline models. Numerical results show our dynamic elasticity provides accurate approximation reference over broad frequency range. We demonstrate application modeling approach characterization tissue system tendon-to-bone interphase, fulfills task integrating tissues submillimeter-wide region.