Generalized interfaces via weighted averages for application to graded interphases at large deformations

Finite-thickness interphases between different constituents in heterogeneous materials are often replaced by a zero-thickness interface model. Commonly accepted models intuitively assume that the layer is situated exactly middle of its associated interphase. Furthermore, it has been reported literature this assumption necessary to guarantee balance angular momentum on interface. While coincides with mid-layer uniform interphase, we argue fails sufficiently capture behavior graded or inhomogeneous interphases. This contribution extends formulation general model account for arbitrary positions. The issue interfaces critically revisited. It proven position does not necessarily have coincide order satisfy balance. analysis here leads unique definition controversially discussed configuration. presented essentially based upon weighted average operator instead commonly classical operator. framework geometrically exact and suitable finite deformations. significance demonstrated via series examples where identified full resolution