Interface Laws for Multi-physic Composites

The paper describes the mechanical behavior of a composite constituted by two solids, bonded by a thin adhesive layer in a general multi-physic framework, by employing the asymptotic expansion technique. After defining a small parameter \(\varepsilon \), which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize three different limit models and their associated limit problems: the soft interface model, in which the constitutive coefficients depend linearly on \(\varepsilon \); the hard interface model, in which the constitutive properties are independent of \(\varepsilon \); the rigid interface model, in which they depend on \(\frac{1}{\varepsilon }\). The asymptotic expansion method is reviewed by taking into account the effect of higher order terms and by defining a general multi-physic interface law which comprises the above aforementioned models. Moreover, the FEM implementation of the transmission model is presented through a numerical example.