This paper describes the mechanical behavior of two linear micropolar solids, bonded together by a thin plate-like layer, constituted of a linear micropolar material, determined by means of an asymptotic analysis. After defining a small parameter ε , which will tend to zero, associated with the thickness and the constitutive coefficients of the intermediate layer, we characterize two different limit models and their associated limit problems, the so-called weak and strong micropolar interface models, respectively. Moreover, we identify the nonclassical transmission conditions at the interface between the two three-dimensional bodies in terms of the increases in the stresses, coupling stresses, displacements, and microrotations. Finally, we prove that the solution of the original problems strongly converges toward the solution of the limit problems, as ε tends to zero.

This work proposes new interface conditions between the layers of a three-dimensional composite structure in the framework of coupled thermoelasticity. More precisely, the mechanical behavior of two linear isotropic thermoelastic solids, bonded together by a thin layer, constituted of a linear isotropic thermoelastic material, is studied by means of an asymptotic analysis. After defining a small parameter $\epsilon$, which tends to zero, associated with the thickness and constitutive coefficients of the intermediate layer, two different limit models and their associated limit problems, the so-called soft and hard thermoelastic interface models, are characterized. The asymptotic expansion method is reviewed by taking into account the effect of higher-order terms and defining a generalized thermoelastic interface law which comprises the above aforementioned models, as presented previously. A numerical example is presented to show the efficiency of the proposed methodology, based on a finite element approach developed previously.