Description of the mechanical behaviour of micropolar adhesives

The paper describes the mechanical behavior of two solids—the adherends—adhesively bonded by a thin elastic adhesive considered as a polar material when the parameter associated to the thinness of the adhesive goes to 0. The adherends are considered as elastic nonpolar materials. The limit analysis for a thin adhesive is performed using first an asymptotic expansion of the solution, based on a mixed variational formulation of the equilibrium of the three bodies. The first- and second-order solutions are such that the adhesive behaves as a material surface. The implication of the additional rotational degrees of freedom on the kinematics of the adhesive is then studied. In the second part of the paper, the convergence of the solution of the three-dimensional problem to the limit solution is obtained, using a variational formulation of the equilibrium of the three body system and an epi-convergence argument.