Effective properties of centro-symmetric micropolar composites with non-uniform imperfect contact conditions

Abstract

In this work, the homogenization theory is addressed within the framework of three-dimensional linear micropolar composite materials with centro-symmetric constituents and non-uniform imperfect interface conditions. The imperfect contact conditions are modeled like a generalization of the spring model, where tractions and coupled stresses are continuous, but displacements and microrotations are discontinuous across the interface. The jumps in displacement and microrotation components are proportional to the interface traction and coupled stress components in terms of a partition of different spring-factor-type interface parameters, respectively. The two-scale asymptotic homogenization method (AHM) is developed, through series expansions for displacements and micro-rotations, to find the analytical statement of the local problems on the periodic cell and the corresponding effective coefficients. In particular, centro-symmetric multi-laminated micropolar composites with non-uniform imperfect contact conditions are studied, and their corresponding effective properties are explicitly declared. Numerical results show the effects of the interface partition lengths, the non-uniform imperfection values, and the constituent’s fraction volumes on the effective properties of centro-symmetric bi-laminated composite with isotropic constituent materials. We also analyze and discuss the effective behaviors illustrated in the results. In general, the effective properties are always affected by a non-uniform imperfect interface, and they are bounded between those achieved when the contact conditions are perfect and imperfect uniform. The reported formulas and data may be helpful as benchmarks for checking other experimental and numerical results.