Porous materials are promising media for designing medical instruments, drug carriers, and bioimplants because of their excellent biocompatibility, ease of design, and large variation of elastic moduli. In this study, a computational strategy using the finite element method is developed to model the porous microstructures and to predict the relevant elastic moduli considering the actual characteristics of the micropores and their distributions. First, an element-based approach is presented to generate pores of different shapes and sizes according to the experimental observations. Then, a computational scheme to evaluate the effective moduli of macroscopically isotropic porous materials based on their micro-mechanics is introduced. Next, the accuracy of our approach is verified with the analytical solutions of the extreme bounds of the elastic isotropic moduli of a simplified model and with the experimental data available in the literature. Finally, the influence of the shape of pores and their distribution modes are assessed.

Piezomagnetic–piezoelectric composites can be applied to fabricate devices controlled both magnetically and electrically, and thus draw increasing attentions recently. The present paper aims to develop a computational methodology using the imperfect interface model to characterize the thin transition layers within such fibrous smart composites to quantitatively evaluate their influence on the magnetoelectric effects. First, the thin transition layers within a practical multi-phase smart composites are reformulated based on continuum mechanics as a general imperfect interfaces of null thickness, across which both the primary and secondary physical quantities suffer jumps. The strong and weak governing formulations are then derived for multi-coated fibrous composites containing general imperfect interfaces in arbitrary shapes, and a computational approach is further developed with the aid of the extended finite element method combined with the level set method to properly reconstruct the interfacial discontinuities induced by these thin transition layers. Hereafter, a benchmark problem involving a simplified general interfacial relation is designated, analytically solved, and applied to test the validity and robustness of the elaborated computational approach. Both the convergence analysis and physical evaluations highlight that the elaborated computational approach can robustly predict the physical quantities within both the primary and secondary fields, and accurately reproduce the interfacial discontinuities across each general imperfect interfaces. Eventually, the influence of thin transition layers are discussed in detail, and a few remarks are concluded.