Electromechanical properties of architected periodic multifunctional foams and composites

Understanding the mechanical and piezoelectric properties of the architected periodic multifunctional foams and composites are of great interest when used in structural applications. Therefore, there is a need to explore and analyze different designs of piezoelectric foam, metamaterials and composites with tunable properties. Current analytical models cannot be readily applied to compute electromechanical characteristics of architected periodic piezoelectric foams and composites exhibiting elastic anisotropy and piezoelectric activity. This study presents a micromechanical modeling and finite-element based computational homogenization framework to compute the electromechanical properties of architected periodic piezoelectric foam, metamaterials and composites. The intrinsic symmetry of architected periodic foams and composites was utilized and simplified mixed boundary conditions (BCs) equivalent to periodic boundary conditions (PBCs) were recognized. As an example, 3D finite element models of the 3-0-type closed foam piezoelectric structures with spherical porosity were developed and their effective elastic, piezoelectric and dielectric properties was completely characterized. We investigate the effect of porosity volume fraction on the suitability of 3-0-type closed foam piezoelectric structures in specific engineering applications such as hydrophones. Figures of merit such as hydrostatic strain coefficient (d_h ), the hydrostatic figure of merit (d_h.g_h ), the acoustic impedance (Z ), and electromechanical thickness model coupling factor (^k_t ) are computed. Results showed that 3‐0 type porous piezoelectric material exhibited an enhanced response as compared to their bulk constituent. The FE results from the proposed framework found to be in good agreement with the FE results, based on the PBCs, available in the literature. Numerical results also showed that the excellent piezoelectric properties can be obtained and porous piezoelectric materials can exhibit unique combination of properties (low impedance and more sensitivity).