Multiscale structural analysis of thick sandwich structures using parametric HFGMC micromechanics and isogeometric plate formulation based on refined zigzag theory

This study presents a novel multiscale modeling strategy by combining the parametric high fidelity generalized method of cells (HFGMC) micromechanical model and isogeometric analysis (IGA) based on refined zigzag theory (RZT) for thick sandwich structures. Effective behavior of sandwich face sheets at the macro scale is defined by using constituent (fiber and matrix) properties in the HFGMC model, thereby eliminating the need for time-consuming and costly experiments. At the macro level, the RZT kinematics is utilized to define zigzag distributions of in-plane displacement along thickness coordinate, which can accurately model a thick laminate or a sandwich structure as a single layer regardless of its plies. Moreover, the IGA is leveraged to discretize geometry of the structure effectively with non-uniform rational B-splines (NURBS) basis functions, i.e., free of shear locking phenomena. Various test cases of thin/thick laminates with high heterogeneity and anisotropy are analyzed to demonstrate wide-range applicability of the present approach. Results of the proposed multiscale framework provide excellent distributions of in-plane displacements and stresses along the thickness directions of the laminates as compared to the three-dimensional reference solutions. Hence, computational efficiency, high accuracy, and low cost of the present method are revealed for sandwich structures.