Comprehensive Transverse Shear Stress Analysis for FG-GRC Sandwich Plates Based on a Refined Higher-Order Zigzag Theory

Interlaminar transverse shear stress plays a critical role in delamination and damage of laminated composite plates. As graphene platelets (GPLs) are piecewise distributed along the thickness to present gradient properties, fully assessing maximum values of transverse shear stress for functionally graded graphene-reinforced composite (FG-GRC) structures is necessary. This paper conducts a comprehensive analysis of transverse shear stress for FG-GRC sandwich plates. Nine different distribution patterns of GPLs covering three core types including softcore, hardcore and FG core are considered for the first time. To guarantee analysis accuracy of transverse shear stresses, a refined higher-order zigzag theory related with material heterogeneity in the framework of refined plate theory is presented. On this basis, governing equations for static analysis of GRC plates are formulated by employing the minimum potential energy principle, and analytical solutions are presented by the Navier method. Numerical cases well validate the accuracy of this model in predicting transverse shear stress fields by constitutive relations. Furthermore, numerical analysis and discussion demonstrate that the FG-GRC sandwich plate with GPL distribution pattern [Formula: see text] shows the highest bending stiffness in most cases and the smallest value of maximum transverse shear stresses in GRC layers within full range of matrix modulus, core thickness, graphene weight ratio and side-to-thickness ratio.