Impulsive responses of composite spherical shells reinforced by graphene platelets with spiderweb stiffeners and porous core

Abstract

This study examines the nonlinear impulsive responses of functionally graded graphene platelet-reinforced composite (FG-GPLRC) shallow spherical shells and circular plates with spiderweb stiffeners and porous cores. Graphene platelets are distributed in the coatings and stiffeners according to various grading patterns, while the core is modeled as a porous medium. An improved smeared stiffener technique is developed to account for the stiffness contribution of the meridian-parallel spiderweb configuration, including the stiffness merging effect near the central region. The governing equations are formulated based on Donnell shell theory and von Kármán geometric nonlinearity using the energy method. The resulting nonlinear motion equations are solved via the Runge–Kutta method under triangular (blast-type) and rectangular (step-type) impulsive loads. Parametric studies reveal that spiderweb stiffeners markedly increase the fundamental frequency and significantly reduce transient deflections. The graphene mass fraction, distribution pattern, porosity coefficient, and damping also play important roles in tailoring dynamic behavior. The proposed framework provides an efficient analytical tool for designing advanced FG-GPLRC structures under impulsive loading conditions.