Isogeometric analysis for postbuckling of sandwich cylindrical shell panels with graphene platelet reinforced functionally graded porous core

The proposed work investigates for the first time the postbuckling behavior of sandwich cylindrical shell panels with two metallic face layers and a graphene platelet (GPL) reinforced functionally graded porous (FGP) core subjected to central point loads, uniform and non-uniform pressure loadings. Based on a general higher-order shear deformation shell theory and the von Karman large deflection assumption, the discrete equilibrium equations of the sandwich cylindrical panels are established by the principle of virtual work. The NURBS (nonuniform rational B-spline) based isogeometric analysis (IGA) in conjunction with the modified arc-length method of Crisfield are utilized synthetically to acquire nonlinear load-deflection responses for the panels numerically and both snap-through and snap-back types of instability are captured. Several benchmarks are carried out to verify accuracy and reliability of IGA and arc-length method in present formulation. Parametric studies are performed to demonstrate the influences of weight fraction of the graphene platelet, porosity distribution, porosity coefficient and thickness of the sandwich core on the nonlinear load-deflection responses of the sandwich cylindrical panels. Some complex load-deflection curves of the FGP-GPL cylindrical panels may be useful for future references.

Automated summary

This study investigates the postbuckling behavior of sandwich cylindrical shell panels with a graphene platelet reinforced functionally graded porous core under various loads for the first time. Utilizing a combination of NURBS-based isogeometric analysis and the modified arc-length method, the study demonstrates nonlinear load-deflection responses and captures different types of instability. Parametric studies show the influences of various factors on the load-deflection behavior of the panels.