Postbuckling Isogeometric Analysis of Functionally Graded Carbon Nanotube-reinforced Composite Shells Under Combined Loading

In this work, the shell formulation for postbuckling analysis of functionally graded carbon nanotube-reinforced composite shells based on isogeometric analysis and first-order shear deformation shell theory (FSDT) is proposed. The nonlinearity of shells is formed in the Total Lagrangian approach considering the von Karman assumption. The nonlinear equation is numerically solved by using a modified Riks method. In the present formulation, the effective material properties are estimated via the rule of mixture. Exact geometries of shells are modeled based on the advantage of isogeometric analysis. Several examples are given to confirm the high reliability of the proposed formulation.