Elastoplastic Behaviour of Multidirectional Porous Functionally Graded Panels: A Nonlinear FEM Approach

This study presents the elastoplastic behavior of multidirectional (1D/2D/3D) functionally graded (FG) composite panels including even and uneven porosities. The equivalent elastic properties are evaluated using modified multi-variable power-law functions, whereas the Tamura-Tomota-Ozawa (TTO) model is employed for elastoplastic properties. To capture geometrical nonlinearity, first-order shear deformation theory-based von Karman strain kinematics is utilized; however, von Mises yield criterion using bilinear isotropic strain hardening is considered for material nonlinearity with an elastic ceramic phase and an elastoplastic metal phase. The governing equation is obtained through the variational principle and solved via 2D isoparametric finite element approximations in conjunction with the Newton-Raphson iterative technique. The accuracy of the present model is demonstrated by comparing with the available reported results. Additionally, the load-deflection responses of multidirectional porous FG composite panels are presented for various sets of conditions and discussed in detail.

Automated summary

This study investigates the elastoplastic behavior of multidirectional functionally graded composite panels with different porosities. Elastic properties are determined using modified multi-variable power-law functions, while the Tamura-Tomota-Ozawa (TTO) model is used for elastoplastic properties. To account for geometrical nonlinearity, a first-order shear deformation theory-based von Karman strain kinematics is employed, and von Mises yield criterion with bilinear isotropic strain hardening is used for material nonlinearity. The governing equation is obtained through the variational principle and solved using 2D isoparametric finite element approximations and the Newton-Raphson iterative technique. The accuracy of the model is validated by comparing with reported results, and the load-deflection responses of the composite panels are presented and discussed.