Nonlinear stability of axially compressed couple stress-based composite micropanels reinforced with random checkerboard nanofillers

Abstract

In this investigation, by matching the moving Kriging meshfree formulations with the third-order shear flexible shell model together with the modified couple stress continuity, the size-dependent nonlinear stability characteristics of micropanels subjected to axial compression are analyzed. The random checkerboard model is employed for the micropanels made of graphene nanoplatelet random-reinforced composites. The associated material characteristics are evaluated via a probabilistic-based micromechanical scheme. Afterwards, proper meshfree functions are implemented to enforce the essential boundary conditions at the considered nodding system accurately. It is shown that the stiffening character of the couple stress size dependency coming from the rotation gradient tensor causes to rise the nonlinear critical stability load and the associated critical shortening of random reinforced composite micropanels. Moreover, for a specific value of the graphene nanofillers volume fraction, by reducing the length to width aspect ratio of them, the role of rotation gradient size dependency in the both critical stability load and critical shortening of an axially compressed random checkerboard reinforced composite micropanel becomes somehow more significant.