Global buckling analysis of composite honeycomb sandwich plate with negative Poisson's ratio (CHSP-NPR) using variational asymptotic equivalent model

In present work, the variational asymptotic method is extended to study the bucking of composite honeycomb sandwich plate with negative Poisson?s ratio (CHSP-NPR), which is easily buckle under compressive loads or bending moments and may lead to catastrophic failure. For global bucking with small local rotations, the 3D geometrical nonlinear problem is decoupled into linear constitutive modeling using unit cell and geometrical nonlinear problem defined over the 2D equivalent plate model (2D-EPM). Results using 2D-EPM in global buckling analysis are compared with 3D-FEM results to evaluate the accuracy and efficiency of the present model, and parametric studies are carried out to reveal the relative influence of selective parameters on buckling behavior of CHSP-NPR. The results show the increase of the proportion of honeycomb core and the decrease of fiber volume fraction of face sheet may increase the negative Poisson?s ratio and weaken the buckling resistance of CHSP-NPR, but the buckling loads of CHSP-NPR are larger than those of conventional honeycomb sandwich plate under the same conditions.