Stability and failure analyses of delaminated composite plates subjected to localized heating

Abstract

A layerwise B-spline finite element formulation is used to study the stability and first-ply failure of composite plates with embedded delaminations and subjected to localized thermal heating over the plate surface with uniform temperature rise through its thickness. The step functions are used to represent jump discontinuities in displacement fields at the zone of delamination between layers of composite plates. As the applied thermal loading is nonuniform, in the first step the prebuckling stress distribution within the plate is evaluated by solving the thermoelasticity problem. Subsequently, thermal buckling temperature is computed using the plate prebuckling stress distribution. Postbuckling response of the plate is obtained considering the von Kármán type geometric nonlinearity. In the delaminated region, virtual springs are added to prevent interpenetration of lower and upper sublaminates. The localized thermal load at which the first-ply failure of the lamina occurs has been detected by Tsai-Wu quadratic interaction criterion. The effects of the area of heating region, delamination size and its position in the thickness direction and plate boundary condition on the composite plate critical buckling temperature and on first-ply failure load are reported. The present model can capture global, local and combined global–local buckling mode shapes.