Efficient finite element framework for static and buckling analysis of variable angle tow composite plates using thickness stretching kinematic model

Variable Angle Tow (VAT) composites are advanced materials that enable spatial stiffness tailoring within the lamina through curvilinear fibre paths, in contrast to the conventional constant stiffness composites, which use straight fibre profiles. The analysis of such complex structures necessitates refined two-dimensional plate theories capable of accurately capturing their mechanical behaviour with optimal trade-off between accuracy and computational demand. This study presents static and buckling analysis of VAT composite plates using the Equivalent Single Layer (ESL)-based Higher Order Shear Deformation and Normal Theory (HOSNT12). The governing equations are solved using the finite element approach. A key novelty lies in the integration of HOSNT12 with the Gauss Point Change (GPC) strategy and its comparison with the Constant Stiffness Element (CSE) approach, including an investigation of varying Gauss point distributions. Unlike traditional ESL models, the proposed formulation captures thickness-stretching effects, making it well suited for moderately thick and thick composite plates. The study assesses the influence of fibre angle orientations on static and buckling behaviour in addition to the evaluation of the stress concentration around the central hole in VAT plates.