Low-Velocity Impact Analysis of Composite Plates using the Hashin 3D Criterion and Layer-Wise Models

Numerical simulations are an essential tool for predicting structural response under low-velocity impact and for damage evolution. The present work investigates the low-velocity impact (LVI) response of composite laminate plates by applying the Carrera Unified Formulation (CUF) for structural modelling combined with a fully three-dimensional (3D) Hashin failure criterion for damage evaluation. Previous studies have employed two-dimensional (2D) Hashin criteria, combined with cohesive zone models, to detect intralaminar and interlaminar damage. However, such approaches neglect out-of-plane stress components, which are critical in impact scenarios. The methodology discussed overcomes this limitation by adopting the 3D Hashin criterion within each ply, thereby allowing all six stress components to be included and providing a more accurate prediction of intralaminar damage and interlaminar delamination activation. The numerical model is developed within the CUF framework, using higher-order structural theories based on Lagrange polynomial expansions and a layer-wise representation through the laminate thickness. The results highlight the accuracy of the proposed approach and its computational cost advantages.