Laminated and sandwich plates are widely used in engineering applications due to their high strength-to-weight ratio. However, the presence of delamination can significantly affect their structural performance, particularly under bending loads. This study addresses the numerical homogenization of multilayer laminated and sandwich plates, incorporating the effects of compliance and a lack of integrity between layers, in particular, delamination. Previous research has described the homogenization process, but this study focuses on the impact of delamination on bending stiffness without affecting tensile stiffness.

We employed numerical homogenization techniques, incorporating interplay delamination or partial delamination to model these effects. The Finite Element Method (FEM) was utilized to simulate the behavior of delaminated plates, ensuring accurate boundary conditions through using periodic boundary conditions to capture the correct stiffness reductions. The analysis revealed that delamination leads to significant reductions in bending stiffness, while tensile stiffness remains largely unaffected. The correct implementation of periodic boundary conditions was crucial in accurately estimating stiffness reductions in delaminated plates.

This research highlights the importance of accurate boundary condition assumptions in numerical models for predicting the structural performance of partially delaminated multilayered and sandwich plates. The findings provide a basis for more reliable design and analysis of such structures, promoting better understanding and mitigation of the effects of delamination. This study underscores the potential of advanced numerical methods to enhance the analysis and design of complex laminated and sandwich structures, contributing to more resilient and efficient engineering solutions.