Buckling analysis of hybrid fiber‐reinforced composite sandwich panels with varying numbers of polyurethane cores

Abstract Hybrid fiber‐reinforced composite sandwich panels with multi‐layer polyurethane cores are widely applied in aerospace, automotive, construction, and shipbuilding industries. This study aims to investigate the buckling performance of composite structures with varying numbers of polyurethane cores. To achieve this, the buckling loads of these structures are determined using an energy method, microscopic mechanics method, and the first‐order zigzag kinematic model. The accuracy of the equation employed in the algorithm is validated using the finite element method. Additionally, we conduct a parametric analysis to examine the influence of various parameters on the buckling performance of the structures. The results indicate that an effective strategy for improving the critical buckling loads of the hybrid fiber‐reinforced composite sandwich plate involves strategically placing fibers and matrix materials with higher elastic modulus on the skin layer. Moreover, the critical buckling load is notably influenced by the number and positioning of polyurethane layers, as well as the fiber content. Highlights An analytical model is established to predict the buckling behavior. The correctness of the model was verified using the finite element method. Effects of structural parameters on buckling performance were investigated.