变厚度复合材料层合曲板大挠度性能研究OA

This study systematically investigates the mechanical response and failure mechanisms of variable-thickness composite laminates under large deflection through a combined experimental and simulation approach.First,laminate specimens with thickness gradients are designed,and cantilever bending tests are conducted to obtain strain distributions,ultimate bending angles,and failure morphologies.Second,a global-submodel collaborative analysis method is proposed,employing shell element models to efficiently simulate overall deformations.Solid submodels combined with the 3D Hashin failure criterion and cohesive elements are used to accurately characterize the damage evolution process in the variable-thickness transition regions.The results indicate that initial delamination occurrs at a bending angle of 53°,and complete failure due to fiber compression failure and delamination propagation occurrs at 65°.Interlaminar normal and shear stress concentrations in the variable-thickness transition regions are identified as the dominant factors for delamination initiation,while fiber compression failure is driven by the coupling of axial compressive stress and in-plane stresses.The established model demonstrates excellent agreement with experimental results in terms of strain distribution,failure modes,and critical angle,providing a reliable theoretical basis for the optimal design and performance evaluation of variable-thickness composite structures.