Progressive Failure Analysis of UD-Fabric Hybrid Laminated Composite Joints Considering Material Nonlinearity

재료비선형을 고려한 일방향-평직 혼합 적층 복합재 체결부의 점진적 파손해석

A finite element method based on the two-dimensional progressive failure analysis considering material nonlinearity is presented for characterizing the strength and failure of the unidirectional-fabric hybrid laminated composite joints under pin loading. The 8-node laminated shell element is incorporated in the updated Lagrangian formulation. Failure criteria including the Maximum Stress and Tsai-Wu are used in conjunction with the complete unloading stiffness degradation method. For the verification, joint tests are conducted for the specimens with two different ply-number ratios of UD composite to fabric composite. Although there are some differences depending on ply-number ratios, the finite element model using the maximum stress criterion considering nonlinear material behavior predicts the failure strength best.