Papers by Author: Ji Young Choi

Abstract: A two-dimensional progressive failure analysis is conducted to predict the failure loads and modes of carbon-epoxy composite joints under pin-loading. An eight-node laminated shell element is used for the finite element modeling. Post-failure stiffness is evaluated based on the complete unloading model combined with various failure criteria. The comparison of finite element and experimental results shows that the finite element analysis based on the combined maximum stress and Yamada-Sun criteria most accurately predicts the failure loads of the composite laminated joints.

Abstract: Progressive failure analysis based on the complete unloading method was conducted to investigate the crippling failure of carbon/epoxy composite stiffeners under axial compression. A modified arc-length algorithm was incorporated into a nonlinear finite element method to trace the equilibrium path after local buckling. For the validation of the finite element method, several carbon/epoxy Z-section stiffeners were tested in compression. The finite element results on the buckling and crippling stresses showed good agreement with the experimental results.