Optimal design of delaminated composite plates for maximum buckling load

Due to laminated structure, manufacturing defects or external impact, composite materials often contain delaminations. The buckling behavior of laminated plates with elliptic delamination under uniaxial compressive loading is studied here. A optimal design method is used to find out the maximum buckling load, the design variables are the length of the plate, the width of the plate. The material was the long fiber composite. In analysis, the delaminated plate is modeled as a three dimensional problem. Four parameters, including the size of the delaminated region, the position of the delaminated region in the thickness direction, the width of the plate and the length of the plate; uniform mesh refinement around the delaminated region edge is enforced to overcome the singularity of the crack tip.