Global/local approach using partial hybrid finite element analysis of stress fields in laminated composites with mid-plane delamination under bending

A global/local approach using partial hybrid elements is presented. to stud y the interlaminar stress distribution around delamination crack tills in c omposite laminates subjected to out-of-plane loading. The cracked composite laminate is modeled with three types of elements. 20-node three-dimensiona l sublaminate partial hybrid elements are used in the local region where th e stress gradients are expected to be sharp, 8-node degenerated partial hyb rid plate elements are used in the global region and 15-node transition ele ments are employed to connect the local and global regions. The results sho w that the global/local approach yields accurate solutions with much less a ctive degrees of freedom, less consumption of computer space and CPU time a s compared with the conventional displacement element. Experiments are perf ormed for cross-ply laminates with midplane delamination crack subjected to three-point bending. The predicted critical loads by finite element analys is based on both a strength-based criterion and a fracture mechanics approa ch are in good agreement with the experimental data.