Delamination toughening of composite laminates using weakening or toughening interlaminar patches to initiate multiple delaminations: A numerical study

A numerical study on toughening laminated composite materials against delamination by initiating multiple interlaminar cracks is presented. Different configurations of interface and weakening patches, that modify the properties at selected locations, are investigated as a way to trigger delaminations. Both patches can be configured toughen material The initiation delaminations increase in toughness depend strengths patches. main mechanisms behind for both cases An adaptive refinement method implemented within Matlab Finite Element Analysis code models interfaces laminate with cohesive elements used analyses. framework allows efficient analysis very fine meshes wake crack tips. discussion overall performance concept, parameters affecting results, i.e. length or distance substrate between affected interfaces, material’s mechanical properties, carried out. results presented paper show effect achieved using onset • Multiple structures. initiated weakening/toughening Interface patch strength must modified initiation. critical energy release rate new onset. result higher dissipated fracture energy.