Finite Element Analysis on Microscopic Fracture of FRP at Crack Tip under Mode II Loading

Abstract

The finite element analysis was carried on in order to clarify the microscopic fracture mechanism of the matrix resin layer of FRP at the crack tip under the mode II loading. The analysis revealed the fracture process as follows : First, the microcrack initiated at the main crack tip due to the principal stress. Subsequent microcracks occurred one after another at even intervals with the increasing shear loading. Then, the delamination of the interface between fibers and the matrix resin layer initiated around the last microcrack due to the shear stress. Finally, the connection of microcracks occurred from the last microcrack to the main crack tip. The effect of the thickness of the matrix resin layer on the interval of microcracks was also investigated. The interval of microcracks increased in proportion to the increase of the thickness of the matrix resin layer.