FEM analysis on mixed-mode fracture of CSM-GRP

A FEM analysis for studying mixed-mode fracture problem of chopped strand mat glass fibre reinforced polyester laminate is presented. The analysis is formulated on the basis of 8-node quadrilateral isoparametric element. The collapsed triangular quarter-point singular elements were used for calculating stress intensity factors K_I and K_II.The crack propagation process was computed by implementing constraint release technique. Three different approaches to the solution of stress intensity factors K_I and K_II were compared. The effect of constraint condition imposed upon the displacement of the three collapsed nodes of the crack tip elements on the K_I and K_II results was evaluated. The mixed-mode critical stress intensity factors K_IC and K_IIC were estimated for CSM-GRP through the consideration of K_I and K_II calculated and the measured failure load and critical crack length in the experiment.