Fracture Behaviour of Cross-Ply Laminates with Interlaminar Delamination

摘要

Delamination in Fibre Reinforced Plastic (FRP) laminates occurs either due to manufacturing defects or due to inter-laminar failure during loading. Such situation cannot be handled through the concepts of solid mechanics and a need arises to extend the analysis to predict the fracture parameters to analyse such structures. The objective of the present investigation is to estimate the Strain Energy Release Rate (G) in a four layered cross-ply laminate under cylindrical bending having delamination at the interfaces throughout the length of the plate parallel to the supporting edges. Virtual Crack Closure Technique (VCCT) in combination with Finite Element Method (FEM) is used to determine the value of 'G'. Three dimensional finite element models are generated and validated in ANSYS software and further extended for obtaining Energy Release Rate. Variation of 'G' with respect to the crack length for symmetric and anti-symmetric arrangement of layers under transverse pressure load is studied. It is observed that 'G' increases with increase in crack length and its magnitude varies with respect to the stacking sequence of the laminate.