Inter-laminar fracture is the key disadvantage of laminated fiber reinforced composites, precisely delamination. Delamination is a commonly observed failure due to the composite construction nature. Preparing composite structures involve various techniques of manufacturing. Commonly, most popular method of composite manufacturing is layer by layer lay-up method. Interacting portion between the two layers is obviously not reinforced with fibers due to which delamination or inter-laminar fracture occurs. Material property that denotes resistance to delamination is strain energy release rate (GC). Primary objective of this paper is to find the critical strain energy release rate or interlaminar fracture toughness which is produced due to the sliding mode of fracture in composite laminate. Fracture toughness (GIIC) for mode II crack expansion is found for a glass fiber reinforced polymer composite with 00 orientation unidirectional fibers. 40%, 50% and 60% volumes of fiber are compared with each other to find the best volume fraction at which the resistance to crack growth GIIC is maximum. Compliance Calibration Method is used for the experimental investigation. Investigation is carried on End Notched Flexure specimen prepared from E-glass fiber and epoxy as per ASTM D7905 in hand layup method. Numerical analysis was done using virtual crack closure technique (VCCT). Experimental results obtained are again correlated with numerical results.


Glass fiber reinforced polymer, Inter-laminar Fracture, Strain Energy Release Rate, Fracture Toughness