Investigation on mode III interlaminar fracture of glass/epoxy laminates using a modified split cantilever beam test

•The mode III interlaminar fracture of composite laminates was investigated.•Influence of fiber volume fraction on the critical mode-III strain energy release rate.•Three dimensional finite element analyses based on virtual crack closure technique and cohesive elements.•Crack length dependency of critical mode-III strain energy release rate. The mode III interlaminar fracture of composite laminates was investigated with the modified split cantilever beam test. Specimens were made of E-glass/epoxy laminates with 30%, 46% and 55% of fiber volume fraction. The suitability of the current test was validated by virtual crack closure and mixed-mode cohesive zone model techniques. It was observed that more than 94% of total strain energy release rate was allocated to mode-III fracture toughness. It was found that measured GIIIC corresponding to onset of crack propagation and also its crack length dependency, substantially increased with decreasing fiber volume fraction of specimens.