Failure Analysis of Glass/Epoxy Composite Subjected to Different In-Plane Biaxial Loading Conditions

In recent years, several studies have been initiated to comprehend and predict the failure mechanisms of composite materials. The principal objective of these investigations is to develop a robust failure theory capable of accurately predicting the behavior of composite materials under various loading conditions. The absence of a reliable failure theory capable of effectively predicting composite failure under multi-axial loading makes this area of research particularly promising. Numerous investigations have been carried out to characterize the behavior of composite materials under diverse multi-axial loading conditions. These studies involve the generation of failure envelopes and subsequent comparisons with various failure theories. In this specific study, the traction/traction quadrant of the experimental failure envelope for a 0.5 mm thick plain-weave glass/epoxy composite is generated. Biaxial tests on cruciform specimens are conducted to obtain failure stresses under different loading conditions. The failure investigation validates the capability of the original composite cruciform specimen combined with aluminum tabs for accurately assessing the biaxial failure of composites. Subsequently, the experimental failure envelope is compared with various interactive and non-interactive failure criteria. Notably, the Tsai-Hill and Norris Distortional Energy theories demonstrate substantial agreement with the experimental results.