Numerical and experimental investigation into failure of T700/bismaleimide composite T-joints under tensile loading

A finite element model for a composite T-joint structure under tensile loading has been established to simulate and analyze failure mechanisms, carrying capacities, in-plane and interlaminar damage behaviors based on the Tsai-Wu failure criterion and a cohesive zone model. Strains on the stress-concentration zone of the T-joint structure during loading were measured to validate the FEM model. The results showed that the simulated results had a good agreement with that of the measurements. The carrying capacity of the composite T-joint is mainly determined by failure modes, which can be changed by reducing fillet-filling ratio in the fillet of the T-joint and initiation and propagation paths of delamination cracks between the fillet and the L-ribs. The maximum tensile load of the T-joint calculated by FEM methods was 1854N, while the experimental value was 1862N.