Numerical investigation into failure of laminated composite T-piece specimens under tensile loading

This paper presents a rigorous numerical investigation into the structural response of a composite laminate T-piece specimen subjected to a mechanical “pull-off” load case. Initially, a linear elastic stress analysis is conducted, showing very high stresses at the free-edge. In a further analysis, special-purpose interface elements are then inserted where appropriate and used to predict both the crack pattern and the load to failure. It is demonstrated that that using realistic cohesive maximum strength values requires a very fine mesh. Reducing the values to ensure initiation occurs leads to conservative and mesh independent predictions and that a suitable choice leads to good correlation with the experimental results. This study also shows that the T-piece failure is controlled by crack propagation.