Failure prediction of composite T-beams subjected to lateral load on the web

A study of the design and mechanical behaviour of co-cured T-beams subjected to lateral loading on the web is presented. The T-beams were manufactured by press moulding from pre-pregs of uni-directional and fabric glass reinforced high performance epoxy matrix. A special fixture was designed in order to carry out tests where the T-beams were laterally loaded on the web and clamped on the flange. Analytical and numerical studies were performed to predict the failure load to compare with the experimental results. The multilayer anisotropic continuum theory for delamination analysis of curved beams subjected to end moments and forces was used to compute the delamination stresses in the quarter cylindrical beam of the junction between the flange and the web. Finite element analyses of the T-beams were performed using plate/shell elements and two models were used for the joining between web and flange, to compute the planar stresses in the beam. The scatter obtained in the experimental results can be explained by the presence of two failure modes: one due to delamination associated with the through the thickness stresses developed in the curved part of the beam, the other related with failure occurring due to tangential stresses in the most highly stressed plies.