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 sub jected to lateral loading on the web is presented. The T-beams were ma nufactured by press moulding from pre-pregs of uni-directional and fab ric glass reinforced high performance epoxy matrix. A special fixture was designed in order to carry out tests where the T-beams were latera lly loaded on the web and clamped on the flange. Analytical and numeri cal 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 an d forces was used to compute the delamination stresses in the quarter cylindrical beam of the junction between the flange and the web. Finit e element analyses of the T-beams were performed using plate/shell ele ments and two models were used for the joining between web and flange, to compute the planar stresses in the beam. The scatter obtained in t he experimental results can be explained by the presence of two failur e modes: one due to delamination associated with the through the thick ness stresses developed in the curved part of the beam, the other rela ted with failure occurring due to tangential stresses in the most high ly stressed plies.