NUMERICAL AND EXPERIMENTAL-ANALYSIS OF THE COMPACT TENSION TEST FOR AGROUP OF MODIFIED EPOXY-RESINS

A three-dimensional finite element analysis based on a general materia l model implemented in the DYNA3D code was carried out in order to sim ulate crack initiation and propagation in a typical neat resin fractur e toughness test specimen (CT-specimen). Additionally, the effect of c rack initiation and the dynamics of crack propagation was investigated . The simulation of the fracture process in an isotropic neat resin is the baseline for the next step: the simulation of the crack propagati on in a continuous fibre reinforced composite. The crack initiation an d crack propagation were measured in the compact tension test for five different epoxy resin formulations. The calculated stress distributio n was verified by comparing the calculated stress distribution with a photoelastically measured distribution. In the case of a continuous cr ack propagation, simulation and experiment were in good agreement; in the case of a stick-slip crack propagation, the model would have to be extended to include crack tip blunting effects.