Mixed-mode damage into a CGRP cruciform subjected to biaxial loading

In this paper, a three-dimensional progressive damage model (PDM) is implemented within a chopped glass-reinforced polyester (CGRP) cruciform structure for modelling its damage under loading. Three different cruciform specimens subjected to biaxial tensile loading are studied. In order to simulate the computational behaviour of the composite, the constitutive model considers an initial elastic behaviour followed by strain-softening. The initiation criterion defined is based on the maximum principal stress of the composite and once this criterion is satisfied, stiffness degradation starts. For the computation of damage, the influence of the fibre and the matrix are taken into account within the damage rule. Realistic values of the energy dissipated during damage are computed. The computational results obtained by means of an explicit time marching solver are compared with experimental outcomes for validation purposes. Finally, it is concluded that the PDM is able to localise the damage effectively as well as predicting its initiation. In the best of authors' knowledge, this is the first time a three-dimensional PDM is implemented into a composite cruciform structure subjected to biaxial loading.