About numerical analysis of pin loaded joints in laminate structure

Abstract

Nowadays, large aircrafts such as Boeing 787 and Airbus A350 are built in fifty percent of composites (e.g. CFRP, GFRP or Glare). Composites, in general, are brittle and more notch sensitive material than metal alloys. Therefore, mechanical joints of composite parts require a special attention during both the designing and manufacturing process. In the paper, a review of modelling methods for a pin loaded laminate is presented. The simulation of a specimen made of quasi-isotropic CFRP laminate was carried out. Nonlinear analysis was performed using Newton-Raphson method with MSC.Marc. The specimen load capacity was estimated using the maximum stress and Hashin failure criteria in quasi-linear as well as in progressive failure analyses. Failure indices and bearing curves for various contact descriptions (node to segment analytical and discrete, segment to segment and using simplified kinematic ties) and two models of a laminate structure (single layer model and eight orthotropic plies) were compared. The assumed criterion and properties of a failure progressive analysis strongly influence the results. The gradual stiffness reduction analysis with displacement loading in a single layer model results in the upper estimation of the specimen load capacity.