FINITE ELEMENT MICROMECHANICAL ANALYSIS AND EXPERIMENTAL CONFIRMATION OF THE ELASTIC PROPERTIES OF STITCHED COMPOSITE MATERIALS

摘要

The reinforcement of polymer matrix composites by through-the-thickness stitching is a promising technique for raising the damage tolerance of laminar structures. In this paper, a three-dimensional finite element micromechanical modeling approach is proposed for predicting the macro-elasticity constants of stitched/RTM CFRP composites. In the model, the actual shape of stitching yarn and the position between yarns and laminate were taken into account. The unit cell of the model is picked up from entire thickness of stitched laminate. Each lamina was taken as a body not a panel and the elastic constants were calculated in three directions. As fewer hypotheses taken, the analysis result is more precise. Comparing the relevant predictions with the experimental results validates the model presented in this paper. The comparison shows that there is good agreement for the elastic properties and it can be used in the engineering design.