MODELING OF DISCONTINUOUS LONG FIBER COMPOSITES: PREDICTION OF STIFFNESS, STRENGTH AND MANUFACTURING DEFECTS USING RVES

摘要

Discontinuous Fiber Composites (DFC) are increasingly being used for structural components in aerospace or automotive industries. However, because the microstructure differs from the continuous fiber composites, new dedicated modeling methods have to be defined in order to support their design. Such methods must be able to take into account accurately the local orientation of each chips which is not obviously predefined. The presentation will focus on two aspects. The first one will expose how Representative Volume Elements (RVE) of DFC accounting local orientation can be defined and solved by the FEM in order to predict their stiffness and strength. Such results can then be used to design a whole component. The second aspect will show how such RVEs can be used to predict the residual thermal stresses that can appear during the whole curing cycle. The knowledge of such stresses allows to predict the apparition of possible micro-cracks between the chips during the cooling stage. These aspects will be illustrated using examples of simulation based on the Digimat platform.