Microstructure-based modeling of the creep behavior of long-fiber-reinforced thermoplastics

Aim of this work is the prediction of the creep behavior of long-glass-fiber-reinforced polypropylene by microstructural simulations. This paper describes the generation of representative volume elements (RVE) for finite element simulations (FEM) employing a novel approach which takes into account the consolidation process of the composite during fabrication. First, a stack of straight fibers is generated according to the experimentally measured orientation distribution, then the compression of the fiber stack is numerically simulated and finally the remaining pores are filled with matrix elements to form the RVE. The resulting orientation distribution of the RVE is compared with measurements from computer tomography and shows excellent agreement. The capabilities of the FEM model are demonstrated by comparison of the elastic properties of the composite to experimental measurements.