Composite forming simulation of a three-dimensional representative model with random fiber distribution

Abstract

Although fiber reinforced plastic is a statistically homogeneous material, its microstructure with randomly distributed reinforcements has a significant impact on the actual residual stresses induced by the forming process. By leveraging massively parallel computing, forming process of a three-dimensional representative thermoplastic composite model with randomly distributed long fibers was simulated using the finite element method. The residual stresses within a monitoring window on the symmetry plane of the model were extracted and analyzed to manifest the actual phenomena according to the shear lag effect and edge effect. Simulation results were analyzed considering stress distribution, probability, and influence of the inter-fiber spacing, temperature gradient, and resin viscoelasticity. The proposed three-dimensional micro model is beneficial for obtaining more reliable and comprehensive results in comparison with models that do not consider stress along the fiber direction, and therefore, is advantageous to research on composite forming.