This paper was produced for the 2019 NAFEMS World Congress in Quebec Canada

Resource Abstract

In aeronautics, the percentage of continuous long fiber reinforced composite parts in the latest aircraft generations, such as the Airbus A350, exceed 50%. The introduction of the material in the automotive industry is however hindered by the high cost of the raw material and the large cycle times during the manufacturing. While these observations are mainly true for thermoset based continuous fiber composites, discontinuous short and long fiber composites, especially with thermoplastic resin, have been found to overcome these limitations.



While continuous fiber composites are mainly used in primary structures that undergo heavy loading conditions, discontinuous composites are commonly applied to secondary structures with moderate loadings. The involved manufacturing processes are suitable for large series production and allow for the design of function integrated parts. Fiber reinforced thermoplastics (Short and Long Fiber Reinforced Polymers GMT, SMC) are widely used in the automotive industry in mass production.



For the introduction of discontinuous fiber reinforced composite materials in an early design phase, a virtual assessment of the material properties is vital in order to be able to carry predictive simulations. This includes both the simulation of the manufacturing process and the structural simulation. Since the latter is strongly dependent on the material processing, both analysis types should be combined in an integrated process : prediction of the statics and crash performance of fiber reinforced thermoplastics parts can be achieved only by accounting for the full manufacturing history.



The present contribution will present how micromechanics can be used efficiently to assess the performance of short fiber reinforced thermoplastics and Sheet Molding Compound (SMC) and how simulation can be enhanced to handle multiscale phenomena within industrial constraints such as CPU time. To this end, local information about the material structure, predicted by a manufacturing process simulation, has been transferred and mapped automatically on the performance composite part model.



In the subsequent analysis, the impact of the manufacturing process and the resulting local variation of material properties has been shown on component cases.