Short Fiber Reinforced Plastics in Explicit Simulations: State of the Art Approaches for Efficient Modeling

Key to the fulfillment of tomorrow’s visions in terms of CO 2 reduction and electrical mobility is the ability to effectively design lightweight structures. In this context already today short fiber reinforced plastics is entering realms of application where exclusively metals have been used in the past. Especially in the automotive industry all kind of different performances have to be tested on new and challenging parts which exhibit highly complex material properties. Covering performances means to cover everything from static load cases over dynamic behavior including crash and failure up to the full life time prediction. The simulation of plastic composites proves difficult due to the fibers in the reinforced matrix which cause anisotropic and locally different material behavior. This can be observed to be especially true for stiffness and failure. Even more, the local material behavior depends strongly from the processing step, in this case from the injection molding conditions. All this adds new complexity to the development process based on computer simulations. For an accurate prediction the anisotropy caused by the fiber reinforcement, the material nonlinearities of the matrix as well as strain rate dependencies have to be taken into account. Modeling of failure has to be added, which proves especially challenging for these complex materials. Via such material models it is possible to set up a simulation chain which integrates results from injection molding simulations in the computation of the dynamic response of the part. This presentation will focus on recent advances in the DIGIMATTM technology for modeling short fiber reinforced plastics in explicit simulations. A new approach for the simulation of crash and failure will be presented which helps saving CPU time and provides accurate prediction of the failure.