Efficient Characterization and Modelling of the Nonlinear Behaviour of LFT for Crash Simulations
Modeling the nonlinear material behaviour of long fiber reinforced thermoplastics(LFT) presents a challenging task since local inhomogeneities and nonlinear effects must betaken into account also on the microscale. We present a computational method with which we can predict the nonlinear material response of a composite material using only standard DMA measurements on the pure polymer matrix material. The material models considered include plasticity, damage, viscoelasticity, and visco-plasticity as described in . These models can be combined similar to the model from  and extended to the composite by assigning linear elastic properties to the fibers. The mechanical response of the composite is computed using an FFT-based technique .The geometry of the composite, in particular t he fiber orientation, can be characterized using injection molding simulations or micro CT scans. We create virtual models of the composite using the algorithm of . We show that with this method, the material behaviour of the composite can be predicted while the experimental complexity needed for the material characterization is low.