Finite element-incorporated multiscale micromechanics modelling of vehicle crashworthiness for 3-phases hybrid fibres reinforced graphene nano-composite materials

Crashworthiness focuses on the safety and protection of occupants. In addition, not only do energy absorbing members have to absorb sufficient collision energy, but the vehicle structure must be lightweight to improve power consumption. Nevertheless, estimating vehicle crashworthiness is experimentally expensive and time-consuming. Explicit non-linear finite element analysis (FEA) is probably the most commonly used modelling technique to evaluate vehicle behaviour during a crash. However, commercial FE software still lacks efficient explicit modelling of lightweight graphene-based nano-composites. This work develops a simple approach to studying 3-phases hybrid fibres/graphene nanoplatelets-reinforced polymer matrix composites through multiscale modelling. Thermo-elasto-plastic response of composites is considered. The heterogeneous material problem is resolved through a kinematic integral equation. A linear spring model LSM is adopted to account for the interfacial behaviour in a modified Mori-Tanaka scheme The non-linear response is established in the framework of the J(2) plasticity flow rule coupled with the "Lemaitre-Chaboche" ductile damage. The considered material is short glass -fibres/graphene nanoplatelet/Polyamide-Nylon 6 composite. The model is implemented as a UMAT within LS-DYNA((R)) software for automotive crashworthiness applications. The results highlight the crash performance's impact, incorporating the influence of the interfacial behaviour and material damage on the peak crash force and specific energy absorption SEA.