Finite element modelling of vehicles and human body models for passive safety

The aim of this thesis work is to model and validate a Finite Element (FE) model which reproduces a frontal full-width impact test according to EuroNCAP regulation, using LS-DYNA non-linear explicit finite element code. Furthermore, this study is focused on the simulation of the driver conditions over the whole test, from the initial impact to the rebound of the vehicle. In order to evaluate driver injuries during the test, a sled model is used in this work to simulate the cockpit of a vehicle during the impact. This model is a simplified FE environment which reduces computational time of the simulation and allows to change set-up of the vehicle in easiest way. The sled represent a very detailed cockpit and it is obtained starting from a freeware model of a 2012 Toyota Camry passenger sedan, deleting and cutting some components in order to have a compact structure. The motion of the structure is based on a reverse-firing sled and it is applied to the model defining four different velocity curves on four rigid parts, modeled on the sled frame. As in a real vehicle test configuration, the sled system is equipped with passive safety devices for the occupant, in particular, a simple driver airbag and a driver seat belt are modeled and included into the simulation. The validation of the model is performed comparing the sled simulation to the full-scale crash test, computing physical parameters in driver area in two configurations: with Human Body Model and without HBM. To prepare the simulations with the HBM, some steps are performed before including all models in the FE environment. First of all, the positioning of the occupant body is taken place using the PIPER program, obtaining a HBM set in a standard position as a real dummy. Then, a driver sitting is simulated in order to create the footprint on the seat cushions, avoiding interpenetrated elements when models are loaded in simulation environment. At last, the seat belt routing is performed to secure the HBM to the seat.