Lightweight design: detailed comparison of roof panel solutions at crash and stiffness analyses

According to auto industry’s interest for reducing fuel consumption, composite materials have gained lots of attention due to their superior characteristics. The available finite element model of the Toyota Yaris has been modified through the substitution of the steel roof with composite and aluminium solution, to evaluate the change in the static and dynamic stiffness of vehicle body and the change in the structural response of the vehicle in case of full frontal crash. ‘Piecewise Linear Plasticity’ and ‘Enhanced Composite Damage’ material models available with LS-DYNA are applied to model metal and composite roof panels, respectively. Analyses have been done based on the same and modified roof panel thickness. Results reveal that the composite solutions give comparable value of the body stiffness, although with lower energy absorption capacity of the roof in comparison with the steel solutions but they have large contribution, around 40%, to the weight reduction of vehicle roof panel along with the acceptable structural performance.