Numerical Investigation and Optimization of axially impacted metallic and FRP tabular crash elements
In the automotive and aerospace industries, the axial crushing behavior of metal and FRP tubes has become the foundation for a crashworthy structure. Dynamic Crash tests were performed on metal and FRP tubes to study their axial crushing behavior when subjected to impact loads. Different crash mechanisms were used to study their behavior. The main focus of this thesis was to study the energy absorption characteristics and the SEA values of the metal and FRP tubes. Numerical FE models were developed using LS-Dyna to simulate the crushing response of Aluminum, CFRP and GFRP tubes. Single layer approach was used to model the composite laminate. This consisted of developing the most efficient way of modeling the laminate along with proper element formulations and contact definitions. The material models used in this study were MAT54 and MAT58. Initially, the material parameters used for these materials was taken from the available literature and then these material parameters were optimized using LS-Opt to get results which were then compared with the experimental results. The developed FE model and the optimized material parameters predicted the crushing response of the tubular specimens very well with the experimental results. The results obtained helped in understanding the energy absorption and the crush response of metal and FRP tubes. All this data was obtained from the generated force displacement curves. The parameters of focus to study the crash response were the peak force, mean Crushing force, energy absorbed and the SEA values.
Duisburg-Essen, Univ., Master Thesis, 2018