Design optimization studies applied on a hybrid side sill structure of a new hydrogen plugin fuel cell vehicle concept

Kurzfassung

Growing environmental awareness, strict regulations on CO2 emissions and passenger safety inspired the manufacturers to produce safe and light weight vehicles. The Institute of Vehicle Concepts at DLR is currently working on development of next generation cars to meet the requirements of future mobility. The Inter Urban Vehicle for long distance powered by hydrogen fuel cells is one of the concepts of the DLR’s Next Generation Cars project. Large percentage of the structure of this model is made of lightweight materials like carbon fiber composites. As this model is designed with a sliding door concept, side pole crash is the critical load case for this vehicle. Therefore, the side sill structure in this vehicle concept plays an important role in absorbing 50% of the kinetic energy in the event of crash. The main aim of this master thesis work is to develop an optimized side sill structure with light weight design. Initially, the parameters influencing the crashworthiness performance and Specific energy absorption (SEA) of side sill structure are identified. The identified parameters are then optimized using sub-component level tests like three-point bending impact test to determine the ratio of CFRP and Aluminum required to build a crashworthy and a lightweight structure. Based on the results of optimization, the parameters like thickness and the response values like mass of the structure and Specific energy absorption (SEA) are optimized for nearly realistic floor model. Finally, the obtained optimized parameter results are validated through implementation in crash simulation of actual floor model.