No abstract

A methodology was developed to design the front end structure of a car with a short front-end to meet Frontal Impact safety requirements. The methodology is based on CAE tools, and it is to be applied in the early stages of the design process. It includes setting the vehicle target pulse, obtaining the component targets, designing the structural components and sub-systems, and evaluating the vehicle system by Finite Element analysis. The process is based in two CAE tools, an FCRASH Finite Element Hybrid model for the structural analysis, and a MADYMO model for the occupant simulation. The Hybrid model was chosen for the structural analysis in order to allow the upgrade of the CAE model during the different stages of the design process. Modifications of the process are discussed in order to meet different crash requirements.

Until recently, frontal crash analysis and tests were performed to predict the performance and behavior of cars to meet full frontal crash safety requirements. Little has been done so far to control the energy absorption during an offset frontal crash. This topic has become a very interesting and challenging issue since it will be included in the federal regulations in the coming years. In offset crash, the load is applied to one side of the front end, leaving the other side partially unloaded. In light of this situation, cross-members have to be carefully designed in order to absorb and safely transmit part of the offset crash load to the opposite side. This paper will describe the theoretical performance of the front structure under an offset crash and at the same time identify all related parameters that influence this behavior. A computerized analysis of the single, full and offset crash will be performed and results and comparisons will be tabulated and graphed.