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There is a limit in expense and facilities to perform structural analysis by repeating crash tests using actual vehicles. This paper describes an example of crash analysis by FEM performed by our company, for frontal crash and rollover of a large-sized bus. Regarding the frontal crash analysis, firstly static collapse tests were performed using a scale model of the under-floor structure in order to get the deformation mode, then the structure was analyzed using an FE model. Secondly, an effectiveness of a full model that included the frame model was verified by a frontal crash test at 35km/h. Last, the structural improvement based on the full model was considered. Regarding the rollover analysis, since the event duration is long, a method to utilize partial body model instead of a complete vehicle was proposed in order to reduce calculation time. As practical results, the improved vehicle showed good performance satisfying the target level in frontal crash and rollover tests.

Recently, with increasing demand of safer airbag design and meeting with new US Regulation (FMVSS 208), efficiency of design and experiment on Crash Safety field is strongly needed. This paper explains results of applying CAE method to simulate stress on Front Glass and injuries at out-of-position (OOP) occupant when airbag deploys. Modeling of Front Glass and Airbag, applying of MADYMO dummies, and using Fluid-Structure Code showed relatively good co-relation with CAE and test results. At Front Glass stress simulation, stress distribution mode on the Glass and stress time history on certain points are close with test results. This method will be useful to predict how much stress will be changed on new vehicle that has different layout of Instrument Panel and passenger Airbag. At OOP dummy injury simulation, Head and Chest injuries at AF5 on driver side and 3-year-old passenger side are relatively close in tendency with test results.