The purpose of this study is to evaluate and compare two front body structure designs of a new car program using three-dimensional (3D) lumped spring-mass model so called `MADYMO 3D frame model' in the view of frontal crash with concept drawing only. A MADYMO 3D frame model, composed of a number of bodies and joints, was built for a current vehicle model and correlated with full car crash analysis results from explicit finite element (FE) analysis for FMVSS (Federal Motor Vehicle Safety Standard) 208 and AMS (Auto Motor und Sports) crash conditions. Then the same method was applied to a new car structure. The new 3D frame models of two front structure design concepts were built, and the result was compared for two crash conditions. Two models were required to reduce footwell intrusion to meet the design target. Several design modifications were tried to reduce footwell intrusion for both models. The footwell intrusion was reduced quite much by introducing connecting concept and reducing front rail bending stiffness for two models, respectively. (A)
Abstract