True stress-strain curves used in finite element vehicle model

The finite element method utilizes a piecewise solution to simulate the impact event. True stress and true strain at different strain rates must be used in order to adequately describe the material parameters. In this paper, a method is presented to obtain steel plate’s true stress-strain curves. And those curves are used in an off-road vehicle’s 40% offset-barrier impact. Correlation of the finite element analysis results with actual test data is discussed. Base on this correlation, several improvements are put forward on the structure of the off-road vehicle’s frame. The results of crash simulation show that most of impact energy is absorbed by the front of frame and the crew cabin’s deformation is very little after vehicle’s improvement.