Finite element analysis of collapse of front side rails with new types of crush initiators

Abstract

Today's vehicles are designed with lighter weight to increase performance and to lower fuel consumption, while at the same time meeting the demands of safety requirements. Reducing the cross-section of structural elements to achieve weight reduction can lead to adverse effects on passive safety of the vehicle. In such cases, necessary design modifications must be created to overcome the adverse effects. For this purpose, front rail columns with crush initiators are used in the front zone of cars. These shock-absorbing elements act as energy consuming devices that convert impact energy ( kinetic energy) into plastic deformation energy. Simulation of this energy conversion phenomenon is the subject of this paper. The primary objective of this study is to computationally determine how various crush initiators can reduce the maximum crushing force and how different types of structural modifications affect the observed folding form. The ribs near the crash area are placed in two rows and four different configurations on all facing sides of the column in order to decrease reaction forces and absorb more kinetic energy. These structures are analyzed under axially loaded crushing forces using the explicit nonlinear finite element analysis solver ANSYS/LS-DYNA.