Analysis and Experimentation of a Crash Box

Abstract

A separate component in vehicle which is mounted in between main frame and front bumper of the car is called Crash box. The Crush Box is a thin-walled deformable structure attached between the vehicle bumper and the chassis. The Crush box is quite more important for absorbing the impact energy. In case of front car crash collisions, crash box is expected to deform and absorb crash energy that can be transferred to other cabin parts so that damage to the occupant cabin and occupant is minimized. The design of such structures for progressive crush is very important because if these structures deform at very high crushing forces there is high risk to bio-mechanical damage to the vehicle occupants. Hence it is important that the design of such structures should be to maximize the energy absorption while maintaining the peak force below an allowable threshold. Here, progressive crush is a mode of axial crush that initiates near the tip of the crash box and then progresses towards rear. Crash box structure provides safety and comfort to the passenger at the time of front impact. It works as safe guard for the costly components behind the bumper like engine hood and cooling system. In this project plane crash box geometry with varying thickness is studied for the energy absorption. Study is based on analytical, experimental and numerical work. Various parameters like width, thickness, taper which affects on the crash box performance are studied. Crash box crushing behavior is analyzed by using quasi static method. Experimental test is performed on UTM machine. Quasi-static simulation is performed using ABAQUS. Good agreement obtained in the results of analytical, experimental and numerical method. By varying the parameters and application of beads different designs are proposed and simulated for the maximum energy absorption. Application of various positioned beads show good influence on the energy absorption.