Design and Analysis of Automotive Crash Box Using the Composite Material

¹ PG Student, JSPM’s Rajarshi Shahu College of Engineering, Tathawade Pune, India.
² Faculty Mechanical Engineering Department, JSPM’s Rajarshi Shahu College Of Engineering, Tathawade, Pune, India.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 1 July 2026

Abstract

This study analyze the crashworthiness and design of car crash boxes made of composite and mild steel materials. The behaviour of square, circular, and hexagonal crash boxes under axial impact at a velocity of 4.167 m/s was examined using finite element analysis (FEA). The examination looked at a variety of performance variables, including energy absorption, equivalent stress, and deformation. With simply 7.46 mm of deformation and 3697.3 J of energy absorbed, the square crash box performed better than the other two designs. Lower energy values of 1328.2 J and 1132.4 J were absorbed by the hexagonal and circular models. The crash boxes were reinforced with composite materials including Carbon Fiber and Glass Fiber to assist enhance crash performance. The carbon fiber reinforced square crash box performed the best after reinforcing. Compared to the conventional mild steel square crash box, CFR crash box absorbed up to 4496.7 J of energy, or 21.6% more than the mild steel square crash box. Additionally, the model underwent reduced stress concentration during impact loading and maintained regulated deformation of about 8.67 mm. Stable progressive folding and continuous energy absorption during the loading process were demonstrated by experimental compression testing, which corroborated the computer results. According to the study, composite reinforcement can greatly increase crashworthiness and aid in the design of lightweight vehicles. The CFRP-reinforced square crash box was determined to be the best option for upcoming automotive safety applications out of all the tested configurations.