Hybridization effect on energy absorption capacity of composite crash boxes

Abstract Crash boxes are safety elements generally made of metallic materials and mounted on the chassis of vehicles to prevent possible injuries to driver and passengers by absorbing the energy generated during a collision and ensuring integrity of vehicle. In order to save fuel and reduce harmful gases released into the environment, the proportion of metallic materials used in vehicles is decreasing and being replaced by composite materials. While composite materials are as durable as metallic materials, they are preferred because they are lighter. In this study, circular composites consisting of glass (S1), aramid (S2), carbon (S3), and hybrid combinations of aramid‐carbon‐glass (S4), carbon‐glass‐aramid (S5), and glass‐aramid‐carbon (S6), all with epoxy resin matrices, were produced using the vacuum infusion method and investigated. Crush parameters, maximum peak loads and specific energy absorption of hybrid tubes with different fiber types and winding order were compared. S3 tube had the best energy absorption performance among all samples of 257.288 Joules, while the worst energy absorption performance was obtained for S2 tube with 30.944 Joules. Among the hybrid samples, the best result was determined as 166.50 Joule with hybrid S5. Although the energy absorption capacities of hybrid composite tubes were close to each other, they had lower results for energy absorption and specific energy absorption than S1 and S3. For specific energy absorption, as with energy absorption, the best result was obtained with S3, while the lowest result was obtained with S2. Highlights The aim of this study is to evaluate the performance of composite crash boxes. The effect of fiber type and hybridization was examined. Specific energy absorptions and maximum contact forces were compared. Cylindrical samples were produced by vacuum infusion. The variation of damage depending on fiber type was investigated.