Quasi‐static axial crushing of multi‐tubular foam‐filled carbon fiber reinforced composite structures

Abstract In automotive design, a key aspect in limiting injuries in the event of collision is the ability of vehicle's structures to absorb high quantities of energy. Recently, automobiles have been designed with materials such as carbon fiber‐reinforced polymers to replace the conventional metallic materials, to boost structural safety and fuel efficiency. In this study, various combinations of carbon fiber‐reinforced plastic and Kevlar‐reinforced polymer composite tubes were assembled to form multi‐tubular composites and their crushing properties were investigated under quasi‐static axial compression. A total of five different combinations were designed and tested. The results showed that the addition of intermediate tubing system in the hollow composite tubes significantly improved the load‐bearing and energy absorption capabilities of the composite tubes. In addition, these configurations were also filled with polyurethane (PU) foam. It was shown that, apart from specific energy absorption (SEA), all the other parameters, such as peak load, mean load, crushing force efficiency, and overall energy absorption ability, were enhanced with the addition of foam. The SEA parameter showed inconsistent behavior, and this was attributed to the weight addition caused by the addition of foam in the composite tubes. Highlights This study examined the crashworthiness properties of multi‐tubular structures. Placing of intermediate tubing showed great improvement in absorption capacity. The system with carbon‐based intermediate tubes performed the best. Filling PU foam within the structures also improved the load‐bearing properties. The SEA was seen to reduce with the addition of PU foam.