Filler strengthening of foam-filled energy absorption devices using CFRP beams

The crashworthiness of fiber reinforced plastics (FRP) is attracting more interest as they are currently contributing to several industries. In the present study, internally strengthened foam-filled rectangular carbon fiber reinforced plastics (CFRP) composites are presented for energy absorption applications. Commercially available carbon/epoxy beams/tubes were employed. After arranging the internal strengthening, each structure was filled with foam for better structural integrity. The structures were subjected to lateral compression and their crashworthiness was assessed using the peak load, the mean crushing load, the stability during post-crushing, the energy absorption, and the specific energy absorption. Up to 100% improvement was observed in both the energy absorbed and the load carrying capacity (refereeing to the peak load and the mean crushing load). Moreover, the stability in the post-crushing stage did not show significant dependency on the strengthening arrangement. Since it is highly dependent on the specimen weight, which is different from one specimen to another, the specific energy absorption showed different responses compared to the scalar value of the energy. For some configurations, internal strengthening had a negative effect on the specific energy. In contrast, an improvement of up to 22.5% was achieved for the other specimen configurations.