Crashworthiness of Additively Manufactured Crash Boxes: A Comparative Analysis of Fused Deposition Modeling (FDM) Materials and Structural Configurations
Ahmed Saber, A. M. Amer, Ali I. Shehata, Hassan Elgamal, A. Abd_Elsalam
Abstract
Crash boxes play a crucial role in automotive safety by absorbing impact energy during collisions. The advancement of additive manufacturing (AM), particularly Fused Deposition Modeling (FDM), has enabled the fabrication of geometrically complex and lightweight crash boxes. This study presents a comparative evaluation of the crashworthiness performance of five FDM materials, namely, PLA+, PLA-ST, PLA-LW, PLA-CF, and PETG, across four structural configurations: Single-Cell Circle (SCC), Multi-Cell Circle (MCC), Single-Cell Square (SCS), and Multi-Cell Square (MCS). Quasi-static axial compression tests are conducted to assess the specific energy absorption (SEA) and crush force efficiency (CFE) of each material–geometry combination. Among the materials, PLA-CF demonstrates superior performance, with the MCC configuration achieving an SEA of 22.378 ± 0.570 J/g and a CFE of 0.732 ± 0.016. Multi-cell configurations consistently outperformed single-cell designs across all materials. To statistically quantify the influence of material and geometry on crash performance, a two-factor ANOVA was performed, highlighting geometry as the most significant factor across all evaluated metrics. Additionally, a comparative test with aluminum 6063-T5 demonstrates that PLA-CF offers comparable crashworthiness, with advantages in mass reduction, reduced PCF, and enhanced design flexibility inherent in AM. These findings provide valuable guidance for material selection and structural optimization in FDM-based crash boxes.