Comparative Analysis of Metal–Thermoplastic Hybrid Circular Structures Under Quasi-static Lateral Loading: Implications for Crashworthiness

Hybridization among different material classes, such as thermoplastics, thermosets, and metals, plays a vital role in advancing the performance of energy-absorbing structures across a wide range of applications. By combining the unique properties of these materials, hybrid structures achieve superior performance characteristics that are unachievable with a single material. Consequently, this work represents a comparative study to investigate the crashworthiness and deformation performance of 3D-printed polylactic acid (PLA) structures integrated within circular aluminum (Al) tubes. To achieve this, different Al/PLA configurations were introduced and then exposed to quasi-static lateral compression tests to evaluate their performance under crash loading. Through this process, the data were systematically collected on the crash load, energy absorption, and displacement responses. Furthermore, the failure histories were documented for each tube, providing valuable visions into the progression and characteristics of structural failures. Following that, a number of critical parameters, including total energy absorbed (U), specific absorbed energy (SEA), and average crash load (FAvg), were used to evaluate crashworthiness. The analysis showed that the ID45-OD85 configuration, i.e., the tube with a 45-mm inner diameter and 85-mm outer diameter, recorded the highest U with a value of 369.16 J, while the ID0-OD50 configuration, i.e., the tube with a 0-mm inner diameter (solid) and 50-mm outer diameter, revealed the best performance in terms of SEA and Favg, respectively, with values of 6.97 J/g and 7.66 kN.