Enhancing Energy Absorption in PLA Prints Through Post-Thermal Treatment

Energy absorption is a pivotal factor in impact mitigation, especially in engineering applications that demand lightweight and efficient mechanical absorbers. Traditionally, crash boxes are manufactured using metallic materials; however, advancements in additive manufacturing present new opportunities for producing lightweight prototypes quickly, without the need for specialized tooling. This study explores the potential of 3D-printed polylactic acid (PLA) components with tailored stiffness to optimize energy absorption performance. By combining material properties, manufacturing parameters, and design strategies, varying mechanical strengths were achieved. Furthermore, the performance of the best combination was enhanced through post-processing via thermal treatment, resulting in improved crushing metrics. Experimental results revealed a 33% increase in energy absorption for honeycomb structures with variable thickness designs, demonstrating the benefits of tailored stiffness distribution. These findings highlight the promise of variable-thickness 3D-printed composites as highly effective and customizable energy absorbers, offering innovative solutions for micromobility and other engineering applications.