Enhancing energy absorption in printed PLA components through post-processing and topological optimization

Mechanical energy absorbers convert kinetic energy into deformation energy during impact events. This study investigates 3D-printed polylactic acid components as mechanical absorbers, focusing on their performance enhancement through thermal post-processing and topology optimization. A key challenge in additive manufacturing is the presence of thermal gradients, which affect interlayer bonding and reduce mechanical strength. Thermal annealing was applied to printed components to address this, significantly improving their crushing resistance. Experimental results showed a 40.6% increase in energy absorption for a simple crash box and a 12.5% improvement for a honeycomb structure. Finite element simulations were used to model the crushing process and guide geometry optimization. The combination of post-processing and optimized lattice structures led to a 32-fold increase in peak crushing force, with only a fivefold increase in component weight. These findings demonstrate that with proper design and treatment, printed polylactic acid components can serve as effective, customizable energy absorbers in various engineering applications. • Printed PLA components can be used to develop mechanical energy absorbers. • Thermal annealing increases the peak crushing force of printed PLA by up to 43.3%. • Optimized honeycomb geometry enhances mechanical energy absorption in PLA crash boxes. • Post-printing heat treatment improves interlayer adhesion, reducing anisotropy in PLA.