Lateral crashworthiness of UV‐pultruded hat profiles with 3D printed bio‐inspired inserts

Abstract This paper investigates the potential of UV pultrusion to produce hat‐shaped profiles reinforced with quasi‐isotropic non‐crimp fabric to withstand lateral loading scenarios that are gaining relevance in automotive applications. Out‐of‐plane crushing tests proved that the new profile capacities were comparable to those from similar composite structures manufactured with less productive prepreg‐based technologies. Additionally, when filling the profiles with a 3D‐printed insert inspired by the trabecular structure of beetle forewings, the synergetic effect achieved avoided the critical failure modes of each component; the yield‐arc post‐failure mode of the hollow profile and the catastrophic blasting of the 3D‐printed insert. This way, the load‐bearing and energy dissipation capacities were improved by 570% and 340%, respectively, with the 82% heavier filled specimens. Three‐point bending tests demonstrated that the quasi‐isotropic reinforcement configuration effectively constrained damage extension, preventing propagation along the hat profiles. The integration of a trabecular insert resulted in a more progressive failure mode, increasing the maximum load by 55% and doubling energy absorption with only a 9% weight penalty. These results support the competitiveness of UV‐pultruded profiles for lateral crashworthiness applications and present the integration of trabecular inserts as a promising strategy to further improve their performance. Highlights Hollow and filled profiles were assessed under lateral crush and bending. Profiles with quasi‐isotropic reinforcement were manufactured by UV pultrusion. Lateral crashworthiness of UV pultruded profiles was comparable to prepreg parts. Bio‐inspired 3D printed inserts enhanced the lateral performance of hat profiles.