20.500.12556/DKUM-98143 A recoverable composite auxetic absorber optimized for low-energy impacts This study proposes, validates, and optimizes an innovative recoverable composite energy absorber based on a foam-filled hexachiral auxetic architecture made of a visco-hyperelastic polymer. The absorber combined a 3D- printed hexachiral frame made of thermoplastic polyurethane reinforced by waste tire rubber (TPU-WTR) and a strain-rate-sensitive highly compressible open-cell polyurethane foam. While the combination of frame auxeticity with foam filling enhanced localized energy absorption, the specific materials adopted guaranteed full recoverability after impact and the variation of geometrical parameters in the hexachiral topology provided a significant design flexibility. A comprehensive mechanical characterization was performed, based on static and dynamic tests, which were used to calibrate accurately their numerical models. An absorber prototype was produced and experimentally tested, assessing the full recoverability at different impact velocities. Finite element models of the absorber were developed by using the identified material models and were validated from the quantitative and qualitative standpoint. Leveraging the design flexibility of the concept, fully parametric models were used to optimize a configuration for an impact of a 12 kg mass at 9 m/s, with a force constraint representative of the limit referred to a collision between a vehicle bumper and a pedestrian leg. The exploited Gaussian process regression (GPR) surrogate models, combined with a genetic algorithm, were able to predict the largely variable performance indices of the different configurations and enabled the identification of an optimal solution that significantly minimized the indentation of the impactor, while satisfying the force constraint and preserving full recoverability. hexachiral auxetic structure recoverable absorbers energy absorption finite element modelling surrogate model optimization technique heksakiralne avksetične strukture obnovljivi absorberji absorpcija energije modeliranje končnih elementov nadomestni model tehnika optimizacije true false true Elsevier Angleški jezik Slovenski jezik https://www.sciencedirect.com/science/article/pii/S2666682026000393?via%3Dihub Članek v reviji 2026-05-20 08:35:10 2026-05-20 08:35:10 2026-05-21 03:07:50 0000-00-00 00:00:00 2026 0 0 15 str. Vol. 20, [article no.] 100733 July 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-04-27 539.2:515.1 276952579 10.1016/j.jcomc.2026.100733 2666-6820 1-s2.0-S2666682026000393-main.pdf 1-s2.0-S2666682026000393-main.pdf 1 7B8F4D2C40068CA2517E6982F9279963 610f007bc7bbed50cffef8768aeef756e84d3ebc7c32aac1cdd8b3b06cd07056 780f7a82-5416-11f1-b984-00155d580e34 https://dk.um.si/Dokument.php?lang=slv&id=206248 https://www.sciencedirect.com/science/article/pii/S2666682026000393?via%3Dihub 0 7dad1fe1-5416-11f1-b984-00155d580e34 https://dk.um.si/Dokument.php?lang=slv&id=206249 Fakulteta za strojništvo 0 0 0