Crushing behavior and deformation mechanism of additively manufactured Voronoi-based random open-cell polymer foams

Abstract

Listen

Translate article

The macroscopic mechanical performances and the mesostructural deformation mechanisms of random open-cell polymer foams subjected to quasi-static loading were investigated. Three typical materials, namely, polyamide 6 (PA6), polyamide 12 (PA12), and polylactide (PLA), used in the additive manufacturing techniques, were considered as the base materials of open-cell polymer foams. Polymer foam specimens with predesigned mesostructural configurations and different relative densities were examined under quasi-static compression. The experimental results showed that the deformation modes and mechanical responses of the polymer foams exhibited a strong dependence on the properties of bulk materials and the fabrication process. It was found that elastic buckling dominated the failure of the PA12 and PA6 foams, whereas the failure of the PLA foams was dominated by strut collapse and the debonding of the relatively weak interlayers. The PA6 and PA12 foams, with low relative densities, could significantly recover from their compacted states, whereas the PLA foams were crushed without distinct rebounding. The elastic modulus, plateau stress, and specific energy absorption of the fabricated foams were quantified by using scaling laws as a function of the relative density. A revised statistical constitutive model was proposed for the random open-cell polymer foams under compression and it was confirmed that the revised model could accurately capture the whole crushing behavior of the foams.