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.

研究了准静态载荷下无规开孔聚合物泡沫的宏观力学性能和细观结构变形机理。在增材制造技术中使用的三种典型材料，即聚酰胺6（PA6），聚酰胺12（PA12）和聚丙交酯（PLA），被认为是开孔聚合物泡沫的基础材料。在准静态压缩下检查了具有预先设计的细观结构构造和不同相对密度的聚合物泡沫样品。实验结果表明，聚合物泡沫的变形模式和力学响应表现出对散装材料性能和制造工艺的强烈依赖。发现弹性屈曲主导了PA12和PA6泡沫的失效，而PLA泡沫塑料的破坏主要是支杆塌陷和相对较弱的中间层脱粘。相对密度低的PA6和PA12泡沫可以从压实状态显着恢复，而PLA泡沫被压碎而没有明显的回弹。通过使用比例定律作为相对密度的函数来量化所制造泡沫的弹性模量，平台应力和比能吸收。针对压缩条件下的无规开孔聚合物泡沫，提出了一种修正的统计本构模型，证实了该修正模型可以准确地捕捉到泡沫的整个破碎行为。可以从压实状态显着恢复，而PLA泡沫被压碎而没有明显的回弹。通过使用比例定律作为相对密度的函数来量化所制造泡沫的弹性模量，平台应力和比能量吸收。针对压缩条件下的无规开孔聚合物泡沫，提出了一种修正的统计本构模型，证实了该修正模型可以准确地捕捉到泡沫的整个破碎行为。可以从压实状态显着恢复，而PLA泡沫被压碎而没有明显的回弹。通过使用比例定律作为相对密度的函数来量化所制造泡沫的弹性模量，平台应力和比能吸收。针对压缩条件下的无规开孔聚合物泡沫，提出了一种修正的统计本构模型，证实了该修正模型可以准确地捕捉到泡沫的整个破碎行为。