Abstract The elevated strain rate compressive response of closed-cell polyvinyl chloride (PVC) foam at various densities is investigated. Two loading directions, (i.e., parallel and perpendicular to foam rise direction) were considered to investigate structural anisotropy. The elevated strain rates tests (up to 200 s−1) were performed using a customized drop tower device. Engineering stress/strain behavior, energy dissipation, and maximum stress capacity were obtained for each density and compared against each other. Except for the lowest density of 45 kg/m3, strain rate effects were clearly observed through increased compressive strength and plateau stress when loading in the foam rise direction. The strain rate effect is more evident at higher densities. However, no significant strain rate effect was observed when loading perpendicular to the foam rise direction. Scanning electron microscopy (SEM) analysis showed that plastic hinges are the primary deformation mechanism for PVC foam cells. An analytical model has been calibrated using the experimental results and successfully predicted the mechanical response of the foam. Shape anisotropy has been measured employing the SEM images. The analytical approach was also able to predict the foam's anisotropic mechanical response.

中文翻译：

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硬质 PVC 泡沫在应变率高达 200 s-1 时的各向异性压缩行为

摘要 研究了不同密度下闭孔聚氯乙烯 (PVC) 泡沫的高应变率压缩响应。考虑两个加载方向（即平行和垂直于泡沫上升方向）来研究结构各向异性。使用定制的落塔装置进行高应变率测试（高达 200 s-1）。获得每个密度的工程应力/应变行为、能量耗散和最大应力容量并相互比较。除了 45 kg/m3 的最低密度外，在泡沫上升方向加载时，通过增加的压缩强度和平台应力可以清楚地观察到应变率效应。应变率效应在较高密度下更为明显。然而，当加载垂直于泡沫上升方向时，没有观察到显着的应变率效应。扫描电子显微镜 (SEM) 分析表明，塑性铰链是 PVC 泡沫细胞的主要变形机制。已使用实验结果校准分析模型并成功预测泡沫的机械响应。已使用 SEM 图像测量了形状各向异性。分析方法还能够预测泡沫的各向异性机械响应。已使用 SEM 图像测量了形状各向异性。分析方法还能够预测泡沫的各向异性机械响应。已使用 SEM 图像测量了形状各向异性。分析方法还能够预测泡沫的各向异性机械响应。