泡沫填充蜂窝材料动态力学性能的物质点法模拟

Dynamic behavior simulation of foam filled honeycomb using material point method

  • 摘要: 为了研究泡沫填充蜂窝材料(FFH)在动态加载下的力学响应和吸能效果,采用物质点法建立了FFH的细观物质点模型。泡沫细观物质点模型的应力-应变曲线与理论模型和实验结果吻合较好,FFH细观物质点模型的变形失效模式与实验结果一致。研究发现,填充泡沫和蜂窝分别通过塑性变形和屈曲变形吸能,填充泡沫对蜂窝吸能效果增强效应显著。获得了填充泡沫密度和加载应变率对FFH变形损伤和吸能效果的影响。填充泡沫密度增加,FFH动态力学性能提高,吸能总量增加,蜂窝吸能增加。填充泡沫增强了蜂窝的屈曲强度,促进蜂窝抵抗更多的变形。FFH的应力-应变曲线对加载应变率敏感,其吸能效果受加载应变率一定程度的影响,但总量变化不超过15%。吸能总量和组分吸能比例由FFH整体结构决定,与加载应变率无关。

     

    Abstract: To investigate the dynamic behavior and energy absorption performance of foam filled honeycomb (FFH) under impact loading, a series of meso-structure models were established by material point method (MPM). The stress-strain curves of foam meso-structure models agree well with the theoretical model and experimental data. The deformation and damage morphologies of FFH models are consistent with those of experiments. The result shows that the filled foam and honeycomb consume energy through plastic deformation and buckling separately, and the filled-foam makes a remarkable enhancement effect on the energy absorption of the honeycomb. The influences of the filled-foam density and loading strain rate were investigated. As the filled-foam density increases, the dynamic behavior of FFH turns better, the total energy absorption and that of honeycomb component increase as well. Since the filled-foam intensifies the buckling strength of the honeycomb, the honeycomb could withstand more deformation. The stress-strain curves of FFH are sensitive to the loading strain rate, which has a certain impact on the energy absorption performance, and the total energy absorptions are confined to less than 15%. The total energy absorption and those of each component are determined by the FFH structure, and not irrelevant with the loading strain rate.

     

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