提出了一个用于表征泡沫非线性卸载与残余变形力学行为的简单方法。结合超弹本构模型与弹塑性本构模型，把塑料泡沫看成由相同横截面积但不同厚度的超弹层与弹塑性层两层叠置而成。两层结构有相同的加载力学行为，表现为线弹性、屈服平台与压实三个阶段，但两层呈现不同的卸载性能。超弹层按照MULLINS效应规律进行卸载，弹塑性层按照线弹性力学行为进行卸载。然后基于EPS的单轴压缩试验结果，获得了超弹层与弹塑性层本构模型中9个参数的结果，这些参数能够同时表征非线性卸载与残余变形力学行为。最后利用两层的本构模型预测了EPS连续多次(3次)冲击动力学响应，试验结果与理论计算结果良好的吻合性证实了本文所提出的方法的有效性。
关键词：非线性卸载；残余变形；超弹本构；弹塑性本构；连续多次冲击
Abstract
A simple method is presented to characterize the nonlinear unloading and residual deformation behavior of foams. Combined with hyperelastic constitutive model and elastoplastic constitutive model, plastic foam is considered to be composed of two layers of hyperlastic layer and elastic plastic layer from the same cross-sectional area but different thickness. The two layers have the same loading behavior, which are linear elasticity, yield platform and compaction. However, the unloading performances of the two layers are different, while hyperelastic layer is unloaded according to the Mullins effect law, and the elastic-plastic layer is unloaded according to the linear elastic mechanical behavior, respectively. Then, based on the results of EPS uniaxial compression test, the results of 9 parameters in the constitutive model of hyperelastic layer and elastic-plastic layer are obtained. These parameters can simultaneously characterize the mechanical behavior of nonlinear unloading and residual deformation. Finally, the dynamic response of EPS is predicted by using two-layer constitutive model. The experimental results are consistent with the theoretical results to confirm the effectiveness of the proposed method.
Key words: nonlinear unloading; residual deformation; hyperelastic constitutive; elastoplastic constitutive; consecutive multiple impacts
关键词
非线性卸载 /
残余变形 /
超弹本构 /
弹塑性本构 /
连续多次冲击
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Key words
nonlinear unloading /
residual deformation /
hyperelastic constitutive /
elastoplastic constitutive /
consecutive multiple impacts
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