聚氨酯缓冲材料瞬态响应特性研究

Investigation on transient response characteristics of polyurethane cushioning materials

为研究聚氨酯材料在动态载荷作用下的瞬态响应特性,开展了聚氨酯样件压缩实验,并利用实验数据分析校验了聚氨酯样件材料的Mooney-Rivlin应变能函数、Prony级数本构模型参数;然后采用有限元方法对聚氨酯缓冲材料的动态力学性能进行计算分析。研究结果表明:聚氨酯材料具有与超弹性相关的非线性出力特性和与粘弹性相关的迟滞效应,在不同速度的加载条件下,聚氨酯材料的力-位移响应曲线存在显著差异;在低速加载条件下,率相关的粘弹特性对曲线影响较小;提高加载速度,聚氨酯瞬时应变增大,率相关的粘弹特性对聚氨酯的响应影响更显著,使得响应曲线的斜率显著增加;在局部加载条件下,载荷与剪切力耦合作用,聚氨酯在压缩方向提供的支反力大小与受载区域的作用面积相关,面积越大,聚氨酯材料可提供的支反力就越大。

In order to study the transient response characteristics of polyurethane materials under dynamic loading,polyurethane sample compression experiments are carried out,and the Mooney-Rivlin strain energy function and Prony series constitutive model parameters of polyurethane sample materials are verified by experimental data analysis.Then,the finite element method is used to calculate and analyze the dynamic mechanical properties of the polyurethane cushion material.The results show that polyurethane materials have nonlinear output characteristics related to super elasticity and hysteresis effects related to viscoelasticity,and there are significant differences in the force-displacement response curve of polyurethane materials under low-speed and high-speed loading conditions.Under low-speed loading conditions,the viscoelastic properties of the rate correlation have less influence on the curve;Under high-speed loading conditions,the rate-dependent viscoelasticity characteristics significantly increase the slope of the response curve;Under local loading conditions,the load and shear force are coupled,and the size of the supporting force provided by the polyurethane in the compression direction is related to the area of action of the loaded area,and the larger the area,the greater the supporting force provided by the polyurethane material.