不同变形下的聚氨酯循环压缩力学性能的实验研究

Experimental study on the cyclic mechanical behavior of polyurethane at different compression strains

为了获取聚氨酯弹性体的循环压缩力学性能,通过开展聚氨酯弹性体在一系列不同最大压缩应变(10.1%、13.5%、17.5%、21.0%、30.0%)下的准静态循环压缩力学实验,获得了该类材料从小变形到中等变形范围的压缩加卸载应力-应变曲线;并基于实验结果探讨了该类材料的超弹性响应、残余应变、迟滞损耗和Mullins效应。采用经典的八链模型描述其超弹性力学特征,并利用线性模型描述其黏弹性力学特征,结合分子网络重构理论,建立了一个能准确描述聚氨酯循环加卸载力学行为的本构模型。结果表明,该本构模型可以较好地表征聚氨酯弹性体在不同应变和不同应变率下的实验结果,包括加卸载曲线、残余应变以及Mullins效应等。该模型有望为聚氨酯隔振器的力学行为预测提供参考。

In order to obtain the cyclic compression mechanical properties of polyurethane elastomers(PUE),a series of cyclic compression mechanical experiments of PUE under different moderate strains(10.1%,13.5%,17.5%,21.0%,30.0%)were carried out,and the compression stressstrain curves in the range of small to moderate strains were obtained.Based on the experimental results,the hyperelastic response,residual strain,hysteresis loss,and Mullins effect of the materials were discussed.The classical 8-chain model was used to describe the hyperelastic mechanical characteristics of PUE.The linear model was used to describe the viscoelastic mechanical characteristics.And combined with the theory of network alteration,a constitutive model was established which could accurately describe the cyclic loading and unloading mechanical behavior of PUE.The results show that the constitutive model can characterize the experimental results of PUE under different strains and different strain rates,including loading and unloading curves,residual strain,and Mullins effect,etc.It is expected to provide theoretical support for the prediction of mechanical behavior of polyurethane vibration isolators.