Abstract: In order to investigate the mechanical behavior of a new kind of filmy Ethylene- Propylene-Diene Monomer (EPDM) inhibitor，uniaxial tensile tests at different tensile rates (0.1～5mm/s) and multi-step relaxation test were conducted. The stress-strain response of this material was studied and a visco-hyperelastic constitutive model was developed under finite deformation. The model consists of two parts: a hyperelastic part derived from a polynomial strain energy density function and a viscoelastic part described by the Maxwell model. The viscoelastic parameters were obtained by the uniaxial tensile tests and the hyperelastic parameters were obtained by multi-step relaxation test. Comparisons were made between the predictions based on the proposed model and the test result in the range of 20% engineering strain. The results show that the maximum deviation between the predictions and the test result is only 5.6%，which confirms that the constitutive model can describe the mechanical properties of this material well.

Key words: EPDM rubber；Inhibitor；Visco-hyperelasticity；Constitutive model

摘要： 为了描述一种新型三元乙丙(EPDM)橡胶薄膜包覆材料的力学性能，进行了不同拉伸速率(0.1～5mm/s)下的单轴拉伸试验和多步松弛试验。研究了材料的应力-应变响应，建立了有限变形下的粘-超弹本构模型。模型由超弹与粘弹两部分组成:超弹部分基于多项式应变能函数推导获得，粘弹部分则采用Maxwell模型来描述。通过单轴拉伸试验和多步松弛试验分别获得粘弹参数和超弹参数。将所建模型预测结果与试验结果相对比。结果表明:模型能很好地描述材料在20%工程应变范围内的力学特性，预测结果与试验结果最大偏差仅为5.6%，验证了模型的可靠性。

关键词: 三元乙丙橡胶；包覆层；粘-超弹性；本构模型