The mechanical behaviour of nitrate ester plasticized polyether (NEPE) in compressive tests performed under different strain rates was studied.A visco-hyperelastic constitutive equation in integral form was proposed to describe the finite-deformation response of incompressible NEPE at high strain rates.The equation comprises two parts:a component based on a strain energy density function expressed in polynomial form to characterize static hyperelastic behaviour,and the other in integral form to characterize dynamic viscoelastic behaviour.Established static and dynamic exprimental techniques are employed to determine four parameters in the constitutive relationship.Comparison of predictions based on the proposed model with experiments shows that the equation can be used to describe visco-hyperelastic behaviour of NEPE materials under high strain rates within 45％ of the engineering strain.%通过改进的分离式霍普金森装置,获得NEPE推进剂在高应变率下的力学曲线.结合超弹性和粘弹性理论,建立一种适合于描述不可压弹性体材料在高应变率有限变形下力学特性的积分型粘超弹本构模型.该模型由两部分组成:基于应变能函数的超弹部分及与应变率和松弛时间函数相关的积分型粘弹部分.其中,超弹部分描述材料在静态下力学特性,粘弹部分则主要用于表征材料动态响应.结合试验曲线获得模型中本构参数,并通过试验数据和模型预测结果对比证明,该模型可较好描述NEPE推进剂高应变率下45％工程应变量范围内的力学特性.
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