为建立丁腈橡胶一类高分子聚合物在大范围应变率加载条件下的本构模型，本文采用超弹性-粘弹性模型描述丁腈橡胶的力学特性，通过低应变率拉压试验、中应变率动态扫频试验、高应变率SHPB冲击试验获取丁腈橡胶材料应力应变、储能模量和损耗模量数据。使用遗传算法对不同试验数据与理论值误差的平方和函数进行优化，获得了5阶Prony级数描述的粘弹性模型，分析了Prony级数阶数对拟合效果的影响规律。以某型船用减振器为对象，通过试验获取其静态刚度、动态刚度和阻尼比、冲击刚度，并在ABAQUS中进行相同工况的仿真，仿真刚度及阻尼比误差均小于10%。结果表明：同时考虑不同应变率工况下的多种试验数据，采用遗传算法优化获得的丁腈橡胶材料本构模型，能够在大范围应变率加载条件下描述橡胶的弹性及阻尼比。

In order to obtain the constitutive model of a class of polymer such as nitrile butadiene rubber under the condition of a wide range of strain rates, to accurately describe the stiffness characteristics and damping dissipation characteristics, the constitutive parameters of nitrile butadiene rubber were fitted by genetic algorithm. In this paper, the stress-strain data of static uniaxial test were used to fit the hyperelastic parameters. The energy storage modulus and loss modulus data of loading frequency within 50Hz were obtained by dynamic sweep test; Stress-strain data at different strain rates were obtained by Hopkinson pressure bar test. Combined with different experimental data, a Prony series viscoelastic model with the error weighted sum of squares of theoretical and experimental values as fitness function was established by genetic algorithm, and the number of Prony series order on fitting effect was analyzed. Finally, the results of nitrile butadiene rubber shock absorber under static test, dynamic test and drop hammer impact test are compared with the finite element simulation results to verify the accuracy of the constitutive model. The results show that the dynamic sweep frequency test and Hopkinson pressure bar test data can be used to fit the viscoelastic parameters of nitrile butadiene rubber, and the constitutive model described by the 5-order Prony series viscoelastic and hyperelastic can be obtained. This model not only has a unified constitutive model expression under a wide range of strain rate loading conditions, but also can accurately describe the stiffness hardening characteristics with the increase of strain rate and the damping dissipation capacity under dynamic loading. Based on the constitutive model established by this method, the error between the simulation stiffness value and the corresponding test stiffness value under static, dynamic and impact conditions is less than 10%. The damping coefficient error is less than 10%.

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