摘要
密封圈在固体火箭发动机点火升压阶段承受燃气高速冲击载荷,其力学响应与准静态存在较大差异。采用分离式霍普金森压杆(SHPB)装置进行了硅橡胶单轴压缩实验,得到其在应变率2100~5000 s^(-1)范围内的压缩实验数据;分别采用两参数Mooney-Rivlin(M-R)超弹模型和朱-王-唐(Z-W-T)高应变率松弛响应项来修正Johnson-Cook(JC)模型的非线性平衡项和黏弹性响应项,建立高应变率下硅橡胶黏-超弹修正JC模型。结果表明,硅橡胶动态压缩力学性能表现出明显率相关性且远高于准静态;高应变率下,其初始弹性模量和动态屈服强度随应变率的增加而增大,峰值应变随应变率呈现线性增长趋势,峰值应力则呈现幂率增长趋势;修正JC模型拟合结果与实验结果重合度较高,但是由于所建本构模型未考虑热软化效应,在应变率6000 s^(-1)下,大变形预测结果高于实验结果。
The sealing ring is subjected to high-speed impact load of gas in the ignition and pressurization of solid rocket motor,and its mechanical response is quite different from that of quasi-static state.Therefore,the uniaxial compression experiment of silicone rubber was carried out by using the split Hopkinson pressure bar(SHPB)device,and the compression experimental data in the strain rate range of 2100~5000 s^(-1) were obtained.The two-parameter Mooney-Rivlin(M-R)hyperelastic model and Zhu-Wang-Tang(Z-W-T)high strain rate relaxation response term were used to modify the nonlinear equilibrium term and viscoelastic response term of the Johnson-Cook(JC)model,respectively.The visco-hyperelastic modified JC model of silicone rubber under high strain rate was established.The results show that the dynamic compressive mechanical properties of silicone rubber show obvious rate dependence and are much higher than quasi-static ones.At high strain rates,the initial elastic modulus and dynamic yield strength of silicone rubber increase with the increase of strain rate,the peak strain increases linearly with the strain rate,and the peak stress increases exponentially with the strain rate.The fitting results of the modified JC model are in good agreement with the experimental results.However,because the constitutive model does not consider the thermal softening effect,the prediction results of large deformation are higher than the experimental results at the strain rate of 6000 s^(-1).
作者
吴坤澳
沙宝林
张镇国
王江涛
侯晓
尤军峰
WU Kunao;SHA Baolin;ZHANG Zhenguo;WANG Jiangtao;HOU Xiao;YOU Junfeng(The Xi'an Institute of Aerospace Solid Propulsion Technology,Xi'an 710025,China;School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;China Aerospace Science and Technology Corporation,Beijing 100048,China)
出处
《固体火箭技术》
北大核心
2025年第6期905-911,共7页
Journal of Solid Rocket Technology
