HTPB推进剂宽泛应变率下粘弹性本构模型研究

为研究HTPB推进剂的率相关性力学性能,采用材料万能试验机、液压试验机和分离式霍普金森压杆(SHPB),分别开展了低(1.67×10~(-4)~1.67×10~(-1)s~(-1))、中(1~100 s~(-1))、高(700~2 500 s~(-1))应变率的单轴压缩实验。实验结果表明,HTPB推进剂的压缩力学性能是率相关性,随应变率的升高,给定应变下的应力逐渐增大。采用广义非线性ZWT本构模型描述HTPB推进剂宽泛应变率下的压缩力学行为,模型预测与实验数据对比表明,模型中至少需要4个麦克斯韦元件。

Research on the viscoelastic constitutive model of HTPB propellant over a wide range of strain rates

To investigate the rate-dependent mechanical properties of hydroxyl-terminated polybutadiene ( HTPB) propellant, low(1.67×10-4~1.67×10-1 s-1), intermediate(1~100 s-1),and high strain rate (700~2500 s-1) compressive testing was per-formed,by using a universal testing machine,a hydraulic testing machine,and a split Hopkinson pressure bar ( SHPB) system,re-spectively. Results indicate that the compressive mechanical properties of HTPB propellant are rate-dependent and the stress at a given strain increases with an increase in strain rate. Generalized nonlinear ZWT model was employed to describe the compressive mechanical behaviours of HTPB propellant over a wide range of strain rates.Compasrison of the predicted values from the model and the experimental data shows that the number of Maxwell elements in the model should be at least 4.