HTPB推进剂高应变率粘弹性本构模型研究

High Strain-Rate Viscoelastic Constitutive Model for HTPB Propellant

关键词:  HTPB推进剂  高应变率  本构模型  分离式Hopkinson压杆  温度效应 

Key words:  HTPB (hydroxy-terminated polybutadiene binder) propellant  High strain-rate  Constitutive model  Split Hopkinson pressure bar  Temperature effect

摘要:

为分析HTPB推进剂在高应变率条件下的力学响应,开展了推进剂分离式Hopkinson压杆(SHPB)实验,得到了不同温度(-40~25℃)和应变率(700~2050s-1)下的应力-应变曲线。结果表明,HTPB推进剂在高应变率条件下具有显著的温度和应变率敏感性,且随着应变率的增加和温度的降低,推进剂的应力逐渐增加。在Burke模型基础上,结合超弹性和粘弹性理论,建立了一种考虑温度和高应变率效应的本构模型。通过不同温度和应变率条件下实验结果与本构理论预测对比,验证了本构模型的有效性,可为固体推进剂药柱点火瞬态结构完整性分析提供理论依据。 

Abstract:

In order to research mechanical behaviors of HTPB propellant at high strain-rate, split Hopkinson pressure bar(SHPB) tests at different temperature(-40~25℃) and strain rate (700~2050s-1) were conducted and stress-strain curves were obtained. The results show that the mechanical properties of HTPB propellant are sensitive to temperature and strain rate, and stress increases gradually with decreasing temperature and increasing strain rate. Based on Burke model, a constitutive model that incorporates nonlinear hyperelastic and viscoelastic material response for HTPB propellant was developed for high strain-rate impact loading conditions. Predictions of the stress-strain response were made using the constitutive model. The good agreement between the predicted and the experimental results indicates the validity of constitutive model for different temperature and high strain-rate. The constitutive model can provide the theoretical basis for structural integrity of solid propellant grain under ignition transient pressure loading.