时间⁃温度⁃应力等效原理在TATB基PBX拉伸蠕变中的适用性分析

Applicability Analysis of Time⁃temperature⁃stress Equivalent Principle in Tensile Creep of TATB⁃Based PBX

为验证时间‐温度‐应力原理在TATB基PBX拉伸蠕变中的适用性,实现长期拉伸蠕变变形评估计算,开展了某TATB基PBX恒应力不同温度的常规拉伸蠕变实验和恒温度梯级拉伸蠕变实验,采用陈氏法对梯级加载蠕变曲线进行分解处理,得到恒温度不同应力的拉伸蠕变曲线,基于非线性粘弹性材料的时间‐温度‐应力等效原理,采用二分法计算程序对各蠕变柔量曲线进行了平移汇集,获得了参考温度和应力(30℃、3.0 MPa)下的温度应力耦合蠕变柔量主曲线和考虑温度和应力的Williams‐Landel‐Ferry方程参数。结果表明在所分析的温度范围(30~50℃)和应力范围内(1.0~5.5 MPa),TATB基PBX的拉伸蠕变行为较好地符合时间‐温度‐应力等效原理描述,可以利用该原理通过高温度高应力的PBX短期拉伸蠕变实验预测其低温低应力的长期拉伸蠕变变形。

In order to verify the applicability of time-temperature-stress principle in tensile creep of TATB-based PBX and realize the evaluation calculation of long-term uniaxial tensile creep deformation,the conventional tensile creep experiment under constant stress but different temperatures and multistep tensile creep experiment under constant temperature of a TATB-based PBX were carried out.The tensile creep curves under constant temperature but different stresses were obtained by decomposing the multistep creep curve following Chen′s method.The coupled creep compliance master curves under reference temperature and stress(30℃and 3.0 MPa)and parameters of Willianms-Landel-Ferry equation considering temperature and stress were obtained by translating and assembling the creep compliance curves using dichotomy calculation program based on the time-temperature-stress equivalence of nonlinear viscoelastic materials.The results show that the tensile creep behavior of TATB-based PBX is well described by the time-temperature-stress equivalent principle in the analyzed temperature range from 30℃to 50℃and stress range from 1.0 MPa to 5.5 MPa,which could be used to predict the long-term tensile creep deformation under low temperature and low stress through the short-term tensile creep tests at high temperature and stress.