一种描述胶凝原油蠕变全程的损伤模型

摘要

根据统计力学原理,将连续损伤因子引入到虎克体中,得到与损伤耦合的非线性虎克体的本构方程,将得到的非线性虎克体模型与含有塑性体的NVPB模型串联,得到一个新的描述胶凝原油加速蠕变阶段的模型,编制拟合函数对试验数据进行拟合.对不同结构强度的胶凝原油蠕变过程进行拟合,分析模型中参数的变化规律及其实际物理意义.结果表明:该模型可以较为精确地描述胶凝原油非线性黏弹塑性剪切流变全程曲线；新模型结构简单、物理意义明确、精度高.%Based on statistical mechanics, continuous damage factor was introduced to elastic element to deduce a constitutive equation of nonlinear elastic element coupling the damage, then the nonlinear elastic element was integrated with the nonlinear viscoplastic body (NVPB) model to establish a new rheological model for gelled crude oils. The model could well describe the accelerating creep stage. A function was complied to fit the experimental data. The creep process of gelled crude oils with different structure strength was fitted. The change rules of the model parameters were analyzed to verify the actual physical meaning of the parameters. The results show that the model could fully describe the whole creep process of gelled crude oils precisely. The new model has simple structure, clear physical meaning and high precision.