基于蠕变全过程的广义凯尔文体力学损伤模型改进与验证

(1.西安科技大学 能源学院,陕西 西安 710054; 2.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054; 3.国土资源部煤炭资源勘查与综合利用重点实验室,陕西 西安 710021)

蠕变; 改进广义凯尔文体; 损伤; 非线性拟合

Improvement and verification of generalized Kelvin damage model based on the whole creep process
CUI Feng1,2,3,MA Cheng-wei1

(1.College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China; 3.Key Laboratory of Coal Resource Exploration and Comprehensive Utilization,Ministry of Land and Resources,Xi'an 710021,China)

creep; damaged model" target="_blank"> improved generalized Kelvin damaged model; damage; nonlinear fitting

备注

岩石的蠕变在岩石力学研究中至关重要,岩石的蠕变表现出明显的阶段性。为了完整准确地描述岩石蠕变的全过程,在广义凯尔文模型的基础上定义了一个作用函数,串联一个非线性粘性原件并引入损伤因子,分别描述稳定蠕变和加速蠕变阶段,建立了广义凯尔文体力学损伤模型。利用Origin软件对绿片岩和盐岩的蠕变曲线进行分段拟合,并将实际蠕变曲线和改进后模型计算值进行比较。结果 表明:岩石的损伤会加快岩石在加速蠕变阶段的变形,引入损伤因子之后,模型能较好的描述加速蠕变阶段的变形; 改进后考虑损伤的广义凯尔文体模型能完整描述蠕变全过程,新模型的计算值与实验值拟合程度较高,验证了模型的合理性。反映出改进后的模型对三轴压缩实验和单轴压缩实验均适用,并且适用于刻画高围压下的岩石蠕变变形。为岩石蠕变的研究提供了一种新的力学模型。

A vital subject in the study of rock mechanics,the creep of rockshows distinct phases.In order to describe the whole process precisely,an action function was definedbased on the generalized Kevin model,to show the stabilization creep phase,a nonlinear viscous element was connected in series and a damaged parameter was introduced to describe speedup creep phase; then,the generalized Kevin mechanical damage model was created.The model was verified by fitting the creep curve of greenschist specimens and rock salt specimens for every stage using Origin,and a comparative study was made of the actual creep curve and the calculated value of improved model.The results indicate that the damage will accelerate the creep in speedup creep phase,and the model can describe this stage well with the damaged parameter introduced; the improved generalized Kevin model considering damage can describe the whole creep,and the calculated value of new model fits well with the experimental value,indicating the rationality of new model.The examination shows that the improved model applies to triaxial compression testing and uniaxial compression testing,and it can also describe the rock creep under high confining pressure.Accordingly a new mechanical model for the further study of rock creep is provided.