Damage constitutive model of rock subjected to coupled static loadings and cyclic impacts
HE Cong;JIN Jiefang;ZHOU Xuejin;CHENG Yun;CHANG Xiaoxu;YUAN Wei;School of Architectural and Surveying Engineering, Jiangxi University of Science and Technology;
Establishing a suitable damage constitutive model of rock is of great significance to study the dynamic mechanical characteristics of rock subjected to coupled static loadings and cyclic impacts. Firstly, the parameter of cyclic impact times was introduced to the damage constitutive relation of rock with the relation-ship between the elastic modulus of rock and the accumulative damage variable which based on the evolution model of damage accumulation of rock subjected to coupled static loadings and cyclic impacts. Secondly, com-bining the statistic damage model and visco-elastic model, a rock dynamic damage constitutive model was es-tablished under the axial pressure and the confining pressure and cyclic impacts based on the Drucker-Prager failure criterion with the assumption that the rock micro unit strength complied with the Weibull distribution.Then, the experimental data with coupled static and dynamic loadings on rock was used to verify the correct-ness and feasibility of the damage constitutive model. Finally, the influence law of parameters to the stress-strain curve was studied in the process of cycle impact in the model. The results show that there is a good co-herence between the established damage constitutive model of rock and the experimental data, which can also reflect a constitutive relation of rock subjected to coupled static loadings and cyclic impacts. The parameters of elastic modulus and viscosity coefficient of rock have a great influence on the stress-strain curve in the pro-cess of cycle impact, but the parameters of friction angle and Poisson's ratio of rock have little influence on the impact of fatigue stress-strain curve of rock which is under 3D static loadings. In the process of cycle im-pact, the non-uniformity of rock gradually increases. The results are beneficial to improve the dynamic fatigue mechanics theory system of rock subjected to coupled static loadings and cyclic impacts.
【Fund】： 国家自然科学基金资助项目(51104068);; 江西省教育厅科技研究项目(GJJ13406);; 国家级大学生创新训练项目(GZG-12-08-20)
【CateGory Index】： TU45
【CateGory Index】： TU45