Rock and Soil Mechanics ›› 2021, Vol. 42 ›› Issue (5): 1210-1220.doi: 10.16285/j.rsm.2020.6091

Previous Articles     Next Articles

Rock plastic-damage constitutive model based on energy dissipation

MA Qiu-feng1, LIU Zhi-he1, QIN Yue-ping2, TIAN Jing3, WANG Shu-li1   

  1. 1. School of Resources and Environmental Engineering, Shandong University of Technology, Zibo, Shandong 255000, China 2. School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China 3. Department of Mechanical Engineering, Zikuang University, 255120, Zibo, Shandong 255120, China
  • Online:2021-05-11 Published:2021-09-16
  • About author:MA Qiu-feng, male, born in 1990, PhD candidate, Lecturer, mainly engaged in research on rock mechanics and numerical calculation.
  • Supported by:
    the Youth Foundation of National Natural Science Foundation of China (51904177) and the National Natural Science Foundation of China (50904071).

Abstract: In this paper, the dissipative energy in the damage process was employed to solve the damage variable while the damage constitutive model was established. In this model, the Mohr-Coulomb criterion and the energy dissipation theory were introduced. Considering the hardening and softening characteristics of rock during loading, the non-associated plastic flow rule was applied to describe the plastic deformation of rock, and the damage variable was calculated by quoting the dissipation energy and damage energy dissipation rate in the damage process. Based on the conventional triaxial loading-unloading experiments, the energy consumption and damage evolution law of rock was analyzed. The expression of damage energy dissipation rate was established, and the parameters in the model were calibrated. Simulation was conducted by this model and the simulation results were compared with the experimental results to validate the model. In this process, the following conclusions were obtained: (1) in the elastic stage, the damage dissipation energy increases slowly with the axial strain, showing an upward concave curve, and the growth rate reaches the maximum near the peak-stress. In the residual stage, the relationship between damage dissipation energy and axial strain is linear; (2) based on elastic modulus associated damage definition, the experimental results show that there is a damage variable limit less than 1, and the damage variable limit gradually decreases with the increase of confining pressure; (3) the model in this paper can be used to investigate the strength, hardening, softening characteristics and strain law of rock under different confining pressures during the loading process. The numerical simulation results can describe the stress-strain relationship and damage evolution law of rock.

Key words: damage, energy dissipation, Mohr-Coulomb criterion, constitutive model, damage energy consumption rate