Journal of Changjiang River Scientific Research Institute ›› 2018, Vol. 35 ›› Issue (9): 127-132.DOI: 10.11988/ckyyb.20170333

• ROCK-SOIL ENGINEERING • Previous Articles     Next Articles

Fractional-order Visco-elasto-plastic Constitutive Model forRock under Cyclic Loading

LIU Han-qing1, PU Shao-yun1, LIU Xi-jin2, CHEN Ze-nan1, LI Qin1, HAO Zhi-cheng1, LI Lei1   

  1. 1.College of Civil Engineering, Guizhou University, Guiyang 550025;
    2.Department of Infrastructure and Planning, Beijing Jiaotong University, Beijing 100044, China
  • Received:2017-03-27 Published:2018-09-01 Online:2018-09-01

Abstract: In order to study the fatigue deformation characteristics of rock under cyclic loading, we established
one-dimensional and three-dimensional Fractional-order Visco-Elasto-Plastic Constitutive Model (FVEPCM) by replacing the common dashpot in viscoplastic body of Nishihara’s model with the fractional-order dashpot and connecting a viscous element in series in Nishihara’s model. Under high dynamic stress, the model is a FVEPCM reflecting the three states of rock fatigue deformation: deceleration stage, constant velocity stage, and acceleration stage; otherwise, it is a Burgers Model which reflects the two states of rock fatigue deformation: deceleration, and constant velocity stage. Fitting of the existing rock fatigue test results shows that the fatigue constitutive equation for rock based on FVEPCM can be used to better describe different deformation characteristics of rock under cyclic loading, and the effect of fitting to various types of deformation curves of rock is good, with the fitted correlation coefficients above 0.96.

Key words: rock mechanics, cyclic loading, fractional-order dashpot, Burgers Model, visco-elasto-plasticity, fatigue deformation

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