EXPERIMENTAL RESEARCH ON DAMPING PARAMETERS OF ROCK UNDER CYCLIC LOADING
LIU Jianfeng1，2，XU Jin1，2，LI Qingsong1，2，LI Ganglin1，2
(1. State Key Laboratory of Hydraulics and Mountain River Engineering，Sichuan University，Chengdu，Sichuan 610065，China； 2. School of Water Resources and Hydropower，Sichuan University，Chengdu，Sichuan 610065，China)
Abstract：Theoretical analysis of damping parameters of rocks is carried out；and the uniaxial cyclic loading tests for fine sandstone and silty mudstone are realized on MTS815 Flex Test GT rock mechanics test system. The sine wave is achieved in cyclic loading tests，and its frequency is 3 Hz. The cyclic number is 30 under dynamic stresses from 1.0 to 6.5 MPa. The method for testing damping parameters of rock by cyclic loading is provided；and some change characters between rock density and plastic deformation under cyclic loading and unloading are obtained together with the areas of hysteresis loops，damping ratios，damping coefficients，etc.. Under the same test conditions，it is found that the higher the rock density is，the smaller the plastic deformation between the hysteresis loops under cyclic loading and unloading tests is，and the denser the space of hysteresis loops is；conversely，the less the rock density is，the sparser the space of hysteresis loops is. With the rock density increasing，the area of hysteresis loops decreases，and the energy dissipation of rock is less；meanwhile，the area of hysteresis loops and the energy dissipation are larger. The results show that the damping ratio decreases，and the damping coefficient approximately increases with rock density increasing. Thus，it is possible to preliminarily estimate damping parameters according to rock density.
刘建锋,徐进,李青松,李刚林，. 循环荷载下岩石阻尼参数测试的试验研究[J]. 岩石力学与工程学报, 2010, 29(05): 1036-1041.
LIU Jianfeng1，2，XU Jin1，2，LI Qingsong1，2，LI Ganglin1，2. EXPERIMENTAL RESEARCH ON DAMPING PARAMETERS OF ROCK UNDER CYCLIC LOADING. , 2010, 29(05): 1036-1041.
