Acoustic emission parameters and energy dissipation law of cyclic load and unload damage of dihydrate gypsum under different loading rate  

作　　者：Yanyu Chu Gaofeng Ren Congrui Zhang Yin Zheng Dong Li 

机构地区：[1]School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan,China [2]China Academy of Safety Science and Technology,Beijing,China [3]Key Laboratory of Green Utilization of Key Non-metallic Mineral Resources,Ministry of Education,Wuhan,China [4]Key Laboratory of Mineral Resources Processing and Environment of Hubei Province,Wuhan University of Technology,Wuhan,China [5]CNBM Research Institute for Advanced Glass Materials Group Co.,Ltd,Bengbu,Anhui,China

出　　处：《Geohazard Mechanics》2023年第2期185-193,共9页岩土灾变力学（英文）

基　　金：support from the National Natural Science Foundation of China,grant number 52174087.

摘　　要：In order to explore the effect of loading rate on physical and mechanical properties of dihydrate gypsum,cyclic loading and unloading mechanical tests were carried out at different loading rates.Test results were analyzed from the aspects of stress-strain curve,energy distribution mode,damage law and failure mode of specimen.The main research results obtained in the thesis are as follows:with the increase of the loading rate,the peak value of specimen damage first increases rapidly,and then in-creases slowly,and there is a damage threshold.In the early stage of loading,the dissipated energy of the specimen accounts for about 70%of the total energy,most of the total energy input is converted into dissipated energy.The elastic energy density shows an increasing trend with the increase of the loading rate.The elastic energy density is the highest when the loading rate is 400 N/s,and more elastic energy can be stored.The ratio of elastic energy ue/u increases with the in-crease of loading rate and tends to be stable.The acoustic emission data show that the acoustic emission signals present a certain agglomeration phenomenon at the unloading point,and there is a“blank period”between the unloading point and the emergence of the next acoustic emission activity.In the early stage of specimen loading,friction-type acoustic emission is mainly generated.The cumulative ringing count when the load reaches the peak failure stress at low loading rate is more,indicating that low loading rate will produce more acoustic emission activities.With the increase of loading rate,the cumulative ringing number per unit time increases,indicating that the increase of loading rate accelerates the damage and failure of dihydrate gypsum near the peak value.The failure mode of gypsum specimens is shear failure,and the increase of loading rate of shear failure angle shows an increasing trend.The larger the loading rate is,the higher the strength of the specimen is.The more energy the press inputs during the loading process,the higher the ene

关 键 词：GYPSUM Energy densities Acoustic emission Ringing counts Energy storage limitation 

分 类 号：P55[天文地球—构造地质学]