摘要
采用改进的SHPB试验装置,进行深部岩石的三维高静载频繁动态扰动试验,分析动态应力-应变曲线的一般特征,可将其细分为微裂纹稳定发展、微裂纹非稳定发展、疲劳损伤、疲劳破坏4个阶段进行描述,其中峰值后的2个阶段处于动态应力卸载过程。基于连续因子、应变等效原理及统计损伤理论定义岩石的损伤变量并推演损伤演化方程,采用组合模型法建立岩石的本构模型。结合试验数据,验证岩石的损伤演化规律及建立的本构模型,结果表明:利用推演的损伤演化方程计算出损伤变量,其与动态应变的关系曲线符合试验中岩样的损伤规律;建立本构方程的拟合曲线与试验曲线具有较好的一致性,说明建立的本构模型可以用来预测深部岩石处于三维高静载频繁动态扰动时的动力学特性。
Using a modified split Hopkinson pressure bar （SHPB）, the tests were conducted on deep rocks under three-dimensional （3D） high-static load and frequently dynamic disturbance. Then dynamic stress-strain curves were obtained for describing general features, which can be divided into four stages, namely, steady development of microcracks, non-stable development of microcracks, fatigue damage, and fatigue destruction. Particularly, two stages after the peak value were in the dynamic stress unloading process. Based on the continuous divisor, strain equivalent principle and statistic damage principle, a fatigue variable of rock was defined and a damage evolution equation was deduced. Then, a combination model was adopted to establish a damage constitutive model. Compared with testing data, a damage evolution law of rock and the established damage constitutive model were verified. The damage variable was also calculated using the deduced damage evolution equation. Experimental results show that the relevant curves between the damage variable and dynamic strain conform to damage law of rock samples. It is also found that the established fitting curves of constitutive equations show comparatively good agreement with experimental curves. Hence, it indicates that the established damage constitutive model can be used to predict dynamic mechanical characteristics of deep rock under 3D high-static load and frequently dynamic disturbance.
作者
王春
唐礼忠
程露萍
陈源
刘涛
韦永恒
WANG Chun TANG Li-zhong CHENG Lu-ping CHEN Yuan LIU Yao WEI Yong-heng(School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, China School of Resources ＆ Safety Engineering, Central South University, Changsha, Hunan, 410083, China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第8期2286-2296,2305,共12页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51474250)
国家重点基础研究发展计划(973)资助项目(No.2010CB732004)~~
关键词
深部岩石
三维高静载
频繁动态扰动
损伤特性
本构模型
deep earth rocks
3D high-static load
frequently dynamic disturbance
damage characteristics
constitutive model
