冲击加载下板岩压缩破坏层理效应及损伤本构模型研究  

Study on bedding effect and damage constitutive model of slate under compressive dynamic loading

作　　者：欧雪峰 张学民[2] 张聪[2] 冯涵[2] 周贤舜[2] 赵虹 OU Xuefeng;ZHANG Xuemin;ZHANG Cong;FENG Han;ZHOU Xianshun;ZHAO Hong(School of Civil Engineering,Changsha University of Science and Technology,Changsha,Hunan 410114,China;School of Civil Engineering,Central South University,Changsha,Hunan 410075,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《岩石力学与工程学报》2019年第S02期3503-3511,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51378505)。

摘　　要：为探究动态加载条件下层状板岩的各向异性行为,采用分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)获得江西层状板岩在高应变率下5组层理面倾角(θ=0°,30°,45°,60°和90°)临界破坏状态力学特征及破坏机制,进而利用元件组合模型理论,建立考虑宏观层理影响的层状岩体动态损伤本构模型。试验及理论分析结果表明:各层理角度试样应力-应变曲线峰值大小不同,但总体变化规律相近,均包含加载前期的弹性压缩阶段,中期的塑形阶段和塑性加强阶段,以及达到峰值后的峰后曲线;临界破坏状态下层理面在试样的破坏中起到重要作用,除θ=0°为穿越层理面的劈裂破坏外,其余层理倾角的破坏模式主要包括:偏向层理面方向的剪切破坏、沿层理面的滑移破坏和沿层理面的劈裂破坏。新建立的层状岩体动态损伤本构模型,综合考虑岩体自身微观损伤和宏观层理面损伤叠加影响,该模型不仅能较好地描述冲击条件下层状岩体应力-应变曲线变化规律,且峰值强度吻合较好,有助于更为准确地描述层状板岩在高应变率下变形破坏行为。To investigate the anisotropic behaviour of layered slate under dynamic loadings,five groups of dip angles(θ=0°,30°,45°,60°and 90°)of layered slate in Jiangxi Province were tested by the split Hopkinson pressure bar(SHPB).The critical failure mechanical characteristics and failure mechanism of the slate under high strain rates were demonstrated.In addition,a damage constitutive model was established by the component combination model theory,which considers the damage of macroscopic layers.Both experimental and theoretical results illustrates that the peak values of stress-strain curves are different under different dip angles,but the overall trends are similar,including both elastic compression stage,plastic stage,plastic strengthening stage and post-peak curve after reaching the peak value.The bedding plane plays significant role in the failure of the slate except for the case withθ=0°.The main failure modes are mainly composed by splitting failure through the bedding,shear failure in the bedding direction,slip failure and splitting failure along the bedding.The dynamic damage constitutive models of layered rock mass take the superposition effect of micro-damage and macro-damage of layered rock mass into consideration.Comparing the predicted results with the experimental results,the proposed model can describe the variation of stress-strain curve of layered rock mass under dynamic loadings,and more importantly it agrees well with the peak strength,which is helpful to accurately demonstrate the deformations and failure behaviors of layered slate under high strain rates.

关 键 词：岩石力学 层状板岩 高应变率 损伤 本构模型 

分 类 号：TU45[建筑科学—岩土工程]