混凝土主动围压SHPB试验波形数值分析  

Numerical Analysis on Waveforms in Split Hopkinson Pressure Bar Tests of Concrete under Active Confining Pressures

作　　者：袁伟[1] 金解放[1] 梁晨[1] 王杰[1] 程昀[1] 何聪[1] 郭钟群[1] YUAN Wei;JIN Jie-fang;LIANG Chen;WANG Jie;CHENG Yun;HE Cong;GUO Zhong-qun(School of Architectural and Surveying&Mapping Engineering,Jiangxi University of Science and Technology, Ganzhou 341000,China)

机构地区：[1]江西理工大学建筑与测绘工程学院,江西赣州341000

出　　处：《长江科学院院报》2018年第7期141-146,共6页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(51664017);江西省教育厅科技项目(GJJ160616;GJJ14462);江西理工大学科研基金项目(NSFJ2014-G04)

摘　　要：为探究主动围压SHPB(分离式霍普金森压杆)试验中反射波形与混凝土动态响应的关系,采用LS-DYNA软件,基于H-J-C本构模型,模拟了混凝土的主动围压SHPB试验,从波形特征的变化分析了围压对混凝土动态力学性质的影响。结果表明:围压条件下混凝土的破坏形式为压剪破坏,试件的平均损伤度随围压的增大而降低。试验中反射波具有"双峰"特性,且围压对第二峰值应力的影响较大,其值随着围压的增大而减小,表征了试件的变形破坏程度;而第一峰值应力几乎不受围压的影响,其主要与冲击波的幅值有关;反射波尾存在压缩波段,该段的峰值应力随着围压的增大逐渐增大,表征了围压下试件的完整性比较好,且其变形能力和残余承载力均有所提高。研究结果可为评估三轴应力下混凝土构件的动态损伤和残余承载力提供参考。In an attempt to explore the relationship between dynamic response of concrete and waveform of reflected waves during Split Hopkinson Pressure Bar(SHPB)tests under confining pressure,we simulated the SHPB tests under active confining pressure using LS-DYNA based on the Johnson-Holmquist Concrete constitutive model.We also analyzed the influence of confining pressure on dynamic properties of concrete in terms of changes in waveform characteristics.Results show that the failure mode of concrete under confining pressure is compression-shear failure,and the average degree of damage decreases with the climbing of confining pressure.The reflected wave in SHPB test is featured with double peaks,of which the first peak stress is barely affected by confining pressure,but by the magnitude of impact wave;while the second peak stress is significantly affected by confining pressure,declining with the increase of confining pressure,which implies the deformation degree of specimens.Compressive wave was found in the end of the reflected wave;with the increase of confining pressure,peak stress of the compressive wave increased as well,indicating an enhancement in deformation capacity and residual bearing capacity of the concrete specimen.The research achievements could serve as a reference for evaluating the dynamic damage and residual bearing capacity of concretes under triaxial stress.

关 键 词：混凝土 SHPB试验 主动围压 损伤度 “双峰”特性 压缩波 

分 类 号：TU502.6[建筑科学—建筑技术科学]