冲击作用下混凝土裂纹扩展试验研究及数值模拟  

Tests and simulation for concrete crack propagation under impact load

作　　者：张华[1] 郭继鑫 傅玉珍 高群[2] 王斌[1] 

机构地区：[1]河海大学土木与交通学院,南京210098 [2]江苏省建筑科学研究院有限公司,南京210098

出　　处：《振动与冲击》2016年第17期107-112,共6页Journal of Vibration and Shock

基　　金：中央高校基本科研业务费项目(2013B15714)

摘　　要：采用改进的分离式霍普金森杆(SHPB)分别对混凝土无切槽平台巴西圆盘FBD(Flattened Brazilian Disc)、直切槽平台巴西圆盘CSTFBD(Cracked Straight-Through Flattened Brazilian Disc)试件进行不同应变率的径向劈裂试验,得出无切槽平台巴西圆盘的劈裂拉伸应力-径向应变曲线,以及三种不同强度等级混凝土的动态弹性模量、峰值应力、峰值应变、拉伸敏感系数的应变率效应。此外,分析了不同角度预制裂纹对中心直裂纹巴西圆盘断裂韧性的影响以及复合裂纹的复合比与加载角度的关系。采用ABAQUS中的扩展有限元法对劈裂冲击试验中的直切槽平台巴西圆盘的破坏过程进行了模拟,并且对试件的裂纹扩展和破坏机理进行了分析,将数值模拟得到的结果与试验结果进行对比,得到主裂纹的扩展趋势是一致的。The radial spitting crack tests were conducted by using improved separated Hopkinson pressure bar（ SHPB） for a flattened Brazilian disc（ FBD） and a cracked straight through flattened Brazilian disc（ CSTFBD） under different stain rates. Splitting tensile stress-radial strain curves of the flattened Brazilian disc,and dynamic elastic modulus,peak stress,peak strain and tensile strain rate sensitive coefficient effects of concrete with three different strength grades were obtained. In addition,the influences of pre-crack with different angles on the fracture toughness of the cracked straight through flattened Brazilian disc and the relationship between composite ratio of mixed mode cracks and loading angle were analyzed. The crack propagation and failure mechanism were studied. The test results and those of numerical simulation with the extended FE method were compared. The results showed that the growth trends of cracks with tests are consistent with those of numerical simulation.

关 键 词：裂纹扩展 应变率 平台巴西圆盘 断裂韧性 HOPKINSON杆 

分 类 号：O348[理学—固体力学] TU528[理学—力学]