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| 用圆孔内单边裂纹平台巴西圆盘和实验-数值-解析法确定砂岩的动态起裂和扩展韧度 | |
| 引用本文： | 周妍,张财贵,王启智. 用圆孔内单边裂纹平台巴西圆盘和实验-数值-解析法确定砂岩的动态起裂和扩展韧度[J]. 振动与冲击, 2017, 36(5): 37-47 |
| 作者姓名： | 周妍 张财贵 王启智 |
| 作者单位： | 1.四川大学 土木工程及应用力学系，成都 610065； 2.湖南工学院 建筑工程与艺术设计学院，衡阳 421000; 3. 水力学及山区河流开发保护国家重点实验室，成都 610065 |
| 摘 要： | 在I型(张开型)动态断裂实验中,利用大直径(?100 mm)分离式霍普金森压杆径向冲击圆孔内单边裂纹平台巴西圆盘试样。考虑了材料惯性效应和裂纹扩展速度对动态应力强度因子的影响,用实验-数值-解析法确定了高加载率和高裂纹扩展速度情况下,砂岩的动态起裂韧度和动态扩展韧度。由动态实验获取试样的动荷载历程,采用裂纹扩展计(Crack Propagation Gauge,CPG)测定试样断裂时刻和裂纹扩展速度,获得裂纹扩展速度对应的普适函数值。然后将动荷载历程带入到有限元软件中进行动态数值模拟,求出静止裂纹的动态应力强度因子历程,再用普适函数值对其进行近似修正。最后根据试样的起裂时刻和穿过CPG中点的时刻,由相应的动态应力强度因子历程分别确定砂岩的动态起裂和动态扩展韧度,它们分别随动态加载率和裂纹扩展速度的提高而增加。 |
| 关 键 词： | 圆孔内单边裂纹平台巴西圆盘 实验-数值-解析法 动态起裂韧度 动态扩展韧度 裂纹扩展计 普适函数 |
Determination of dynamic initiation toughness and dynamic propagation toughness of sandstone |
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| ZHOU Yan,ZHANG Caigui,WANG Qizhi,. Determination of dynamic initiation toughness and dynamic propagation toughness of sandstone[J]. Journal of Vibration and Shock, 2017, 36(5): 37-47 | |
| Authors: | ZHOU Yan ZHANG Caigui WANG Qizhi |
| Affiliation: | 1.Department of Civil Engineering and Applied Mechanics,University of Sichuan,Chengdu 610065,China; 2.School of Architectural Engineering and Art Design,Hunan Institute of Technology,Hengyang 421000;3.State Key Laboratory of Hydraulics and Mountain River Engineering,Chengdu 610065,China |
| Abstract: | The opening-mode dynamic fracture test was conducted with sandstone specimens of holed single cracked flattened Brazilian disc,they were impacted with a large-diameter (100 mm) split Hopkinson pressure bar.Considering influences of material inertia effect and crack propagation velocity on the dynamic stress intensity factor,an experiment-numerical-analytical method was used to obtain the dynamic initiation toughness of sandstone under different dynamic loading rates,and the dynamic propagation toughness of sandstone at different crack propagating velocities.Firstly,dynamic loading histories of specimens were obtained in dynamic tests.The crack initiation instant and crack propagating velocity of a specimen were sequentially measured with a crack propagation gauge (CPG).The universal function value corresponding to the crack propagating velocity was obtained.Then,the dynamic numerical simulation was conducted using a finite element software and taking the dynamic loading histories as inputs to obtain the dynamic stress intensity factor histories of a static crack,they were modified with the corresponding universal function value.Finally,according to the crack initiation instant and the instant crossing the middle point of the CPG,the dynamic initiation toughness and the dynamic propagation toughness were determined with the corresponding histories of the dynamic stress intensity factor.It was shown that the dynamic initiation toughness of sandstone increases with increase in dynamic loading rate,and the dynamic propagation toughness of sandstone increases with increase in crack propagation speed. |
| Keywords: | holed single cracked flattened Brazilian discexperimental-numerical-analytical methoddynamic initiation toughnessdynamic propagation toughnesscrack propagation gaugeuniversal function |
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