冲击载荷下岩石裂纹动态断裂参数研究  

The research of rock dynamic fracture parameter under the action of impact load

作　　者：宋义敏[1] 杨小彬[2] 杨晟萱 王乾[1] 

机构地区：[1]北方工业大学土木工程学院,北京100144 [2]中国矿业大学(北京)资源与环境工程学院,北京100083

出　　处：《采矿与安全工程学报》2015年第5期834-839,共6页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(51474013);国家"十二五"科技支撑计划项目(2012BAK09B06)

摘　　要：开展含I型预制裂纹的花岗岩矩形试件在冲击载荷作用下的动态断裂参数的试验研究。以自行研制的能实现中低冲击加载速度的可调速落锤冲击试验机进行加载,通过高速相机搭建数据采集系统进行数据采集,采用数字散斑相关方法对试验图像数据进行分析。对岩石I型裂纹在冲击载荷作用下的位移场演化特征、裂纹动态断裂的裂尖张开位移、裂纹扩展速度、动态断裂全过程中的裂尖应力强度因子等进行了定量研究。试验结果表明:落锤与岩石试件接触后,裂尖的应力强度因子呈增加趋势,当达到某一量值时,预制裂纹开裂,后续裂纹扩展的应力强度因子大于预制裂纹初始扩展的应力强度因子。An experimental research of rock dynamic fracture parameter under the action of impact load with the rectangular granite specimen with pre-cracks of Type I has been conducted. The test material is loaded by self-developed adjustable speed drop hammer impact tester which can realize low medium impact loading speed;the data is recorded by data collecting system set up by high-speed cameras, and the data of specimen surface speckles images in the dynamic fracture process of crack is analyzed by using digital speckle correlation method. The quantitative results of displacement field evolution, the dynamic fracture of crack tip opening displacement, the speed of the crack growth and stress intensity factor of the dynamic fracture have been obtained. The experimental results have shown that the crack tip stress intensity factor increases after drop hammer contacts with the rock specimen, and when the stress intensity factor reaches a certain value, the prefabricated crack initiation and subsequent stress intensity factor of crack initiation is greater than the initial crack stress intensity factor.

关 键 词：数字散斑相关方法 应力强度因子 裂纹扩展速度 岩石断裂 冲击载荷 

分 类 号：TD45[矿业工程—矿山机电]