摘要
采用数字激光动态焦散线试验系统,利用落锤冲击含预制裂纹(倾斜角度分别为0°,30°,45°)的缺陷介质,研究裂纹扩展的动态行为。结果表明:冲击荷载下,裂纹会于预制裂纹一端起裂,扩展至整个试件,且扩展路径指向重锤落点;主裂纹尖端的动态应力强度因子振荡增大又减小,然后增大至最大值时主裂纹起裂;次裂纹起裂前,d?K振荡变化,起裂后迅速增大后振荡减小;主裂纹起裂后,速度迅速减小;次裂纹扩展速度先增大后振荡减小,与Kd的变化趋势保持一致;含缺陷的冲击断裂试验中,主裂纹起裂时间较晚。
The dynamic behavior of crack propagation due to the impacting of drop hammer on the defective medium of manufactured crack（inclination angle, respectively, for the 0°, 30°, 45°） was analyzed using the test system of digital laser dynamic caustics（DLDC）. Under the action of the impact loading, the cracks started from one side of the existing crack, then extended to the whole specimen, and the path pointed to the contact point of drop hammer. K1d of the main crack oscillated till the occurring of the first peak. It decreased and then increased to the maximum value when the main crack began to propagate. K1d of the wing crack oscillated before propagation, then quickly increased to the maximum value and decreased thereafter. The velocity of the main crack decreased quickly after propagation. The main crack initiation delayed.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第10期1971-1976,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金–煤炭联合基金重点项目(51134025)
高等学校博士学科点专项科研基金项目(新教师类)(20120023120020)
博士研究生拔尖创新人才培育基金项目(800015Z645)
关键词
爆炸力学
冲击荷载
缺陷介质
动态焦散线
数字激光
blasting mechanics
impact loading
defective medium
dynamic caustics
digital laser
