摘要
利用爆炸加载数字激光动态焦散线试验系统,进行双孔爆破爆炸应力波作用下缺陷介质裂纹扩展试验。研究了含水平预制裂纹和竖直预制裂纹的介质裂纹扩展路径、速度、加速度和裂尖动态应力强度因子变化规律。试验结果表明:在爆炸应力波作用下,预制裂纹尖端起裂,并扩展。炸药爆炸后,主裂纹的扩展速度迅速达到峰值,之后开始振荡减小,其加速度呈现波浪起伏式的振荡变化。次裂纹起裂后速度增大至峰值,然后开始减小。主裂纹尖端的动态应力强度因子K_Ⅰ从峰值振荡减小,又振荡增加至第二个峰值,之后振荡减小。次裂纹尖端的动态应力强度因子K_Ⅰ达到最大时,次裂纹起裂,之后K_Ⅰ振荡减小。裂纹扩展的过程中K_Ⅱ基本都小于K_Ⅰ。
The experimental system of explosive load digital laser dynamic caustics was used to study the propa- gation behavior of cracks under the effect of explosive stress waves of double holes explosion. Meanwhile, the path, velocity and acceleration of the propagation of cracks in a Polymethyl methacrylate （PMMA） medium were also stud- ied ,including horizontal and vertical prefabricated cracks and the variation of dynamic stress intensity factor at the tip of the cracks. The experimental results show that the tip of the prefabricated cracks propagated under the effect of an explosive stress wave. After detonation, the velocity of the main crack rapidly peaked, then decreased in oscillation. After the secondary crack,its velocity peaked and then began to decrease. The dynamic stress intensity factor Kl at the main crackg tip decreased from the peak value in oscillation, and increased to the second peak value, then de- crease in oscillation. When the dynamic stress intensity factor K1 at the main crackg tip reached the maximum val- ue ,the secondary crack initiated ,and then Kl decreased in oscillation. In the process of crack propagation, the Ku was almost less than K1.
作者
王雁冰
商禹智
石震鑫
田秋实
王恒攀
张显裕
WANG Yan-bing , SHANG Yu-zhi , SHI Zhen-xin , TIAN Qiu-shi , WANG Heng-pan , ZHANG Xian-yu(School of Mechanics and Architecture Engineering, China University of Mining and Technology（ Beijing）, Beijing 100083, China)
出处
《爆破》
CSCD
北大核心
2018年第1期15-20,48,共7页
Blasting
基金
中国博士后科学基金面上项目(2016M600147)
国家留学基金建设高水平大学公派研究生项目
关键词
双孔爆破
缺陷介质
裂纹扩展
动焦散试验
动态应力强度因子
blasting of double holes
defective medium
crack propagation
caustics
dynamic stress intensity factor
