Caustic study on blast-induced wing crack behaviors in dynamic–static superimposed stress field  

作　　者：Yang Liyun Yang Renshu Qu Guanglong Zhang Yufei 

机构地区：[1]School of Mechanics & Civil Engineering, China University of Mining & Technology

出　　处：《International Journal of Mining Science and Technology》2014年第4期417-423,共7页矿业科学技术学报（英文版）

基　　金：the financial support received from the PhD Programs Foundation of Ministry of Education of China (No. 20120023120020);the National Natural Science Foundation of China (No. 51134025)

摘　　要：This paper studies blast-induced wing crack behavior in a dynamic–static superimposed stress field using high-speed photography in combination with the optical method of caustics. With a static–dynamic loading setup, four PMMA plate specimens with pre-existing cracks under different static loading and the same dynamic loading were tested to observe the mechanical characteristics and the kinematic characteristics of blast-induced wing cracks during the propagation process, including crack length, crack velocity and dynamic stress intensity factor(SIF) at the crack tip. The results show that the behavior of the blast-induced wing crack is affected by the explosion stress wave and initial static stress, and the initial static stress with the direction being perpendicular to the wing crack propagation direction hinders crack propagation. Furthermore, the boundary constraint condition of the specimen plays an important role on the behavior of the crack propagation in the experiment.This paper studies blast-induced wing crack behavior in a dynamic-static superimposed stress field using high-speed photography in combination with the optical method of caustics. With a static-dynamic loading setup, four PMMA plate specimens with pre-existing cracks under different static loading and the same dynamic loading were tested to observe the mechanical characteristics and the kinematic char- acteristics of blast-induced wing cracks during the propagation process, including crack length, crack velocity and dynamic stress intensity factor （SIF） at the crack tip. The results show that the behavior of the blast-induced wing crack is affected by the explosion stress wave and initial static stress, and the initial static stress with the direction being perpendicular to the wing crack propagation direction hinders crack propagation. Furthermore, the boundary constraint condition of the specimen plays an important role on the behavior of the crack propagation in the experiment.

关 键 词：Dynamic-static superimposed stress field Blast-induced wing crackPre-existing crackCaustics 

分 类 号：TD235[矿业工程—矿井建设]