DLDC EXPERIMENT ON CRACK PROPAGATION IN DEFECTIVE MEDIUM UNDER IMPACT LOADING
YANG Renshu1，2，WANG Yanbing1，HOU Lidong1，YANG Liyun1
(1. School of Mechanics and Civil Engineering，China University of Mining and Technology，Beijing 100083，China；
2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，
Beijing 100083，China)
Abstract：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. 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. 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.
2014, Vol. 33 
