DYNAMIC CRITICAL CRACK TIP OPENING ANGLE OF ROCK UNDER MEDIUM-LOW LOADING SPEED
A photo-mechanics based method to measure the dynamic critical crack tip opening angle (CTOA) is proposed to evaluate the dynamic fracture toughness of rock. For measuring the dynamic critical CTOA under different loading speed, the three-point-bending granodioite specimen with a pre-existing crack is loaded by a speed-adjustable dropping hammer. The surface images of the specimen are captured using a high-speed camera and the displacement fields are then calculated using digital speckle correlation method (DSCM). The critical CTOA is then calculated using the proposed method based on the measured displacement fields. The dynamic critical CTOA of Fanshan granodioite is measured under the loading speed of 4.20~8.20 m/s. It is shown that the dynamic critical CTOA of the rock decreases with the increasing of the loading speed within this mediumlow speed range.
dynamic fracture toughness crack tip opening angle (CTOA) rock digital speckle correlation method (DSCM) loading speed
Shaopeng Ma Wenjing Guo Yimin Song Xiaobin Yang
Dept. of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 Dept. of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 School of Resources and Safety, China University of Mining & Technology, Beijing 100083 China
国际会议
广州
英文
234-239
2010-12-17（万方平台首次上网日期，不代表论文的发表时间）