Effect of impulse and bedding on impact toughness of coal

• Published in: Journal of coal science & engineering, China China, 2008-12, Vol.14 (4), p.628-630
• Main Author: 于永江 王来贵 李建新
• Format: Article
• Language: English
• Subjects: Earth and Environmental Science; Earth Sciences; Geochemistry; Geology; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Mechanical Engineering; 冲击动力学
• ISSN: 1006-9097; 1866-6566
• DOI: 10.1007/s12404-008-0427-0

In order to understand the properties of impact toughness of coal at different impact speeds, and the change of impact toughness of lump coal to joint directivity of lump coal, a series of impact tests were conducted on Beijing Da＇anshan Lump Coal at different impact speeds and in different impact direction. Through analyzing the test result, it is shown that the change of testing samples is similar when impact is exerted on the vertical bedding and the parallel bedding when the impulse is less than 20 N·s, and the difference increases with the impulse increasing when the impulse is more than 20 N·s. At the same time, the expanding energy of fracture in samples increases with its expanding speed, and the expanding energy of fracture has close relation with the impact direction of the tested samples. And the difference of impact toughness of lump coal produced by different impact direction increase with the impact speed. The fracture surface of lump coal when impact is exerted on the vertical bedding is smooth and the broken block number is fewer; but the fracture surface of lump coal when impact is exerted on the parallel bedding isn＇t smooth and the broken block number is more, which inflects impact toughness of coal is sensitive to some deficiency.