Experimental study on damage characteristics of coal sample by shock wave impact

Abstract

On the basis of designing and transforming the bench shock tube in the laboratory, a test system for coal sample damage and destruction under shock pressure was built, and shock step pressure characteristics under different driving gas conditions and different pressures, with or without bedding structure and different bedding structures were studied. The results show that: CO2 and air have obvious internal damage effect and similar damage degree at the same pressure; under different shock wave incident pressures, the damage degree of briquette without bedding structure increases with the increase of incident pressure; compared with the impact strength of briquette coal samples without bedding structure and the serious degree of destruction of the dense structure inside the coal samples, the degree of damage of the coal samples of any bedding structure changes little; the vertical bedding and parallel bedding raw coal samples show good consistency at medium and high-speed jet pressure impacts. At low speeds, parallel bedding is less resistant to compression than vertical bedding.

Keywords

• shock tube
• ultrasonic testing
• bedding structure
• damage and destruction
• fracturing and permeability improvement