Research on rigid-discrete coupling effect of scraper conveyor under different working conditions

As the key equipment of fully mechanized coal mining face, scraper conveyor undertakes the main task of coal transportation. The movement and mechanical behavior of coal have an important impact on the design and failure analysis of scraper conveyor. However, the working environment of the scraper conveyor is complex and harsh, and it is difficult to carry out effective research and experiments. The interaction effect between the underground scraper conveyor and the coal cannot be analyzed in the real test, based on the discrete element method and multi-body dynamics, the rigid-discrete coupling simulation model of the scraper conveyor was constructed, and the simulation model under normal working conditions was verified from the perspective of bulk materials and machinery. The simulation models were set based on different working inclination angles, different strike inclination angles and different traffic conditions, respectively, and the rigid-discrete coupling effect of the scraper conveyor under variable working conditions was studied. The results show that the rigid-discrete coupling model of scraper conveyor based on discrete element method and multi-body dynamics can effectively simulate the transport conditions of scraper conveyor. Under normal working conditions, the coal movement presents a heap-like intermittent distribution, and the coal accumulation on the front side of the scraper is more than that on the rear side of the scraper. With the increase of the working inclination, the highest point of coal accumulation gradually moved towards the rear scraper, the average force on the deck plate gradually increased, and the average force on the rear scraper gradually decreased. With the increase of strike inclination, the highest point gradually shifts to the inclined side, resulting in uneven distribution of coal materials in the line pan, making the stress of coal materials on the inclined side greater than that on the other side, and the stress of the chain fluctuates, and the synchronization of the two chains is poor. With the increase of the transportation volume, the average force of the deck plate and the scraper gradually increases. There is an effective conveying area in the scraper conveyor conveying process. The coal material speed in the effective conveying area is basically the same as the chain speed. The coal material speed near the chute wall is gradually lower. The wear of the deck plate is related to the coal particle - deck plate - scraper (chain) contact and when they form an effective three-body contact, there is a significant upward trend in the force and wear on the deck plate. The research results provide guidance for the subsequent simulation model construction of scraper conveyor wear characteristics and fault analysis under different working conditions, and provide a reference for the analysis of r rigid-discrete coupling effect of scraper conveyor under different working conditions.