Uncertainty analysis and time-dependent reliability estimation for the main shaft device of a mine hoist

Abstract

The main shaft device (MSD) is a key component of the mine hoisting system. During lifting, vibration of the system will cause dynamic tension of wire rope at both ends, resulting in the complex stress state at the critical location of the MSD and thus considerably decreasing its service life. This study is aimed at investigating time-dependent reliability of the MSD based on fatigue damage accumulation. Firstly, the actual service-loading history of wire rope during lifting was simulated. Then, the residual strength degradation models of the MSD following different shifts were established based on Palmgren-Miner hypothesis. Furthermore, the performance function of time-dependent reliability considering residual strength degradation was established. Finally, time-dependent reliability of the MSD was evaluated by adopting moment-based saddlepoint approximation. The results show that when the MSD follows a heavy shift, the corresponding reliability drops rapidly with the passage of service time. In addition, a reliable shift of the MSD after gridding was made. According to this shift, the remaining reliable service life of the MSD for multi-shift can be predicted.