Research on Tunnel-Boring Machine Main Bearing Fatigue Damage and Vibration Response

Based on the damage evolution equation of bearing steel, a user subroutine was developed to simulate the fatigue damage behavior of the TBM main bearing under the condition of low speed and heavy load. In addition, the damage evolution law of the main bearing in the time domain and the space domain was studied. Then, a nonlinear spring element was introduced to simulate the interaction between the roller raceway, and the vibration response of the TBM after the main bearing damage was studied using the transient dynamic method. The research shows that the damage risk of the raceway is greater than that of the roller, and the damage risk of the main pushing raceway is greater than that of the other two raceways. The damage of the main bearing will not only lead to the increase in the peak vibration response of the TBM but also cause more frequency components of the response. By monitoring the time domain index of vibration signal, the damage degree to the main bearing can be mastered in real time, providing a reference for the maintenance of the main bearing.