Analysis of force and wear mechanism of shield hob under conventional working conditions

Abstract

Abstract In order to study the force and wear of the hob during the excavation of the composite formation, Abaqus simulation is used to simulate the stress state of the hob when breaking the rock and soil. Based on the abrasive wear mechanism, a prediction model of radial wear amount and linear wear rate suitable for a single hob is derived, and verified with actual engineering data. The results show that the normal force plays an important role in the rock breaking of the hob, and the penetration degree and the cutting edge radius are important factors affecting the normal force of the hob. When the penetration degree increases, the normal force and radial wear of the hob will increase, but the increase of radial wear will slow down due to the width of the cutting edge. Working with the “small-large-small” penetration law not only improves the boring efficiency but reduces the loss of the hob. Therefore, the study provided references for the hob wear and optimization research.