Meitan kexue jishu (May 2023)
Numerical simulation of cooperative breaking rock by multi-cutter and research on the layout law of disc cutter on cutterhead
Abstract
The cutterhead was one of the key parts of the Tunneling Boring Machine to achieve tunnel mining. Cutterhead’s continuous breaking rock was the rock destruction process under the cutter group. The cutter of cutterhead was used as a direct tool for rock breaking, and the arrangement of the cutter would directly affect the breaking performance such as the force of cutter and energy consumption. This paper mainly explores the influence of cutter installation parameters on the rock breaking force and specific energy in the multi-cutter collaborative rock breaking mode. Firstly, the characteristics of rock breaking during the cutter excavation and the way of multi-cutter collaborative effects created by the adjacent cutter during the rotation are analyzed. Using the motion characteristics of multi-cutter around the center of the cutterhead rotation and slow penetrating into the rock on the cutterhead, a rock constitutive model including the cutter’s displacement loading method and the form suitable for simulating the damage of rock element in the excavation was established, a finite element model of three cutters rotary rock breaking for techniques such as rock failure separation criteria was introduced. This paper simulates the rock breaking process of multiple cutters spiral intrusion rocks. Then, the single-factor influence of three main cutterhead arrangement parameters, cutter spacing, cutter installation polar angle difference and cutting sequence, on the rock breaking performance indicators such as rock breaking force of cutter and specific energy is analyzed by finite element simulation calculation. Finally, an orthogonal experiment is designed to analyze the influence of the above parameters on the total force of rock breaking under the interaction of multiple factors. The results show that the cutter spacing and installation polar angle difference have the most significant influence on the rock breaking performance of the cutter under the cooperative breaking rock conditions. The cutter spacing affects the penetration of lateral cracks between adjacent cutting paths. With the increase of the tool spacing, the lateral crack penetration between adjacent cutting paths is gradually difficult, and the weaker the effect of adjacent cutter radial collaborative rock breaking. The installation polar angle difference affects the penetration of lateral cracks and inclined free surface. With the increase of the installation polar angle difference, the lateral crack connected to the inclined free surface becomes longer, and the cooperative rock breaking effect of by adjacent cutter in the circumferential direction of the cutterhead has been enhanced.This work analyzes the relationship between the arrangement of the cutter and the rock breaking performance of the cutter in the multi-cutter collaborative breaking rock condition, which provides a reference for the reasonable layout of the cutterhead cutter.
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