Dynamic response mechanism of shield cutter in concrete cutting

To investigate the interaction between shield cutter and concrete, laboratory cutting experiments were carried out, which verified that the essence of cutting is the cyclic process of collision, extrusion, cutting, and peeling between cutter and specimen. The influence of tool rake and clearance angles, tool shape, cutting depth, and specimen strength on the normal cutting force Fn and tangential cutting force Ft of the tool was obtained through the cutting force testing system, and the fluctuation range of Fn, Ft and cutting force Fc under the influence of each factor was obtained through analysis. The research shows that the essence of cutting concrete with cutters was the repeated cycle of collision, cutting, and peeling, and the cutting force was always in a fluctuating state. The rake face played a major role in the rock breaking task, and the required Fn and Ft and their fluctuation decreased with the increase of the rake angle. The cutter with larger rake angle had more obvious pulling and shearing effects on the concrete. The mean value of Fn and Ft had a linear relationship with specimen strength and cutting depth. The larger the specimen strength and cutting depth were, the larger Fn and Ft were, and the smaller the fluctuation in its direction was. The effect of cutting depth on the fluctuation of Fc was greater than that of the specimen strength. The particle size of the debris increased with increasing cutting depth, while the debris at cutter tip was in powder form. Copyright ©2021 Journal of Harbin Institute of Technology.All rights reserved.