Three-dimensional thermo-elastic-plastic finite element analysis with different cutting speeds

Abstract

This study established a coupled thermo-elastic-plastic finite element model for 3-D cutting by combining the large deformation-large strain theory, the updated Lagrangian formulation, and the 3-D heat transfer finite difference equation, in which critical strain energy density or tool geometrical location acted as the chip separation criterion. A tool face equation based on tool geometrical relationship was first derived to be used as the modification criterion for chip nodes. When the tool moved forward, the chip flow line must follow the tool face; this modification criterion was used to constrain the chip flow line. When the chip node sank into the tool, it must be corrected to lie on the tool face with this criterion in order to be physically meaningful. In this paper, mild steel is used as the workpiece material, and P20 as the tool. After the initial contact, the tool moves forward in displacement increment till the formation of steady cutting force. The formation of 3-D chip, workpiece stress, strain and strain rate, residual stress, and the temperature variation for the workpiece and tool under three different cutting speeds were explored. The cutting force obtained in the simulation was compared with an experimental value, which displayed an overall match. Therefore, the results in this paper can act as the basis of qualitative analysis.