Finite Element Simulation of Chip Formation and Comparison with Machining Experiment

Abstract

This paper presents a finite element model of orthogonal machining by using a 2-node link element to simulate chip separation. The chip and workpiece are connected by these link elements along a predefined separation line. The chip separation will be initiated when the distance between the leading node and the tool edge is equal to or smaller than a given value. Consequently, as the tool advances, these link elements will be separated one by one resulting in the formation of the chip and the machined surface. Work material behavior is described by true stress-strain curves for a 0–3 strain range. The chip-tool interaction is modeled as sliding/sticking. In the sliding region a constant coefficient of friction is employed and in the sticking region the shear strength of the workpiece is used. Comparison between simulated and experimental results for machining 70/30 brass and OFHC copper shows a maximum difference of 20 percent, which is acceptable considering the assumptions and the approximations made in the analysis.