A numerical model for cutting process simulation and prediction of cutting forces in peripheral milling

The machining of metals is sometimes accompanied by a violent relative vibration between the workpiece and the tool, which is called chatter. Chatter is undesirable because of its adverse effects on surface finish, machining accuracy and tool life. It is becoming increasingly problematic due to higher cutting speeds, numerically controlled machine-tools and integrated manufacturing systems. Chatter is the fact that the chip section is not constant, but varies periodically, the law of variation depending upon the diameter, the number of teeth and the helix angle of the cutter, the spindle speed, the feed rate and the depth and width of cut. The periodic variation of the chip section causes pulsations of the cutting force. Also, chatter is caused by the regeneration of waviness of the surface of the workpiece. This regenerative chatter is considered to be one of the most important causes of instability in cutting process. This type of chatter will be considered in this paper. The main aim of this study is to qualify the dynamic behavior of workpiece during the peripheral milling process. A three-dimensional numerical model, allowing the simulation of the peripheral milling process is proposed. This model permits to estimate simultaneously the workpiece displacements and the evolution pf the cutting efforts during time. Finally the influence of damping on the stability of the process is discussed.