302 Z-List Based Modeling of Cutting Geometry and Cutting Forces in 5-Axis Machining of Complex Surfaces

This paper proposes a mechanistic force model in 5-axis roughing and finishing of complex surfaces using the z-list buffer. The z-list buffer has been proved to be robust in modeling the complex surface shape generation given the tool geometry and the tool path. The Boolean subtraction of the solids resulting from sweeping the tool profile along the successive tool path segments generates the substitute geometry of the machined surface. Multiple z-levels can be stored in the z-list buffer, as required for the 5-axis machining. Along the tool path, the chip load is estimated by evaluating the contact area between the tool and the workpiece. The magnitude and direction of the cutting force can be estimated given the chip load and the specific pressure coefficients on the rake face and clearance face of the cutting edge. To determine the specific pressure coefficients, an experimental calibration procedure of the mechanistic force model is used. 5-axis machining of centrifugal compressor blades is conducted to illustrate the approach and assess its performance.