Feedrate optimization of complex surface milling based on predictive model of cutting force

Abstract

In terms of the low machining efficiency and bad surface quality using constant feedrate in complex surface milling, a feedrate optimization method is proposed based on cutting force model. Firstly, by the analysis and calculation of the tool path, the geometry of complex surface and tool, tool-workpiece engagement zone and uncut chip thickness, a cutting force model is derived in multi-axis maching of complex surface and the mapping relation is obtained between feedrate and cutting force. Then the objective function about the absolute value of difference between the reference cutting force and the maximum one calculated in each tool position is put forward. Then the method adopts Newton-Raphson iteration algorithm to alter the feedrate in the original tool path file, thus ensures the constant cutting forces and enhance steadiness of machining process. The experiment is carried out about model propeller, the results show that the proposed optimization method ensures the machining time of the blade reduced by more than 25%, the surface residual stresses and micro-hardness machining accuracy to be increased, which has a clear effect on increasing the machining efficiency and improving the machining surface quality of the blade. This thus validates the effectiveness of the proposed optimization method.