A machining position optimization approach to workpiece deformation control for aeronautical monolithic components

Abstract

During high-speed machining of aeronautical monolithic components, the initial residual stresses will cause the workpiece deformations with the removal of material. Therefore, it is crucial to investigate the prediction and control of workpiece deformations for the achievement of a machining process with high efficiency and precision. Above all, the mechanical model is established for the deformation analysis of 7075 aluminum alloy aeronautical monolithic components. Based on the formulated theoretical model, the finite element model is also suggested for the solution of the workpiece deformation. The comparison between the calculated values and the simulated results shows that they are in good agreement with each other. Subsequently, the presented method is adopted to reveal the fact that the different machining positions will cause different workpiece deformations. The deformation experiments are carried out at two machining positions of the workpiece. The measurement results show that whether for the amplitude or the deformation curve, the simulated results are in accordance with the measured data. The relative errors of two groups of data are 9.26% at position 16.5 mm and 19.66% at position 9 mm. Finally, an optimal model is created for the minimum deformation as well as the corresponding step decrease iterative solution method so that the proper machining position is achieved when the step is within the given threshold value. In comparison with the middle position method which is usually adopted by the enterprises, the optimal machining position, obtained by the presented step decrease iterative method, can decrease machining deformations by 99.79%.