MACHINING DEFORMATION MODEL AND STRUCTURAL OPTIMIZATION OF AERONAUTICAL MONOLITHIC COMPONENTS BASED ON RELAXATION OF INITIAL RESIDUAL STRESS

In the process of blank forming, the non-homogeneity of mechanical properties of material leads to the residual stress in a aluminum alloy thick plate. During the following cutting process, along with the removal of material, the release of residual stress makes the aeronautical monolithic component deformed, which seriously affects the size stability of an aeronautical monolithic component. Therefore, the quantitative study on the analysis and prediction of deformation caused by the residual stress release during the cutting process is the core link of controlling the processing quality, and it is very important for the realization of machining process with high efficiency and precise. Through equaling the material removal of the aluminum thick plate to the residual stress release, the residual stress of the aeronautical monolithic component is converted to an external force on the basis of static equilibrium conditions. Then considering the residual stress in both the transverse and rolling direction of the plate, the deformation analysis model is established by using bending deformation theory. The comparison between calculated results of a model and the finite element simulated results and the experimental measurement data shows that:both the amplitude and deformation curve and the calculated results are highly consistent with the simulated results; when compared with experimental measurement data there is a deviation in the amplitude due to the measurement error, though the deformation curve of calculated results has a good agreement with them.