Research On Stress Measurements And Distribution Mechanism In Aluminum Thin-Walled Structural Components

High performance aluminum alloy materials are widely used in manufacturing of aerospace structural parts, however, the influence of residual stress on the precision of large structural members has seriously restricted its development. In order to improve the precision of large structure parts, it is necessary to test the stress and deformation of the components. The frame structure is more complex than the plate, so single stress testing methods cannot solve the problem. Therefore, it is of great significance to construct a stress testing system which is suitable to aluminum alloy from the plate to frame member.This paper takes the 7075 aluminum alloy as the research object, and the experiments of milling aluminum thin-walled structural components were carried out, thin wall thickness 2mm, the stress and deformation of materials were studied and the influence of stress on thin-wall frame deformation were analyzed. The research works were done as follows:1. The stress testing technology which were suitable for describing the stress of component, including blind hole method, X-ray diffraction method, deep hole method and layer removing method were studied, especially in the aspect of internal stress test, The model of deep hole method was improved, and the stress distribution in aluminum alloy thick plate was verified by finite element analysis.2. The residual stress testing system of aluminum alloy thin-walled frame was constructed, and the stress distribution of the thin wall frame is described by using this test system.3. Based on the premise of the stress distribution of the components, the structure of the component deformation model was further completed, the relationship between the stress field and the maximum deflection was described, and the mechanism of the stress distribution of the component was well completed.It can play the role of deformation prediction in the milling process of aluminum alloy components, which has important reference value for optimizing the milling process and reducing the deformation.