Research On Residual Stress Evolution Law And Deformation Of Thin-walled Aluminum Alloy Parts Under Transportation Vibration

Aluminum alloy is widely used in aerospace structural parts due to its high specific strength.However,the large thin-walled long stringer of aluminum alloy is deformed during transportation and the degree of deformation is different.In order to control the transportation deformation,the research on the evolution law of residual stress and the deformation of thin-walled aluminum alloy parts under transportation vibration loading has carried out.The main research contents and achievements are as follows:(1)An electrolytic stripping device was designed.The process is safe and controllable without leakage.The 7050-T7451 aluminum alloy electrolysis experiment was carried out with 200g/L NaCl electrolyte.The optimal process parameters of the current density and the electrolyte flow rate were determined,and the actual electrolytic stripping speed was calibrated.Further,the milling residual stress distribution of the thin-walled samples was measured by X-ray diffraction.(2)Based on the composite stress generated by the milling stress and random vibration stress under transportation,a cyclic loading experiment of thin-walled samples was designed.The relaxation law of residual stress on the surface and depths of the samples after cyclic loading was analyzed.An analytical model of stress relaxation of 7050-T7451 aluminum alloy was established according to the experimental data.(3)Random response analysis of road transportation under numerous working conditions was carried out for a 7050-T7451 aluminum alloy thin-walled long stringer.The distribution regions with high vibration stress of long stringer were obtained.The mathematical model of vibration deformation of the long stringer transportation was derived.The influence of damping ratio and support position on the vibration deformation of thin-walled long stringer was analyzed.The range of damping ratios and the fixed schemes were proposed to avoid transportation deformation.