Incremental Characterization Of Surface Stress Of Thin-walled Members And Its Application In Deformation Description

Due to the high material removal rate,thin wall and large size of the thin-walled aluminum alloy members,they are affected by the initial internal stress and processing stress of the blank during the milling process.The shape of the formed part will be deformed after forming,which will affect the assembly.Use is one of the most difficult problems in the field of aerospace manufacturing.Therefore,the study of the surface stress test method of aluminum alloy thin-walled structural members and the influence of surface stress on the deformation of thin-walled parts are of great significance for the engineering application of thin-walled members.In this paper,7075-T651 is taken as the research object,and the surface stress characteristics after milling and shot peening are analyzed.The equivalent model of surface stress is proposed.The deformation of aluminum alloy thin-walled members is described by mathematical analysis method.Finally,the experiment is carried out.Verification,the specific research work is as follows:1.The use of improved layer-by-layer drilling method to characterize the surface stress of thin-walled parts.Based on the anisotropic characteristics of the material,the elastic modulus is used as the correction factor to measure the anisotropy of the material based on the original mechanical model.The calculation model has improved and the finite element method is used to obtain the specific calibration coefficient.The method is not affected by the change of the microstructure of the material and can refine the surface stress distribution of the material.2.Analyzing the stress field of thin-walled components measured by experiments,according to the surface-internal stress distribution characteristics,a simplified model of equivalent surface stress is proposed,and the milling process of thin-walled components is simulated by finite element simulation software MSC Marc.which verifies the feasibility of the simplified model.3.The stress equivalent simplified model is used to calculate and analyze the deformation of thin-walled members.The theoretical results are in good agreement with the measured ones.At the same time,the error sources affecting the model calculation are analyzed,and the corresponding error control strategies are put forward.