The Residual Stress Detection And Machining Deformation Control Technology Of Thin-walled Aluminum Alloy Fairing Frame

The fairing is a key component of aerospace products,in order to meet the new generation of aerospace products of high speed and high acceleration performance requirements,the design of the fairing is developed from integral type to pair open type.Due to the complex structure,low stiffness and high strength of the open fairing frame,it is difficult to control the product deformation,which becomes the bottleneck problem structure of aerospace products.In this paper,the machining deformation control technology of the open type thin-walled aluminum alloy fairing frame is studied.Through analyzing the structural characteristics and technical characteristics of the thin-walled shell structure products,the type of deformation is combed,and the influencing factors of deformation problems are described.Through the design of different process schemes,trial machining and comparative analysis,a separate machining scheme of "interior cavity milling and external conical surface lathes" was proposed.The deformation factors were changed by changing the blank structure and reducing the machining residual stress introduced during the machining process.The control is performed so that the energy release of the parts is relatively gentle,and the control of the product's radial torsional deformation and axial bending deformation is realized.Combining the preferred process scheme and experimental processing results,the X-ray method was selected as the residual stress detection method through comparison of various detection methods.By setting up the residual stress testing platform,it was determined that the residual stress of the fairing frame was measured before the finishing process.This further validates the influence of stress distribution on the deformation of thin-walled structural products.Tests have shown that the intrinsic cause of the expansion and shrinkage of the large end of the product is caused by the combination of weak structural rigidity and the processing residual stress generated during processing.Based on the residual stress distribution and deformation law,a finite element analysis model was established based on the product structure and machining allowance before the finishing process.The modal analysis determines the range of values for the support and excitation point and the excitation frequency of vibration aging.Through the harmonic response analysis,the values of the excitation frequency and the excitation force are determined,which lays a technical foundation for the development of the spectrum harmonic vibration aging scheme.Taking the metal skeleton of a certain type of fairing as an example,the process of removing the residual stress by vibration aging is added before the finishing process,and the vibration aging test is carried out to achieve the homogenization of the internal residual stress.Based on this,the process scheme is optimized and the correctness of the numerical simulation method is verified.Sex,improve the product processing accuracy,to achieve the control of product processing deformation.In this paper,through the study of the manufacturing scheme of the split-type thin-walled aluminum alloy fairing framework,the deformation control of a certain type of fairing framework is realized,which provides a set of deformation control for such thin-walled easily deformable enclosure structural parts.Learned technical solutions.