Technical Research On Drawing And Forming Process Of Aviation Structures

High-strength aluminum alloys are increasingly used in aerospace,automotive and other fields due to their unique lightweight and high strength characteristics,and are increasingly becoming the material of choice for lightweight direction.At present,for aluminum aerospace aluminum profiles,the development trend of large-scale and integrated,thin-walled and lightweight,precise cross-sectional size and shape tolerance,uniformity and high-quality of structural properties,etc.The dimensional accuracy of the parts is higher.In order to achieve high-quality bending and forming quality,the highprecision bending and forming process is bound to become the key technology for the processing of aluminum structural parts.The rebound is the main factor affecting the quality of the stretch forming,which largely determines the filming degree of the structural members of the profile.This paper takes the A7075-T6 profile structural part as the research object,the ABAQUS is used to establish the finite element model of stretch-bending process for ?-Section aluminum alloy profiles,the stretch-bending process is numerically simulated,and the influence of the variation of pre-pulling amount,tensile pulling amount,bending radius and friction coefficient on the curvature rebound is analyzed.The results show that: pre-pulling amount,tensile pulling amount,bending radius and friction coefficient will all affect the rebound amount,and the influence of tensile pulling amount on rebound is more obvious;When the pre-pulling amount is 1%,the tensile pulling amount is 2%,the friction coefficient is 0.08,and the bending radius is 200 mm,the forming quality is obviously better.When the temperature of the alloy material increases,the plastic forming ability of the structural member is enhanced.To study the influence of temperature conditions on the rebound,a thermal coupling model is established to analyze the effects of different initial temperatures and mold temperatures on the rebound.In the range of 50-20 °C,the rebound amount decreases with the increase of the initial temperature of the structural member;in the range of 25-100 °C,the rebound amount decreases with the increase of the mold temperature,but the effect is not obvious.The numerical simulation results of the bending and forming were verified by experimental methods.The research provides technical support for improving the dimensional accuracy of such aluminum alloy profile parts and the research results have certain engineering application value.