Generation And Propagation Law Of Stress Wave In Milling Aluminum Alloy 2219

The rapid development of manufacturing technology has effectively promoted the extensive application of large-scale aluminum alloy sheet parts for overall cutting in the aerospace industry.However,as the cutting speed continues to increase,the strain rate effect and the wave effect of the processing region gradually increase,which seriously affects the chip forming process and the surface quality of the workpiece during material removal.When the stress caused by the stress wave is greater than the yield strength of the material,the material will be plastically deformed,which will affect the residual stress of the milled surface.Therefore,the research on the generation and propagation of stress waves in aluminum alloy sheets during milling has important implications for improving the surface quality and residual stress distribution of the workpiece.Taking the process of milling aluminum alloy 2219 as an example,the plane longitudinal and plane shear wave equations were established.Combined with the stress-displacement relationships,initial conditions and boundary conditions,the integral-transform method was used to solve the wave equations,and the mathematical models of longitudinal and shear wave propagation were obtained.Two-dimensional cutting simulation was carried out using the finite element simulation software ABAQUS.The propagation and evolution laws of the longitudinal and shear waves are consistent with the numerical results.The influence of cutting parameters on stress wave propagation was analyzed,and the stress wave attenuation function was fitted.The results show that stress waves are directly related to the external load,and the stress waves are attenuated in an approximate exponential form.A longitudinal wave fluctuation signal measurement scheme for vertical milling surface orientation was designed,and the influence of milling force on the acceleration signal was analyzed.Through the single factor milling experiments,the influence of milling parameters on the milling force peak and acceleration peak was analyzed.The theoretical conclusion that the stress wave is directly related to the load was verified.In addition,the influence of milling parameters on residual stress was analyzed.The results show that the residual stress is more obvious in the direction of larger milling force.The milling stress wave propagation and dynamic response law in the surface of the workpiece were studied.Through the 3D simulation,the variation of stress in the surface of the workpiece with time was studied.The dynamic strain of the workpiece was measured by milling experiments,and the experimental results were consistent with the simulation results.It lays the foundation for stress wave measurement in the plane.By adjusting the spindle speed,the influence of the loading frequency on the dynamic response of the workpiece was analyzed.It is found that the frequency of workpiece strain is constant at different milling frequencies.A dynamic strain measurement method for the feed direction and the vertical feed direction in the surface of the workpiece was designed.The dynamic positive strain and the dynamic shear strain were decomposed.The influence of milling force on dynamic strain was analyzed.The strain disturbance caused by the longitudinal wave and the shear wave propagation in the surface of the workpiece was measured.The propagation and attenuation laws of longitudinal and shear waves on the surface of the workpiece were analyzed.The results show that the attenuation speed of longitudinal wave is faster than that of shear wave.The unloading fluctuation increases first and then decreases as the distance between the milling cutter and the measuring point decreases.