| Vibratory mass finishing is a widely used finishing process.The collision,rolling,microfinishing of the blade by the media can comprehensively improve the surface integrity and uniformity of the blade.The surface shape of the blade can be adapted through the collision and impact of the overall the local media group,and can process complex parts such as blades with three-dimensional curved surfaces.In the vibratory mass finishing,the movement mode of the media and the fluidization degree of the different media bed directly affect the processing quality.Aiming at the problems of poor uniformity and consistency in the machining of complex parts with three-dimensional space surface shapes of two-machine blades,this paper uses EDEM to simulate and analyze the motion of the media under the horizontal vibration mass finishing based on the discrete element method.Explore the influence of the flow field characteristics of the media of the horizontal vibration mass finishing on the processing effect of the blade under different parameters,and lay the foundation for the subsequent control of the horizontal vibration mass finishing flow field.The main research contents are as follows:(1)Based on the previous practical experience,the discrete element method and the simulation contact model,parameter setting and data extraction and processing methods of the discrete element software EDEM used in the research are introduced.The average speed of the media in the roller is distributed layer by layer horizontally along the vertical direction through simulation,which establishes the basis for the subsequent simulation method and the processing of the velocity vector diagram.(2)By simulating the flow field of the media under different frequencies and amplitudes of the horizontal vibration mass finishing,the flow mode and flow field characteristics of the media are analyzed with blades in the horizontal vibration mass finishing and through the highspeed photography speed test to prove the effectiveness of the simulation.The results show that under the action of external vibration,the flow field of the media can be divided into three areas:convection area,mixed flow area and steady flow area.As the frequency increases,the average speed of the media reaches its maximum at 18 Hz and then decreases.With the increase of the amplitude,the average speed of the media increases.The changes of parameters that characterize the intensity of convection,such as the bed height ratio,void area,and convection area ratio of the media,are consistent with the change trend of the average velocity with the vibration parameters.Increasing the amplitude is more effective than increasing the frequency to improve the degree of fluidization of convection.(3)The motion state of the media under different frequencies and amplitudes is very different.The addition of the blade hinders the movement of the media in the roller,and the phenomenon of convection is restricted.The upper side of the blade is affected by the combined effects of the sliding and collision of the media,and the lower side of the blade is more affected by the sliding action of the media.The wear amount and its relative standard deviation are used as the evaluation criteria to study the influence of different frequencies and amplitudes on the processing effect of the blade.With the increase of frequency and amplitude,the wear of the media on the blade increases.The relative standard deviation of the blade surface processing wear increases from 12 Hz to 18 Hz,and gradually decreases after 18 Hz.The relative standard deviation of the blade back surface processing wear gradually decreases.This paper uses discrete element software to simulate horizontal vibration finishing to analyze the flow field characteristics and action mechanism of the media under different parameters,and verify the analysis through testing.The flow field of the media analyzes its effect on blade processing and the effect of processing uniformity. |
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