| The friction process between the rotating band and tube material has important significance to the study of gun life and shooting accuracy and dynamic friction coefficient is an important parameter to describe the process of friction.Achieving the dynamic friction coefficient by measurement is the most pressing way,therefore the research on the dynamic friction coefficient between the rotating band and tube material was developed.According to the test requirements of the dynamic friction coefficient between the rotating band and tube material,a test method for the dynamic friction coefficient has been put forward.The test principle of dynamic friction coefficient was given and during the high speed friction process between the rotating band and tube material,the characteristics of friction and normal pressure was studied by simulation.Other factors that affect dynamic friction coefficient were also discussed,and the design requirements of test device for the dynamic friction coefficient between the rotating band and tube material were given.A test device for the dynamic friction coefficient between the rotating band and tube material was designed,and an experimental test system was set up.The test device for dynamic friction coefficient between the rotating belt and tube material was composed of ballistic gun,sliding assembly,friction sensors,pressure sensors with a friction surface and corresponding acquisition devices.The sliding component was driven to the required speed by ballistic gun,the friction belt on the sliding component was squeezed into the pressure sensor with a friction surface and the friction force sensor was stretched.The pressure and friction signals were output through pressure and friction sensors,and the high speed friction and the measurement for dynamic friction coefficient between the rotating band and tube material were achieved.Based on the principles of elastic cylinder and thick wall cylinder respectively,the dynamic strain gauge friction force and pressure sensor were designed.The material of sensors were selected and the structures were optimized.The frequency response ranges of sensors were improved.The static and dynamic characteristics of the sensors were simulated and analyzed by ANSYS software.The response frequencies of the dynamic strain gauge friction sensor and pressure sensor were 3399Hz and 67KHz respectively as the analysis results showed.Based on the test device for dynamic friction coefficient between the rotating band and tube material,the friction process at the initial velocity of 550m/s was simulated and analyzed,and the phenomenon of high speed friction was explained.The response curves of the dynamic strain gauge friction force and pressure sensor were obtained and analyzed.The friction coefficient was calculated according to the curves,and the property of the test device for the dynamic friction coefficient between the rotating band and tube material was verified.The friction coefficient at a friction velocity of about 500m/s was tested and analyzed by the test device.In terms of the severe high speed friction environment between the rotating belt and tube material and the seriously disturbed response signals of the sensor,the measured friction strain and pressure strain signals were denoised based on the wavelet denoising method.As the dynamic friction coefficient measurements result showed,the value of the dynamic friction coefficient was about 0.03 at a friction velocity of about 500m/s. |
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