Study On Wear Model Based On Friction Heat Effect And Friction Vibration In Running-in Stage

Medical instruments and military industry can not avoid the existence of friction pairs and dry friction,such as 3D printer and machine tool guide rail,lead screw,etc.,so the use of high and high frequency,easy to produce thermal wear by friction,affect the accuracy and service life,bring economic losses.Archard equation is a basic equation mainly used to predict and describe the wear degree between objects.The main disadvantage of this equation is that it ignores the thermal expansion effect caused by object friction and the additional displacement effect caused by friction vibration,and limits the contact positive pressure and relative slip distance to a fixed value to predict and describe the wear condition.This thesis revised the model by combining theoretical analysis,experimental research and numerical simulation.The research contents are as follows:Based on Archard prediction equation,the influence of thermal expansion on friction and wear was ignored.Based on the friction and wear tests of 316 L stainless steel,pure titanium and 5A06 aluminum alloy,the influences of initial normal load and frictional slip velocity on friction heat were explored.The results show that: The larger the relative friction velocity and normal initial contact load,the more obvious the friction thermal expansion,the larger the fluctuation of normal load,and the greater the wear will be with the influence of thermal expansion.In this paper,the Archard wear model is optimized based on frictional thermal expansion,initial normal load and relative velocity.Compared with the traditional Archard model,the modified Archard model can predict the friction and wear situation more accurately.Since the traditional wear prediction model does not consider the influence of friction vibration,based on the friction vibration wear experiment of 316 L stainless steel,this paper explores the root cause of friction vibration and the influence of friction vibration on friction and wear.The results show that: Due to the change of friction coefficient,the energy of the whole friction system transforms among kinetic energy,elastic potential energy and friction work,which leads to the generation of friction vibration.It is also found that the intensity and energy spectrum of vibration increase with the increase of normal force,and the additional displacement attached by vibration also increases.The relative sliding displacements in Archard are modified,and the prediction accuracy of the models based on the friction thermal expansion correction and relative displacement correction is improved to different degrees compared with the traditional wear prediction models.Based on ANSYS finite element software,the new wear model was integrated into ANSYS analysis software by Workbench and APDL,and the traditional wear model and the modified wear model were simulated and analyzed respectively.The results show that: Using traditional wear,wear quality but a linear change and the experiment value is large,the vibration acceleration signal in a cycle gradually stabilized,and the new friction and wear abrasion of model prediction for the surface of the slider is slight deformation happened,in the region of the friction wear morphology due to thermal expansion extrusion effect,in the direction of friction is "M" shape,The maximum wear depth and wear volume increase with time,but their growth rates also increase with time.The wear quality is close to the experimental results.Compared with Archard wear prediction model,the prediction accuracy is improved,and the vibration signal is in an irregular state.And it is similar to the experimental friction vibration signal in spectrum distribution and amplitude distribution.