Study On The Regulation Behavior Of Groove-Textured Surface In Affecting Friction-induced Vibration And Noise

Friction-induced vibration and noise(FIVN)can be commonly observed in many mechanical applications which contain friction pairs,such as vehicle brake systems,tool cutting systems,bearing systems,mechanical gear systems,lead screw drives,rail-wheel systems and powertrains.FIVN has a negative effect on the precision and reliability of many mechanical systems,and the emitted noise is considered as a serious pollution for people's daily lives.Considering that FIVN is a result of unstable vibration from frictional interface,a large amount of work has been conducted to study the effect of surface topography on FIVN.However,the complicated and uncertain interface conditions will cause difficulties in predicting and evaluating noise performance,thus no consensus has been formed to explain the relationship between micro-surface topography and FIVN.Nowadays,textured surfaces have received much attention from tribologists because of their good geometric repeatability and tribological properties.However,the knowledge of the relationship between textured surfaces and FIVN are still limited and somehow mysterious.This surface treatment technology can help manufacture regular and repeatable surface,which is beneficial for getting a better understanding of FIVN properties and generation mechanism.In addition,textured surface can be used to regulate the contact behaviors directly and indirectly.Therefore,investigating the effect of textured surfaces on FIVN is extremely worthwhile,which in consequence might help further investigate the generation mechanism of FIVN,and is of considerable importance for the optimal design of surface topography and structure to reduce the friction noise.In this work,the effect of groove-textured surface on FIVN is studied,the main work and conclusions are summarized as below:(1)The effect of groove-textured surface on the friction-induced vibration and noise is studied by using both the experimental test and finite element analysis.The mechanism of interfacial friction-induced vibration and noise controlled by groove-textured surface directly is systematically analyzed,and the relationship among the contact state,friction and wear and friction-induced vibration and noise is established.Surface modifications of metal discs with different grooves configurations are investigated for acquiring enhanced performance against FIVN.Results show that the disc surface with grooved modifications can help reduce the squeal instability of friction system.The grooves are found to be able to play a storage cavity role in trapping wear debris and improve the wear features of the disc surface.The disc surface with a specific groove configuration(T-45 surface whose grooves form a 45°-angle with the local linear relative velocity)can significantly reduce squeal.Finite element analysis results show that the grooved disc surface has a capability in modifying the dynamic behavior through periodic mode coupling and decoupling,and thus reduce the tendency of squeal noise.Additionally,the grooves on the disc surface is able to affect the contact pressure distribution of the pad surface during the friction process,and redistribute the concentrated interface pressure and consequently suppress squeal generation.(2)A special kind of flat surfaces which possess space-varying contact states is designed and manufactured,to validate the role of the grooves in improving FIVN via trapping wear debris.Different materials are filled into grooves of the grooved textured surfaces,which accordingly establishes a kind of special surface with time-varying contact characteristic.Results show that adding aluminum material into the grooves will promote the generation of FIVN,and increase unstable vibration level of the friction system.In contrast,adding steel material into the grooves can demote the generation of FIVN from the contact surfaces and reduce the unstable vibration level of the friction system.Severer wear states and wear debris accumulation at interface can promote the generation of FIVN,and increase the intensity of FIVN,which accordingly validate that the capability of groove-textured surfaces in trapping wear debris is beneficial for reduction of FIVN.(3)The effects of the groove-textured surface on the frictional and wear and FIVN of the interface under different contact modes are clarified,and the mechanism of the interface grooves on the FIVN behavior under different contact modes is revealed.A study on how the grooves affect tribological properties and vibration and squeal noise behavior is performed,by using both a ball-on-disc and pad-on-disc configurations.Results show that regardless of the contact configurations,grooves on the disc surface can significant affect the tribological behavior and squeal noise performance.The grooves play different roles in affecting the FIVN for the ball-on-disc and pad-on-disc configurations.For the ball-on-disc configuration,the collision behavior between the ball and the edge of the groove helps suppress the friction squeal.For the pad-on-disc system,no visible collision behavior can be found between the pad and the edge of groove,and the variation and redistribution of contact pressure during pad's sliding across the grooves on the disc surface is thought to be the major reason for the reduction of squeal instability of friction system.(4)The effect of grooved damping component(SBR)on the friction-induced vibration behavior is studied,and the behavior of SBR indirectly controlling the friction-induced vibration is systematically discussed.The rubber damping components(SBR)are introduced into the friction system,it is found that the rubber damping component can adjust the contact surface during the process,this adjust behavior help the contact pairs maintain a good contact condition with each other,and alleviate the effect of surface run-out.Adding grooves on the surface of SBR can further reduce friction-induced vibration level,suppress the generation of vibration main frequency and alleviate the effect of disc surface run-out.Moreover,it is verified that the grooves in the middle region of the surface can reduce the vibration amplitude,but cannot suppress the vibration frequency.While the grooves in both of leading and trailing regions of the surface can eliminate higher vibration frequency to some extent,but neither can help reduce the vibration amplitude.(5)Taking Mn-Cu damping alloy as the research object,the indirect control behavior of the Mn-Cu damping alloy to the friction and wear and FIVN characteristics is studied systematically,and the internal relations among the damping alloy,FIVN and the friction and wear are discussed.The Mn-Cu damping alloy is introduced into the friction system,and the ability of grooved damping alloy component on the FIVN and wear behavior is studied using both the experimental and numerical analysis methods.It is found that the Mn-Cu damping alloy can help reduce the FIVN of friction system.Moreover,the grooved damping component has a better performance in suppressing the generation of FIVN.Numerical analysis results show that the deformation of damping can reduce the pressure concentration on the pad surface,which is beneficial for the pad surface to exhibit a more uniform pressure distribution and reduce the FIVN level of friction system.Because the deformation of grooved damping is larger than that of the smooth damping,thus friction system with grooved Mn-Cu damping alloy component has a better potential in reducing the FIVN.The improvement of contact pressure distribution caused by adding damping component can improve the wear status of interface.The improvement of the interface wear status can also suppress the deterioration of FIVN.Meanwhile,the reduction of FIVN behavior can also alleviate the wear level of interface.According to this analysis,it can be explained why adding the grooved damping component in system has the best ability in reducing the FIVN.