Investigation On The Tribological Characteristics Of Porous Viscoelastic Body On Imbibition Interface

The porous viscoelastic body is widely used in the field of mechanical engineering based on its unique material characteristics.And the interface friction contact behavior of porous viscoelastic body will also determine the actual material properties of it.The external liquid will enter the internal system of porous viscoelastic body through imbibition,squeeze and other behaviors.Therefore,the friction behavior mechanism of porous viscoelastic body will be comprehensively affected by many factors,such as pore shape and liquid state in pores,etc.However,the influencing mechanism of them has not been accurately described based on the previous research.In this paper,the imbibition behavior mechanism and the interface friction characteristics of porous viscoelastic body are investigated in combination.The real contact friction state,multiscale stick-slip behavior and friction mechanism on imbibition interface of fabric,a typical strip porous viscoelastic,are mainly studied.Moreover,the imbibition behavior and interface friction characteristics of PDMS(polydimethylsiloxane)porous silicone rubber,a typical irregular porous viscoelastic,are further studied.It can further expand the interfacial tribological theory of porous viscoelastic body considering the liquid imbibition behavior.And it can also provide the research basis for the potential engineering application of sealing of friction pairs,etc.It has significant theoretical value and practical engineering significance.Firstly,the in-situ observation experimental device for friction behavior and real contact state is built.The real contact area of fabric is captured based on image processing method,and the quantitative relation between the real contact area and the dynamic evolution of interface friction characteristics under different loads and velocities is established based on Howell theory equation.On this basis,combined with the structure characteristics of fabric viscoelastic body,the multiscale stick-slip behavior and the stability of friction behavior on fabric contact interface,including macroscopic,mesoscopic and microscopic scale,are studied.Furthermore,the internal relationship between the stick-slip behavior of each scale interface is further established.Secondly,based on the analysis of the interface friction characteristics of the fabric,the influence of the imbibition behavior is further considered and the observation of the liquid imbibition behavior in the fabric is realized.The difference and relationship of the liquid imbibition behavior of fiber,yarn and fabric under different structural scales are quantitatively analyzed based on the volume expansion rate and other parameters.The influence of the dynamic change of liquid content on the friction characteristics of the imbibition interface under the condition of constant liquid volume and liquid evaporation,a reverse process,is also studied.Thirdly,based on the analysis method of fabric friction and imbibition behavior,combined with the quantitative parameters of imbibition process and Washburn-Darcy theory equation,the imbibition behavior of porous silicone rubber with different nominal elastic modulus under different liquid properties is compared and analyzed.And the changes of surface morphology and quantitative parameters of morphology before and after imbibition process are investigated.In addition,the influence of rubber film thickness regulation on interfacial wettability,which is closely related to liquid imbibition behavior,is analyzed.Finally,based on the rubber surface contact theory,the influencing factors of velocity,load,liquid characteristics,nominal elastic modulus of rubber and imbibition duration time on PDMS porous silicone rubber imbibition interface is introduced.Furthermore,based on the stability analysis of friction behavior,the analysis and comparison of friction behavior mechanisms of different PDMS porous silicone rubber imbibition interface are realized.Moreover,the influence degree and internal influence mechanism of various factors on the friction characteristics on imbibition interface are further analyzed.The correlation mechanism between the imbibition behavior and the interfacial friction characteristics of porous silicone rubber is further established.