Experimental Study On The Characterisation And Testing Of The Joint Surface Of Interference Assemblies

The components of mechanical devices are usually assembled according to certain standards,and the assembly process produces mutual contact surfaces,called bonding surfaces.The existence of the bonding surface disrupts the continuity of the assembly,resulting in contact stiffness and thermal resistance,which directly affects the mechanical and heat transfer properties of the overall structure,therefore the analysis of contact thermal resistance of rough contact surfaces etc.is of great significance to the design of mechanical structures.In this paper,the analysis of contact thermal resistance of the joint surface of interference assembly is the object of study,and the influence of thermal deformation and contact load on the amount of interference is also taken into account to correct the amount of interference.The details are as follows.(1)Measurement of rough surface topography and analysis of characteristic parameters.The surface profile characteristics and composition of the rough surface are described in detail,the surface profile parameters of different roughness samples are measured using a surface profiler;the rough surface data are fitted by the moving least squares(MLS)method,and the rough surface characteristics are obtained based on the fitted curves,and the contact thermal resistance of the interference assembly surface is calculated.(2)Modeling the "thermal-structural" coupling of the joint surface of the interference assembly.The mechanical model and the heat transfer model of the joint surface of the interference assembly are established respectively to obtain the relationship between the amount of interference and the contact pressure,the amount of thermal expansion and the temperature distribution.Combined with the elastic,plastic and elasto-plastic deformation process of a single micro-convex peak to modify the overfill amount,to establish the thermal-structural coupling model of the annular bonding surface.(3)Finite element simulation modelling analysis of the overfill assembly bond surface.Use Comsol Multiphysics 5.6 finite element analysis software to conduct a comparative study of the contact area,contact thermal resistance,contact pressure and other parameters at the bond surface,and compare the model with the calculation results in(3)to verify the validity of the model.(4)Experiment of measuring the temperature field distribution on the surface of the bond surface of interference assembly.In this paper,experiments are designed and conducted to measure the surface temperature distribution of the annular bond surface.The experimental results found that: the temperature increases with the increase in the amount of interference,basically in a primary function relationship,but the rate of increase is slightly different.The experimental data was compared with the simulation results and the error was within acceptable limits,verifying the validity of the model.