The 3D Reconstruction And FEA Of Interfaces For Contacting Mechanical Seal

As the environment issues getting serious, greater demands are being placed on the security and stability of mechanical seal. Because of the existence of roughness, the fluid will leakage from one side of the interface for seal to the other side under the working condition pressure,even cause the failure of the seal. In order to seek the principle of seal leakage, this paper conducts the research on the rings of seal. By the reconstruction model, the transformation of the interface porosity under varied pressure could be discussed. The main works of this paper are summarized as follow:(1)The program that use 2D sectional images to reconstruct the surface topography for seal was researched. A technique to choose the optimum segmentation threshold was proposed during the introduction of common image processing. A new characterization based on fractal theory and porosity to describe the sealing topography was introduced, a algrithm based on voxel to calculate the fractal dimension and the porosity was designed. When the box can't cover the 3D datas accurately, the error will be lager as the size of box increasing. The influence that caused by sampling number of layers on the calculating results was discussed. The caculating accuracy will be elevated remarkably when the sampling number is small, but when the number reach some value this tend will not increase considerably. A software program was also developed based on MATLAB GUI to achieve the manipulation above-mentioned.(2)Combining the technique of curve construction in Imageware and 3D modeling in PROE,the substantiation of 3D datas was fulfilled. The method of point cloud processing and the common surface topography construction was provided. With regard to Gaussian surface, the construction surface will be isotropy when the autocorrelation length are equal. Otherwise, the surface will be anisotropy. To the fractal surface, the dimension reflects the complexity of surface profile while the scale factor shows the amplitude of the rough surface.(3)The FEA research was conducted through ANSYS Workbench on the materialized model.The load that the stationary ring bears will tend to be nonlinear increasing with the displacement getting larger. At the initial stage, some area on the surface has already support high load, but the load increasement slows down as the displacement augments. When most asperities comes into plastic deformation, the load increasement accelerates again. During this process, the porosity of topography decreases all the time.