Abstract
A numerical method is presented for evaluating the elastic-plastic contact of real rough surface contacts during running-in. For the surface contact, an elastic-plastic model based on the variational method is applied to analyze the pressure distribution and contact area of worn surfaces during running-in. In conjunction with the classical statistic model of Greenwood and Williamson, the numerical result showed that the plasticity index psi was decreased to one in the elastic range as running-in proceeded. In comparison with the Hertzian solution, the influence of the asperities is very significant on the pressure distribution. thereafter causing a higher peak value of contact pressure. For the subsurface, the interior stress from the von Mises criterion was calculated to evaluate the subsurface stress field subject to both normal and tangential forces. In the calculation of the interior stress, the total stress is decomposed into a fluctuating component and a smooth component. The fluctuating part is solved by using FFT from the concept of the convolution theorem while the smooth parr is obtained directly by analytical solution. Calculations of contact area and subsurface stress on experimentally produced surfaces whose topography has been determined using an atomic force microscope and friction coefficient from sliding have been carried out. The results show ed that asperities and friction coefficient gave rise to stress increase in the near-surface stress field and produced a high stress zone towards the surface . As a result, transverse asperity cracking was produced. calculations and supporting experimental evidence clearly confirmed that the reduction of peak pressure during running-in decreased the plastic deformation of contact.
Original language | English |
---|---|
Pages (from-to) | 428-436 |
Number of pages | 9 |
Journal | Tribology Transactions |
Volume | 44 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2001 |
Keywords
- elastic-plastic contact
- surface roughness
- interior stress
- running-in
- NUMERICAL-MODEL
- WEAR
- TOPOGRAPHY
- FRICTION
- STRESSES
- BEHAVIOR