Elastohydrodynamic Analysis of Rolling Line Contact Using Boundary Element Method
This study aims at incorporating the use of the boundary element method (BEM) as an efficient and fast numerical method for the solution of the problem of the elastohydrodynamic (EHL) of hard rolling line contact. EHL of hard rolling is the dominant mode of lubrication in many critical, highly st...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English English |
| Published: |
2001
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/7979/1/ITMA_2001_7_.pdf |
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| Summary: | This study aims at incorporating the use of the boundary element method
(BEM) as an efficient and fast numerical method for the solution of the problem of
the elastohydrodynamic (EHL) of hard rolling line contact. EHL of hard rolling is
the dominant mode of lubrication in many critical, highly stressed machine elements
such as gears, cams and followers, and bearings. The study of the stress
concentration and deformation is important to predict the performance and the life
expectancy against failures. These failures are manifested in wear, fatigue and
scuffing. This fundamental study is based on isothermal, steady state, and smooth
line contact EHL. The rolling of two cylindrical rollers was approximated by a
roller and a plane.
The hard rolling EHL relates to counter-formal contact elements made of
high elastic modulus materials such as metals. The problem is to seek a solution,
which reconciles the hydrodynamic equation represented by the Reynolds equation,
and the elasticity equation while at the same time allowing for the variation of the
lubricant properties with pressure. The resultant regime is highly non-linear. A hybrid solution is util ised to solve the elasticity problem using the BEM,
and to solve the Reynolds equation for the pressure us ing the finite difference
method (FDM) in a ful ly coupled solution. The BEM fundamental ly consists of the
transformation of the partial differential equations, which describe the behaviour of
the variables ins ide and on the boundary of the domain into integral equation
relating to the boundary values, and the numerical solution of these equations. The
boundary integral equation is formulated for the elasticity and solved using the
BEM. The hydrodynam ic equation is solved using FDM. The coupled solution i s
solved using Newton-Raphson iterative technique. The converged solut ion gives the
pressure distibution and the l ubricant film thickness.
The overa l l result of executi ng the hybrid BEM-FDM program gives a ful l
agreement when compared to the program using FDM while resu lting i n reduction
in the C PU time. The results also agree with other published numerical works. These
veri fy the use of the developed method. To fu l ly uti l ize the advancement of the
developed program, an extension of the models needs to include a non-Newtonian
behaviour of l ubricant and the thermal effects. |
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