Java Applet to determine the load carrying capacity and pressure distribution of a tilted (single) rectangular pad
This Java applet uses an iterative solution using the Jacobi procedure and allowing the
user to specify a degree of over or under relaxation (SoR factor). Whereas for many systems of
linear equations, an over relaxation factor of about 1.5 usually gives a reasonably speedy
convergence, it has been found that in this problem over relaxation (greater than 1.0) often
leads to instability and divergence in the solution. It is therefore suggested that under
relaxation - with a factor of 0.9 - is used. This may require 500 or more iterations.
Inputs should be typed in the units specified (SI).
The bearing length is parallel to the direction of 'sliding'.
The slope is dimensionless.
The lubricant viscosity is assumed to be constant.
The number of intervals can be up to 50 in both the length and width directions,
but in practice 10 in each direction seem to give reasonably accurate results. Using a
larger number of intervals will require a greater number of iterations, some thousands.
After all the data has been entered in the text boxes adjacent to the labels, the
yellow "Read Data" button should be clicked, the calculations are then performed and
the progression of the computed load (in N) with the iteration is listed in the right hand text area.
When the iteration is complete, the average pressure (in Pa) acting on the pad is shown in the
text field adjacent to the blue Average Pressure label. The pressure distribution, in MPa,
is shown in the pale blue text area at the bottom of the applet.
If the applet does not load or run, it may be that the settings on your browser
need changing or that you need to download the Java run time environment (JRE).
Note on number of iterations: With 50 intervals in both directions, the 11th significant
figure of the sum of the radial load did not change between 12800 iterations and 20000 iterations.
David J Grieve, 19th November 2009.