Different values for plnsol and pletab displays

[flytfry]

Hello everyone,
I have a problem what i do not understand. When I fill an etable, maybe with the stress s in x-direction then i can plot this etable with pletab-command. There is an option wheter to average the results or not. Normally, the display should be the same as when i use the plnsol,s,x command because of the same data which is stored. But the display is really not the same. Do anybody know the reasons why and give tips? because I use the stress-table for further calculations and map these results onto the surface of my object i need to know the reasons.

Best regards,

Thorsten

 

[MJKing]

Try the plesol command. I think the plnsol command extrapolates from the integration points (gauss points) to the nodes and even averages the results at a given node for all the elements containig that node (if averaging is allowed which I think that is the default). If I remember correctly, my experience is that plnsol and plesol can give slightly different results in a changing stress field.

Hope that helps,

Martin

 

[Drej]

plesol = plot nodal element solution (extrapolate the gauss point values to the nodes)
plnsol = plot nodal nodal solution (extrapolate the gauss point values to the nodes and average these extrapolated values at the nodes - assuming linear materials, if non-linear material then copy the gauss point values to the nodes if under plasticity, creep, etc.., controlled by the ERESX command)

Hence, for general linear analysis, you will see more than one value per node (except corner nodes) for plnsol, and one value per node for plesol (check with prnsol and presol). When you contour these you will see slightly different contours - the difference will largely be dependent upon your mesh density.