Linear vs Quadratic mesh

Im going out on a limp here, but for pretty much everything related to Aster, a quadratic mesh is preferred/required for precise results.
Someone one this forum recently mentioned that quadratic mesh isn't suited for contact simulation, but that is the only case I can think of were linear mesh is preferred over quadratic.

For reference:

Syrthes 3.4.2 will only accept quadratic meshes - (this will change in the upcoming version)

Code_Saturne will read quadratic meshes but convert them to linear meshes when starting the calculation.

Code_Aster will eat anything, but the results will heavily favour quadratic mesh*.

*When viewing e.g. VonMises stress in Salomé or where ever, it is important to postprocess the EQUI_ELGA_SIGM field and not the EQUI_NOUE_SIGM field; this is because the equiv_noue_sigm field is created by interpolating the results from equi_elga_sigm which can lead to imprecise results, especially where stress concentrations are high.

To further muddy the waters, more precise results from Aster are obtained by using quads/hexahedrons over triangles/tetrahedrons.

Kees has some more valuable information at:
www.caelinux.org/wiki/index.php/Contrib:...nt_to_solid_elements


Regards,

Claus<br /><br />Post edited by: Claus, at: 2010/08/29 15:17