Duffers guide to Hypermesh/Optistruct
I rarely use this program, but it does one thing (optimisation of FE models) so nicely that it is a handy tool even so. I found the HM tutorials rather dull since none of them really started from scratch and ended with a solution.
So as a memory jogger for me, and maybe a useful intro for you, here goes:
0) /tool /delete is the most often used subpanel
1) //files /import geom iges double click in box and find your iges file, set cleanup tolerance manually <import> <return>
2) /global select optistruct template
3) VERY IMPORTANT /tools/rotate the surfaces into the correct axes. select the surfaces by selecting and clicking surfs and hitting all. select the base point for the rotation by clicking base and then edit. Select the axis of rotation by clicking the idiotic N1 N2 N3 dropdown menu and selecting an axis.
4) and /tool/scale it +25.4 is in->mm
5) //collector create/edit a material collector using card image mat1 E nu rho 2.1e4 .3 7.843e-6 called steel
and a comp collector psolid
6) IMPORTANT save the model as an hm file and retrieve it. This will show the free edges. Use geom cleanup to toggle free edges. god knows how this is supposed to work. random switching using lmb and rmb seems to work. in vis opts you can switch shared edge display off, which helps. read help.
7)Save it again, the meshing can be a bit annoying.
8) 2d automesh, /trias only/, shift F3 to see if any edges have opened up. Equivalence merges coincident nodes. Use it
9)delete all surfaces (not sure if this is necessary)
10) 3d automesh
11) delete all ctria3
12)/BCs add some constraints.
13) add some loads
14) solve it
15) Optimisation - do the a arm tutorial.
Cheers
Greg Locock
SIG
lease see FAQ731-376 for tips on how to make the best use of Eng-Tips.
