problem topologico hm

[Eversor]

hello to all, first of all it is fantastic to see that there is a nice forum for all Italian designers.
I am a student at the last year of engineering, for the thesis I am processing a helicopter seat model through catia, hypermesh and ls-dyna.
Having available the solid dyna model I exported a step component to make the mesh through shell plane elements. with hypermesh 9 I extracted the average surface, but now when I use the automesh command, the result is quite painful... There are numerous unwanted holes in the mesh, as if the surfaces were not properly combined.
I think it has to do with the edge, that instead of being flat is curved, but I don't know how to straighten it!
It's almost a week I try, but I have more ideas.

 

[MacGG]

hi eversor,

I don't understand what you're doing, that is, dyna, you exported the model in step and you imported it in hm right?

Have you tried, before starting the average surface, if this imported solid as step is really seen as a single solid? for example by automesh on the solid? This could make you understand what the problems are.

Hi.

♪

 

[Eversor]

Oh, my God, I'm sorry, I messed up with the names, the model I did in ca. 5.18, dyna is the solver...

you are a unique solid, so much so that the solid elements automesh works wonder.
the problem is that when I use the midsurface command I get a folded surface, which does not respect the symmetry plane.

in teroia it would be enough to move on the symmetry plane some points of the midsurface. When I do this, however, the boundary lines of the surfaces do not remain straight, but they curve at the node... or at least I do.
in red I highlighted the surface that I translated on the symmetry plane and the sides as they were before the translation.

looking at the surface the sides seem straight, but when I do the automesh it seems that only the last knot has moved. . .