Mailing list archives : pcb-rnd

ID:4245
From:N <ni...@gmail.com>
Date:Sun, 5 Jul 2020 23:30:19 +0200
Subject:Re: [pcb-rnd] bugreport: mesh
in-reply-to:4244 from Evan Foss <ev...@gmail.com>
replies: 4249 from ge...@igor2.repo.hu
> On Sun, Jul 5, 2020 at 1:25 AM <gedau@igor2.repo.hu> wrote:
> >
> >
> >
> > On Sun, 5 Jul 2020, Evan Foss wrote:
> >
> > >Ok. If since it's a missing feature I suggest another one. At the very
> > >least there should be a warning in the log window that lets the user
> >
> > I disagree. We don't warn for copper text, and our arc handling is
> > not very clever either. These are called known limitations.
> 
> Well once more users show up we will see which opinion is right.
> 
> I had assumed the meshers algorithm started by placing lines on the
> ports and then worked out how to handle the copper edges.
 
It is common with adaptive refinement, solution is used to estimate accuracy or put an upper bound on error which is used to decide then and there mesh should be refined. Unless original geometry is kept adaptive refinement will cut corners, may be a problem if mesh is course while refined at round end, remember I had to do some kind of workaround in solver for this once.
 
Then it come to CAD step, .step or .stp is common and think it is common component manufacturers make 3D models available in this format. Then I investigated the CAD software pcb-rnd export to I do not however think they import this format. Tried to export into a format suitable to read into Freecad and close with .dxf but at least worked so slowly it was not useful, STL produced a square the shape of the circuit board which may have some use, maybe I did not investigate all possibilities. 2D or 3D CAD export is not important for me but would probably have used if it worked, need to get dimensions of enclosure correct but it's rather simple to draw a shape the form of the circuit board in CAD program so no big issue, no need for a nice picture in a presentation.
 
Are not sure about possibilities to import geometry in .step file format into FEM solver but did not find anything immediately for neither Openems or Fenics. Meshing if more or less separated from solving, know it is possible to import mesh into Fenics but if I remember correct geometry is worse, then I used it I entered geometry directly into one of the modules for Fenics using boolean operators, circles and squares, ideally this would have come from CAD software.
 
 
Have not forgotten about my task on Openems but available time have been a problem.
 
 
Nicklas Karlsson
 

Reply subtree:
4245 Re: [pcb-rnd] bugreport: mesh from N <ni...@gmail.com>
  4249 Re: [pcb-rnd] bugreport: mesh from ge...@igor2.repo.hu