Material improvements

A forum to discuss the implementation of a good Materials system in FreeCAD
User avatar
bernd
Posts: 11655
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: Material improvements

Postby bernd » Mon Oct 19, 2020 2:03 pm

How about this? Is someone able to start the dev branch of eivind? How about a rebase on latest master?
User avatar
aomanchuria
Posts: 31
Joined: Fri Oct 09, 2020 3:13 pm

Re: Material improvements

Postby aomanchuria » Mon Dec 28, 2020 7:56 pm

I've been reading this thread with some hope that an update is coming? I'm looking for a way to describe different CTEs at different temperatures for FEM on a material card. I think that this is important enough that it needs to be on someone's radar. Properties change with temperature. For example, ultimate strength.... it may be that your particular material has a higher UTS ultimate tensile strength if its warmer than room temp. Such as refractory materials for example like molybdenum.

Another example is dissimilar CTE bonding of materials. For example soldering two metals with a glass. The glass in this case would melt at low 300-500C while the metal would melt at 1000+C temp. But the glass transition affects the properties of the glass tremendously so it is interesting to investigate the residual stress after the materials have cooled. This is for example used in microchip design, light bulb connectors, vacuum passthroughs, syringe design and really many other use cases where two dissimilar materials are bonded and the temperature is a factor that affects the CTEs.

At the moment, I think the only way is to go into the input file to Calculix and manually add different property changes at different temperatures. It would be nice if that info came from a materials card that I could re-use every time.