formulation of weld in proMech

[paoloz]

Hi all,


How ProMEch manage the connection "weld"? Does it consider the stresses of the weld, according to some standard formuation? Or simply connect two parts as a standard connection?


thanks,


Paoloz

 

[jabbadeus]

The weld connection is strictly for taking care of gaps in an assembly created when components are compressed down to midshells. Imagine an assembly consisting of two plates located perpendicular to one another (like a 'T'). If both parts use shell elements, when the surfaces are compressed to midshells, there will be a space between them, the meshes will be disjointed, loads and forces won't be transmitted from one component to the other, etc. The weld connection (in this case, an end weld) extends the mesh of one component to the other to eliminate these gaps.


If you're interested in getting stresses out of the weld itself, I suggest for analysis purposes modeling it as a part.

 

[oblak]

if we have two parts aligned, and then compressed to midshells, will Mechanica analyze them as two parts, or it will be assumed that they are connected??

 

[jabbadeus]

Mechanica will attempt to make automatic midsurface connections, but as I understand it, these will fail in many, most, or all cases to connect the components. So you'll have two components that aren't connected, and very likely the analysis will fail because the model is underconstrained.

 

[oblak]

and what is the best way to connect assembly of 2-3 parts. In real world they have preparation for welding, and they are welded, but in virtual world, they are only aligned, and they dont have preparation for welding.....what to do, and still use compressing to midshells...

Edited by: oblak

 

[jabbadeus]

If the components are stacked like plates, use a perimeter weld to connect them. If they come together like a T, use an end weld.


Roughly, what do the components look like?


If you are not using shell compression, in general you can just let the automatic mesher create a continuous mesh.

 

[oblak]

It is big assembly, made of plates with L, and T profiles welded on plate. If I dont use shell compresion it will take a long time to make an analysis. And if I use weld connections it will take a long time..... I will try to make a shell compresion, and no connections between parts, and i will see what will be.


jabbadeus, thanks a lot.....