How do you Simulate a welded structure with beams on top of beams?

It is easy to create a welded structure that has multiple
weldments stacked on top of each other then welded together, as seen in this
picture. 

 

The problem comes in when you need to simulate.  Since SolidWorks Simulation considers a beam as a two
node element, the interaction between the centers of the beams is
neglected.  If you have ever tried to do
simulate this it looks the like the beams pass through each other.  The other issue is that you cannot simulate a
weld joint in between them like you would a shell element to a solid
element.  For the best work around you
have mesh the weldment as a solid element and not a beam element.  Due to the accuracy of the solid element you
will get a better result.  The only drawback to this method is that your calculation and mesh time escalates
quickly. 

The second method you can use to simulate that same
structure is to take that weldment and combine all the structural members into
one member.  Then simulation will see
this as one beam member which will simulate them being welded together.  Just make sure the beam properties are
correct in the simulation tree.