Working on an FEA of a large steel welded structure, designed elsewhere, using SW Simulation, I found that some u-channels had been designated as beam elements, such that when displaying structural deflections the beam did not display realistically. Structural deflections were shown OK.
In order to present a more realistic display, I converted the beams to solid elements, whereby the structural deflections quadrupled!!!!
Local Solidworks Support team seem unphased by this and consider the two studies to be different and not related.
My naive understanding was that a beam element is used as an approximation to speed up the FEA and I expected the structural characteristics to be very similar.
SW Support team advise that the difference arises because the u-channel contacts several other members along its length. These are not taken into account when computed as a beam.
Surely if this were true the overall deflection would be greater, not less.
Where am I going wrong?