Single Gusset Support Lugs

[tonycola]

Compress provides calculations for support lugs with double gussets.
Are there any plans to add the capability to analyse support lugs with single gussets?

 

[TomBarsh]

At this time there is no plan to provide an option for single gusset. The only difference between this design and that provided by COMPRESS is how the thickness of the base plate would be determined. So, you could model the lug as the COMPRESS standard and then determine the base plate thickness by hand.

Briefly, COMPRESS determines the thickness of the base plate by treating it as a rectangular plate supported on 3 sides, the fourth edge is 'free'. The load is appplied as a uniformly distributed load. The rules of Timoshenko's "Theory of Plates and Shells" are applied (see "Formulas for Stress and Strain" by Roark) to find the maximum stress, which is set equal to the allowable stress to determine the required thickness.

A similar approach would be followed for the case of the single gusset. The solution is more complex though due to the support (edge) conditions. If we're all lucky, there is a solution (to the differential equation) already available in Timoshenko or Roark. If not, well...

Note that COMPRESS will currently design support lugs without the top plate by simply entering "0" for the width of the top plate.


Tom Barsh
Codeware Technical Support

 

[TomBarsh]

Oh, please don't do what another user recently tried. They specified the distance between the gussets as "0". This lead to unrealistic results and some other problems which I don't remember off-hand. In any case, COMPRESS continued to apply the analysis for base plate thickness as discussed above. Of course, due to there being "0" span, the required thickness was essentially 0.

Tom Barsh
Codeware Technical Support