I've modeled a truss T-connection and I'm getting a warning that the joint is not in equilibrium. Since there is no documentation that I can find on sign convention and there is no description as to what the exact problem is I'm left to guess. I've tried several experiments and only one thing worked. That was to remove all load from the branch and put a compression only load on the chord. This caused the error to go away. Of course, this doesn't help my real world problem but I'm just trying to see what will eliminate the error. Next I added in an axial load to the brace member and shears in the chord to resist it. The warning came back. I tried switching the sign of the load in the brace member. No luck.
Two request for Bentley. Please document the sign convention to be used for forces and moments and print the sum of the applied loads and moments at a joint so we can track down input errors easier.
Hello, pressing F1 in the New joint dialog or enabling the help in the connection pad will show you a figure for the forces convention. However, we realized that the figure required a tweak to be more useful and we have updated it as follows:
The validation examples are also a good way to start checking the truss connections. There you can find how forces were set for most of the common examples from the AISC DG 24 or the HSS Design Manuals.
C:\ProgramData\Bentley\Engineering\RAM Connection\13.1.0\Data\Verification Manual Examples\AISC
Answer Verified By: Tank
The figure is very helpful. When do you expect the next release of RAM Connection so we will be able to see that in the help window?
I still would suggest the summation of forces and moments be included so any error is easier to track down.
We plan to do the next release (RAM Connection v13 Update 2 (v.13.2)) late August 2019. Let us add this enhancement and see if we can make it for Update 3.