Boundary Conditions of welded HSS Steel truss
Boundary Conditions of welded HSS Steel truss
(OP)
I am analyzing an already designed Steel truss. I am not 100% sure what the boundary conditions should be in Risa3D. The HSS sections are welded with a 6mm (0.25 in) fillet weld. The truss as shown is in the XY plane. What do you suggest the boundary conditions of the nodes should be? By default, all the boundary conditions are set free. This causes some instabilities in the model. The options for the boundary conditions are: fixed, reaction, spring, free..etc. Thanks in advance






RE: Boundary Conditions of welded HSS Steel truss
RE: Boundary Conditions of welded HSS Steel truss
Edit:
Hollow Structural Sections, Connections and Trusses is a good reference for this.
Also you should consider joint eccentricity, as this could increase the moment in both the chord and web members.
RE: Boundary Conditions of welded HSS Steel truss
RE: Boundary Conditions of welded HSS Steel truss
The way I think the connections should be assumed is: (Assuming a two dimensional model of the truss in the XY plane)
X Translation - Free
Y Translation - Free
Z Translation - Fixed
X Rotation - Fixed
Y Rotation - Free
Z Rotation - Free
RE: Boundary Conditions of welded HSS Steel truss
X Translation - Free
Y Translation - Free
Z Translation - Fixed
X Rotation - Fixed
Y Rotation -
FreeFixedZ Rotation - Free
For one support location (pin):
X Translation - Fixed
Y Translation - Fixed
Z Translation - Fixed
X Rotation - Fixed
Y Rotation -
FreeFixedZ Rotation - Free
For other support location (roller):
X Translation - Free
Y Translation - Fixed
Z Translation - Fixed
X Rotation - Fixed
Y Rotation -
FreeFixedZ Rotation - Free
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.