Equivalent Stress in Weld

[hungrydinosaur]

Hi All,

I have attached a sketch of a welded structure, with 4 gusset plates. The structural analysis program shows the loads in the X, Y and Z direction at the beam intersection. I know it might sound basic stuff for many of you, can anyone advise what is Equivalent Stress for the welding of the gussets? As the welding are in different planes, just need some advice.

Thanks in advance.

 

[Structurecrg]

There is insufficient information here to evaluate the weld group. What are the weld sizes, weld group dimensions/section properties, base metal thicknesses, electrode, weld type (fillet?), base material yield strengths..

Further, it looks like there are (2) weld groups to evaluate. Where is the work point for these concentric forces? I assume it is at the base of the circular post? The picture resembles stiffeners for a column/baseplate, which implies there is some moment at the base of this post. Is the base of the post also welded to the top of one of the wide-flange members?

 

[BUGGAR]

If I understand, you are looking for the resultant shear on any given weld based on that resultant being equal to the square root of the X load squared plus Y load squared plus Z load squared(?)

 

[Liam Nesson]

Its funny how everybody will interpret your question differently.
If your asking what is the stress in the weld so as to size it. For the weld to the top of the w beams, one aaproach is to assume all the welds take the axial and welds with the gusset plates in the x direction take the loads in the x direction. Add these forces to get your max force in kN/mm and check against the weld capacities in your steel handbook.
Someepoints to note:
1. you havent provided any moments,this connection might not act as a pin. One of the steel r welding design books by blodgette has a section regarding welds stress on welds shapes due to moments.
2. Local yielding of the pipe may be an issue, there are a number of design guides that deal with this.

 

[Ron]

Your structural analysis program is providing orthogonal reactions to the pipe loading(presumably). As an example for designing the welds between the gusset and pipe/gusset and rolled shape, consider the lower right quadrant gusset. You have a reaction in the X and Y directions. From this you can size the vertical weld in the Y direction between the gusset and the pipe....the Y direction will be direct longitudinal shear while the X direction will be in tension. Then you can check the weld in the X direction to make sure it will handle both the shear in the X direction and the tension in the Y direction. Perform the same check for each weld in each direction.