Help with weld design
Help with weld design
(OP)
Hi,
I just been asked to calculate the minimum size required for a slot/plug weld to attach a pipe to a plate. I've never designed welds so I'm new at this.
I started by reading AWS D1.1 to find the max/min allowed sizes for the slots/plugs. Then, I couldn't understand how to calculate the actual area needed so I went back to the internet and found an article about weld calculations using "Mean Stress Method". After doing the calculations I ended up with an area of 0.02 in², which I found unrealistic.
Could someone point me in the right direction or tell me the equations to find the required area?
The pipe is welded horizontally to a steel plate of 3/8" and when filled weights around 200 lb.
I just been asked to calculate the minimum size required for a slot/plug weld to attach a pipe to a plate. I've never designed welds so I'm new at this.
I started by reading AWS D1.1 to find the max/min allowed sizes for the slots/plugs. Then, I couldn't understand how to calculate the actual area needed so I went back to the internet and found an article about weld calculations using "Mean Stress Method". After doing the calculations I ended up with an area of 0.02 in², which I found unrealistic.
Could someone point me in the right direction or tell me the equations to find the required area?
The pipe is welded horizontally to a steel plate of 3/8" and when filled weights around 200 lb.






RE: Help with weld design
I would use AISC specifications for weld strengths... chapter J.
RE: Help with weld design
I made a quick draft of what I'm trying to do. The side with the pipe is hard to access when assembled, that is why we want to use slots/plugs.
I'm still going to look up the specifications you suggested.
RE: Help with weld design
And yes, that type of weld makes more sense after I saw the sketch.
RE: Help with weld design
RE: Help with weld design
RE: Help with weld design
One more thing, the structure will be summited to thermal fluctuation from around 75°F to 150°F (Delta_T = 75°F).
I calculated the thermal stress ass f=(a)(delta_T)(E) which gave me a 15ksi stress. Would this be relevant for the design?
RE: Help with weld design
RE: Help with weld design
RE: Help with weld design
serlara...your stress level is low, so you really just want to make sure that your weld doesn't screw up something else. A simple plug weld is relevant and check the AWS requirements.
RE: Help with weld design
Conservatively I would add the shear from the thermal expansion/contraction forces on to the weld shear.
I would also note that very small welds are not a very good idea as the first 0.25 to .5 inch of weld is not always fullty effective as the electrode is not always fully heated or lined up properly. I expect if you did specify a very small weld the welder would tend to make it larger for this reason.