Erik Kostson
Ansys Employee

OK, I think we need to explain more what we mean.

See this video on how you should create 3D representation of your parts.

So start a new model, and do like in the video and as shown for the first 25 seconds in the video. 1. So define the cross section (sketch), which in the video is a square section (you would need to sketch your section, say tube or I, whatever it is), and then finally extrude it (sketch of section) into a 3D part.

When you have all members defined as Peter said you will need to use Split Body to construct the intersection between the two tubes. Use the Prepare tab and click the Share button to create the weld line.