Hope someone can help me out.

I'm trying to model a pipe coming off a point on a 90 deg elbow. (see attached "elbow with nodes.pdf").

The model in question is a horizontal 30" line with a 12" line going up vertically (approx. 3'-0") from the midpoint of the elbow (node 17 to node 50) and intersecting back into the 30" line at node 35. When I model the system, it looks like the figure in attached "elbow with nodes_3D.pdf". I get an error message that nodes 70 to 80 missed the intersection by x=13.18",y=13.18". I thought by using offsets that might work but it didn't.

Any help would be appreciated.

Hi Will,

I believe the issue is that, although Caesar creates near, mid and far node numbers for the purposes of calculating forces/moments/stresses, all of the node numbers associated with that bend have the coordinates of the point in-line with the two pipe runs. So whenever you try and connect anything to one of these nodes, the connection point isn't actually where the real bend would be.

The best way I can think to create a node on the elbow where you really want it is to use rigid elements to connect the bend node coordinates to the real bend mid-point location (as I've shown in the attached picture).

I hope this helps.

Thanks. I was wondering if that was a way to do it.

If I want to "branch" off a bend, I would establish a new node number at the intersection of the bend centerline and the "branch". As a hard node number, the branch will be properly located, both mathematically and graphically.
To add this new node - draw your bend arc, place the node on the arc and then run a tangent line through this point. Where this tangent line intersects the tangents in and out of the bend, you will establish node numbers for the two new bends that replace your single bend.