I would like to know how to model a tangential nozzle in order to get reasonable forces and moments out of CaesarII.

I would like a comment from a Caesar person or Richard about the suggestion of adding a 1/4" element as suggested in figure 3.92 of this link Modelling Nozzles for Flexibility Calculations

The reason behind the 1/4" element is because WRC was developed for 90 deg cylinder/cylinder intersections. The 1/4" element conforms to this assumption, but lets you add the following pipe element in whatever direction necessary.

Thank you for the quick answer.
1. Can you clarify the best way to model a tangential nozzle or any offset nozzle.

2. What if I have a tangential branch connection. Example: 20" pipe with a 4" tangential branch. Would I model it the same way as a nozzle?

2. Interesting about the 1/4" element, very clever.

"Best" is relative and isn't the right question. Instead, you need to know your options.

Option 1: Assume no flexibilities and treat it as a normal WRC calc as shown.

Pros: Fast. Less expensive.
Cons: Potentially wildly inaccurate, both over-conservatively and under-conservatively.

Option 2: Calculate flexibilities via WRC, apply them, and treat it as a normal WRC calc as shown.

Pros: Still fast. Equally less expensive. Less over-conservative.
Cons: Still potentially wildly inaccurate, and still and maybe more under-conservative.

Option 3: Assume no flexibilities, plug loads into facilitated FEA software and calculate stresses.

Pros: Less fast. More expensive. Unlikely to be under-conservative see commentary under option 4.
Cons: Over-conservative, but less so that option 2 and 3. See commentary under option 4.

Option 4: Calculate flexibilities in canned FEA software. Plug into CAESAR. Pull loads out of CAESAR. Calculate stresses.

Pros: Even less fast. Confusion as to what proper flexibilities should be. More expensive. Most accurate thus far.
Cons: Is still a gross simplification of reality. Imagine flexibilities being provided as kx, ky, kz, krx, kry, and krz. These are calculated indiivudally as the average spring value over dx=0 to dx=fail. dy=0 to dy=fail. dz=0 to dz=fail. etc.

In reality, this spring value isn't going to be linear. In reality they will be a function of not only their own respective displacement, but also displacements in other directions. E.G. kx = f(dx, dy, dz, drx, dry, drz).

Not only displacements, but also temperature. Not only temperature, but also pressure.

But those options are not available to us.

Option 5: Full blown FEA of all things to be considered.
Pros: Most accurate.
Cons: Most Expensive. Also usually requires splitting the load with simplified FEA (e.g. CAESAR). Also hardest to ensure that you've captured all potential combinations.

Option 6: AI calculation of all said scenarios.
Pros: Most accurate.
Cons: Doesn't exist.

Michael,
Thank you for the detailed answer, well done.

I had no plans on trying to use WRC, since WRC is not applicable.

My plan was option 3 with Caesar providing me with some indication of the forces and moments at the junction. Then use FEA to determine the stresses.

However you have indicated some items for me to consider in my approach. Thank you for the answer.

Tom,

I would estimate that 90% of the time, that is my approach, with including flexibilities from the analysis making up the final 10% when even that doesn't work.