I have a system which ran OK with dynamic analysis as far as loads and stresses. I then added dynamic SAM with the response spectra. Now my loads and stresses are way over the allowables.
It seems like these loads are not realistic. When I run the system as static seismic with the SAM input as thermal anchor movements the loads are OK. Anyone else experienced problems with SAM in dynamic analysis?

Single Response ?
Multi Response ?
With discplacement at anchor movement or zero ?

It's a dynamic response spectra analysis in x, y and z. SAM's are applied at all applicable restraints in the appropriate directions. My stress increased from 5000 psi to 27,000 psi using dynamic. Not realistic. I believe the program is not working correctly in this type of application.

Find and Read "Dyn.Input spectrum results" here in this forum .
Maybe can help you.

I think if you have more as one cell for the same spectrum (example direction X)because more as one restraint node have anchor movements, then
Caesar interprets this wrong.

One solution way :
Create a static load case with the displacement and combined with spectrum load case without SAM.

I can't find "Dyn.Input spectrum results" in this forum. Is it still there?

In order to use the static load case with displacements we would need to get something from Coade that the dynamic SAM case is not working right and so far they have not chosen to add to this thread.

What sort of dynamic displacements are you getting for your restrained nodes?

Does your shock spectrum encompass the entire system or do you limit it/them to sections of your piping? If limited, did you provide displacements (the last column) for these spectra? If not, CAESAR II will calculate them for you using your input for the lowest frequency.

It appears that if you run the thermal static case and SRSS all the SAM movements you get similar results to the dynamic analysis.

You hold the same results if you combined the static case (displacemend
SAM)as dynamcic case with SAM input ?

MUL211 had 8 individual SAM vectors. When I ran each as an individual displacement set and combined these 8 by SRSS in statics, I got the same numbers as in dynamics. In dynamics I had zero shock and only SAM and SAM was combined SRSS.