cut clear Equipments

Posted by: Wolfgang13

cut clear Equipments - 06/30/15 05:25 AM

Hello,

i´m new in this forum, so please be patient with me :-)

I´m facing a problem with our FEM Analyst (ANSYS).
I want to cut clear different equipments (e.g. T-piece) and give the corresponding Loads (Forces and Moments) to the FEM Analyst.

My Model in Caesar II is (for T-Piece) with Anchor and CNode to the connecting Pipe at all three connections. The T-Piece is embedded in a Piping System.

For the FEM calculation the summ of all Forces and Moments (of the three connections) have to be zero !
Caesar II result (for one special loadcase) is not a balance of forces and Moments !

Is there another way to cut Equipments clear (free-body diagram) and transfer balanced forces and Moments to a FEM analysis.

Thanks in Advance !

Posted by: Dave Diehl

Re: cut clear Equipments - 06/30/15 07:39 AM

So, you have a Node/CNode Anchor at each tee weld? (I would specify the CNode on the Tee side of that pair since the Restraint Report shows the load ON THE RESTRAINT, or the load on the CNode, or the load on your tee.)
Those loads are the balancing loads; if this is a static analysis the system is in equilibrium.
Remember that your tee is developing its own loads - probably at least deadweight and thermal strain. Perhaps considering these loads, you will find your equilibrium.
Posted by: Wolfgang13

Re: cut clear Equipments - 07/01/15 12:40 AM

Hello Dave,

thank you for your quick response !

Yes, Anchor/Cnode is on each weld of the Tee.

I made the Anchor on the piping side (only change in direction of the forces/moments).

For the Forces i get equilibrium but not for the moments.
Loadcase Weight: Equilibrium in Forces and Moments
Loadcase Sus: Equilibrium in Forces and Moments
Loadcase Op: Equilibrium only in forces, Moments are not in balance
Loadcase Exp: Equilibrium only in forces, Moments are not in balance


Wolfgang
Posted by: Wolfgang13

Re: cut clear Equipments - 07/14/15 03:43 AM

I still have the problem !

For static analysis and loadcases with thermal influence i don´t get equilibrium.
For clarification please see attachments (simplified)
Moment Mx is in disbalance round about 6,5kNm

Does somebody have an idea what i can do to get equilibrium ?

Thanks in Advance!!!
Posted by: Dave Diehl

Re: cut clear Equipments - 07/14/15 07:11 AM

When resolving moments you must also include moments caused by forces.
Pick a resolution point and include those additional couples.
Posted by: Wolfgang13

Re: cut clear Equipments - 07/16/15 05:48 AM

Hello Dave,

thank you !!! Now i have Equilibrium.