Can any one will guide me how CAESAR

Default stiffness

Hanger stifness :1.7512e+011
Translation Stiffness:1.7512e+011
Rotational Stiffness:6.4736e+015

Is calcualted.

It's not calculated, it was set. We needed a "big number", much larger than the pipe stiffness, but not so big as to introduce numerical instabilities in the solution.

CAESAR II is a US units program. We use 1.e+12 for all three numbers when Units File=English. Translational stiffness is in pounds per inch and rotational stiffness is in inch-pounds per degree.

Your translational stiffness must be in Newtons pre millimeter. To convert from pounds per inch to Newtons per millimeter, you multiply by 0.175120.

I find your Rotational Restraint Stiffness interesting. My default value is 1.1298e+11 when I run European units. (To convert from inch-pounds per degree to Newton-meters per degree, I multiply by 0.175120.) Maybe you are running in Newton-millimeters per radian? But as Rich says, it's just a big number.

om123,

You might also consider the units for the default values. While you probably are using metric units, the CaesarII default values in English units are 1E12 lb/in. as a simple number.
That should help to understand the 'selection' of value, in place of the decimal point conversions of lb/in. to your metric units.

Hi
Can I reduce the Translation Stiffness:1.7512e+011. If I reduce the value nozzle load are within allowable limit and we are not aware of the stiffness value. Please some one advice me.

Better to use nozzle flexibilities. At least you can justify somehow why you are using lower values for the nozzle stiffness. Just because you have to justify why you are not using the default values.

If I well remember other programs use 1.e+10 for translation stiffness.

Note that this change will affect all anchors, even the ones with Cnode, ie maybe flange connections.
For small sizes, maybe it is not important but once I imported a 48" system from other software and I didn't realize why is different from mine modeled in Caesar. Then I saw the stiffnesses.

What do you plan to reduce it to? In my opinion, if you really don't know, stay on the conservative side. Meeting the nozzle allowable is not a good justification to reduce the stiffness of all restraints to a value that works for you.

As suggested by danb, use nozzle flexibility at the location if you want. That way you localize the tweak to one location at a time instead of globally. I would also suggest investigating if you can model the stiffness of specific supports. And especially if your temperature is high, consider using Eh for nozzle load qualification load case.