Friction Multiplier for Seismic Load Cases is to be considered as 0.0 instead of the default set value in CAESAR II as 1.0.
Is it allowed to change it to 0.0 for seismic (OPE) load cases?
If it is allowed then what is the logic behind it?
Why we can not take advantage of frictional resistance in the seismic events?

Hello

I really would like somebody to give any response please

Thank you

See User Manual Chapter 8 Dynamic Input and Analysis Page 8-4

Yes, we cannot take the advantage of damping in the piping system due to frictional resistance in a seismic event. Read the ALA guideline on "Seismic design and retrofit of above ground piping" chapter 8.

The friction multipier is set to default of 1, because it is used for operating cases, which could be changed to '0' for your case.

Regards,

Tank you Mr.Ohliger and Mr.SKK both.

I have gone through the documents suggested by you.
Furthermore, I have gone through L.C.Peng's paper-

"Treatment of Support Friction in Pipe Stress analysis".

Part of the paper: OCCATIONAL LOAD ANALYSIS "....Nevertheless, since the friction tends to help the system in resisting the occational load, its inclution to the occational load analysis requires some justification. The practice varies due to the difference beliefs in the availability of the initial weight load during the occational load condition."

In my job, I am considering only horizontal seismic, no vertical component.
So,practically what should be the effect of friction on support in this situation and what should be the value of Friction Multiplier?

Kindly if anybody explain it or suggest further reading if any.

Thank you.

Friction made your system stiffer, that mean the calculated frequency will be higher as without friction. Look your spectrum at the highest accelerations and the frequencies on that. Then you can decided it is conservativ or not.