Hello ,

We are calculating frictinal stiffness factor using the formula provided in caesar II help .

Kfriction= F*(mu)*Fact
where
F= force taken from the static solution.
Kfriction= stiffness of frictional restraint
(indicated in setup parameters)
mu=0.3 as used in static analyis

But if a stress system contains more than one upport then the force F is varying from support to support.In turn the stiffness factor will vary from support to support also.Whereas we have only one field to enter the factor in dynamic control sheet.

Please guide us how to resolve the problem.


Regards,

The intent is to supply a greater stiffness where there is greater friction. This appraoch does that.

This works quite well for calculating natural frequencies. I usually use 1000 as my stiffness factor for friction but find that a value of 200 works about the same.

If you are looking for that friction to carry some dynamic load (as opposed to simply calculating natural frequencies) I guess you may want to have specific control at each support but I don't think you really know what's going to be happening there anyway.

If you want to specify unique stiffnesses at each sliding support, why not model this friction restraint as individual snubbers?