Restraint Stiffness

Dear all,

whether the restraint stiffness differs for the linear and non linear method ??

If so, what will be stiffness value for Hanger,translational & rotational restraints.


Non-linear boundary conditions (directional restraints, friction, gaps, or large rotation rods),

1) W+T1+P1
2) W+P1
3) L1-L2 (EXP)

linear boundary conditions
1) W+T1+P1
2) W+P1
3) T1 (EXP)

Regards,
BVK

For the non linear restraint, the stiffness is a function of displacement, in the sense that if the pipe touches the support the stiffness is the default stiffness or else it is zero.So a one word answer to your question is no.
For Frictional non linearity, the concept of default stiffness does not change, however the analysis method is little bit different ( you can read about the same in the Technical Reference manual in tecchnical discussions).

To know more about hangers , again read technical reference manual ( technical discussions).

The origin of the method of using high stiffness springs to model restraints can be found in any standard text book on Finite Element Method or Structural Analysis, which I would advise you to read.

Regards