Friction Stiffness

Dear All,
While pressing F1, Help for frictional stiffness in Configuration file i came across this paragraph from Caesar


"If the structural load normal to a friction restraint is less than the restraint load multiplied by the coefficient of friction, the pipe will not move at this support – this restraint node is "non-sliding." To model the non-sliding state, stiffnesses are inserted in the two directions perpendicular to the restraint's line of action to oppose any sliding motion."

Can someone explain
1. what Caesar means by Structural load
2.What differnce between structural load and restrain load .

Regards

There is a section in the User's Guide that discusses friction and how it is implemented in c2.

By "structural load" we mean the load acting on the restraint during the solution. When the load case converges, this is also the restraint load.