Friction Stiffness - CAESAR II - Help

CAESAR II Users Guide

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English
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CAESAR II
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CAESAR II Version
12

Specifies the friction restraint stiffness. The default value for the friction restraint stiffness is 1.0E+06 lb/in.

Typical units (depending on your unit system):

  • lb/in

  • N/mm

  • N/m

  • N/cm

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.

Nonlinear convergence problems may be alleviated by reducing the friction restraint stiffness. Lower friction stiffness will more readily distribute friction loads throughout the system and allow nonlinear convergence. However, this lower stiffness affects the accuracy of the results. Lower stiffness values permit more "non-sliding" movement but given the indeterminate nature of the friction problem in general, this error may not be crucial.