Static Snubbers - CAESAR II - Reference Data

CAESAR II Applications Guide

Reference Data

Static snubbers are translational restraints designed to provide resistance to dynamic loads such as seismic and wind. Snubbers are activated by checking the Snubbers Active? check box for the appropriate load case (the one that contains the occasional load) on the Load Case Options tab in the Load Case Editor. The figure below shows that snubbers will be active in load case L2 to restrain the pipe against the uniform load.

Static snubbers, or static analysis snubbers, have SNB following the translational direction that displays in the restraint Type box (located on the Classic Piping Input dialog box). After you enter a snubber, Gap and Mu are no longer available.

Static snubbers can be directional. That is, they can be preceded by a plus (+) or minus (-) sign. To model static snubbers, follow the steps below.

  1. Run the operating case without defining a snubber.

  2. Note the displacements, in all six degrees of freedom, at each snubber location.

  3. In the Classic Piping Input dialog box, add each snubber with a distinct CNode.

  4. Place the displacements from Step 1 on all snubber CNodes.

  5. Modify the load cases by including D1 everywhere that T1 displays.

  6. Activate snubbers in the Load Case Editor for all load cases containing occasional loads.