NRC Example NUREG 9 - CAESAR II - Reference Data

CAESAR II Applications Guide

Reference Data

NRC Example NUREG 9

The example is a three-branch system, composed of 20 pipe elements and 14 support elements. The support elements are divided into four groups that correspond to four distinct input excitation spectra sets. This example demonstrates the independent support motion feature of CAESAR II. In modeling this problem, the 14 support elements are input as restraints with stiffnesses. All bend elements include a node at the "near" point to ensure mass and stiffness computations consistent with the NRC example. In addition to the pipe density, there is a single lumped mass applied at node 18. In this example, the contributions from the pseudo-static anchor point displacements are not included. The three solutions presented represent the following:

  • Envelope spectrum; spatial then modal combinations

  • ISM (independent support motion); directional, spatial, then modal combinations using SRSS

  • ISM directional, spatial, then modal combinations using ABS