Gimbal Joints - CAESAR II - Reference Data

CAESAR II Applications Guide

Reference Data

Gimbaled joints are designed to resist pressure thrust. CAESAR II recommends that you verify that the joint manufacturer is aware of the design loads on the gimbals. External loads are not always given. If axial loads are given, the bellows designer must know whether it includes or excludes pressure thrust.

You can model the angular-only gimbal as a zero length expansion joint with rigid axial, transverse, and torsional stiffnesses. The bending stiffness is set equal to the rotational stiffness specified in the manufacturer's catalog.

CAESAR II recommends that you thoroughly model angular and offset gimbals, as shown in the following figures. Angular and offset gimbaled joints are usually installed in large diameter lines where lumped-property assumptions for the bellows may not be within reasonable engineering accuracy.

Rigid elements between nodes 105 and 110 and nodes 111 and 115 each contain
half the weight of the hinge mechanism.