Moment Releases |
  
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Moment Releases |
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Moment Releases provide a way to specify that a member has a hinge (no moment transfer capability). They can be applied to the start end, the ending end or both ends of a member, and they can be applied about the local y axis, the local z axis or both.
Graphical Method
Moment releases can be defined and assigned graphically by clicking Create (or Modify) > Member Properties > Moment Releases. This opens the Member Releases dialog, which allows a release to be defined and then assigned to selected members.
Tabular Method
Moment releases can be defined and assigned using the tabular method by clicking Tables > Member Releases. This opens the Member Releases table, which allows multiple member moment releases to be applied at once in the table.
Caution!
Use caution not to "over-release" when applying member releases, as this can lead to model instabilities. For example, picture two members connecting at a node. If the intent is to model a hinge at that location, then only ONE of the two members should have a release applied, because it only takes one release to prevent the transfer of moment. If BOTH members were released, it could cause a stability problem, because that common node is now disconnected (in a moment transfer sense) from ANY member in the model. So mathematically, it is able to spin, and this causes an instability in the mathematical solution of the model.
