Each group set defined for a structural model is contained by the GroupSets collection stored within the Frame object.  This collection is referenced via the GroupSets property of the Frame object. 

The properties and method of the GroupSet object are summarised in the table below.

The Application, Frame, Index and Index properties in addition to the Delete method are common to many objects and are described in Chapter 2.

Each GroupSet object in this collection stores all the loads applied to the frame by that load case.  These loads are contained within one of four collections that store the joint loads, prescribed displacements, elements loads or thermal loads.

A new group set is defined within a frame using the AddSet method of the GroupSets collection.  This method has two parameters that specify the name of the group set and if the set is to use exclusive grouping of members between the groups contained with the set.  The AddSet method returns a GroupSet object referencing the group set added to the model.  A simple example of defining a group set is shown below. 

Dim mySet As Multiframe.GroupSet
 
’ Add mass to nodes
With myFrame.GroupSets
  Set myMass = .AddSet(“Floors”,true)  
End With

The name of a group set is referenced via the Label property of the GroupSet object that stores the name of the set as a string.

The type of grouping allowed within the group set is obtained from the Exclusive property of the GroupSet object.  This property is a Boolean value which is equal to true when exclusive grouping is to be applied to the groups within this set.

The Groups property provides access to the collection storing the groups defined within the group set.  The use and content of these objects and collections is described in following sections of the chapter.