Design Briefs and Member Design Groups

Design groups are created to facilitate in the application of a single design check to multiple members. A member can only exist in one group since the Axial with Moments and Appendix-G stability design check may only be applied once to a member. The member design groups enable design checks, input data, and section changes to be globally applied to all members in the group.

Automatic Design Briefs

Upon initially entering MasterPort design with a generated frame the following integrated design briefs are automatically applied, creating default member design groups.

1.Elastic Critical Load Factor check applied to all members

2.AutoSize main portal members

3.Axial with Moments applied to Group 1 (External Columns)

4.Appendix G – stability check applied to Group 1 (External Columns)

5.Axial with Moments applied to Group 2 (Outside Frame Rafter members)

6.Appendix G – stability check applied to Group 2 (Outside Frame Rafter members)

7.Axial with Moments applied to Group 3 (Inside Frame Rafter members)

8.Appendix G – stability check applied to Group 3 (Inside Frame Rafter members)

9.Axial with Moments applied to Group 4 (Internal Columns)

The members are attached to each design brief, i.e. the member design groupings are only suitable for standard single or multi-bay portals of the type produced by the portal frame generation template.

In frames where additional members or nodes have been added after the automatic generation stage, the initial member groups should be cleared and redefined by the user.

Note:- The members to which a design check applies (and hence the member group) are stored internally along with the Axial with Moments check. In essence a member group is attached to a design brief. If the Axial with Moments check is deleted, then the attached member group will also be deleted. A member group cannot exist or be created without an Axial with Moments check being applied to at least one member in the group.

The automatic design briefs above apply to the main portal members. Additional design groups are provided for the other elements of the frame, including gable frames, roof bracing , wall bracing, mezzanine floors, etc. Their design will be considered later.

Working with existing Member Design Groups

As previously stated, for non-standard portal frames it may be necessary to redefine all, or some, of the member groupings. To view member groups select the Portal Frame Design Groups button , or go to the lateral restraint tab in an axial with moments check. To move between member design groups use the next and previous arrows on the MasterPort toolbar

A member design group can be:

1.Cleared:  The design check will have no member attached to it. The design check itself still exits, and a member may be reattached to it, hence redefining a member design group

2.Deleted:  The design check associated with the member design group is deleted, and the group no longer exists. The members in the design group will have no design check applied to them until they are reassigned to another group.

3.Edited: A member can be moved from one group to another but cannot co-exist in more than one group.

To clear a member group:

1.Select the Portal Frame Design Groups button from the MasterPort toolbar

2.Use the previous/next controls to navigate the member design groups

3.Select the  to clear the current group or the  button to clear all member design groups

The design briefs and associated member groups are still present, but are not applied to any members since the groups are empty.

To redefine a cleared member group:

1.Select the Portal Frames Design Groups icon from the MasterPort toolbar

2.Ensure that the cleared (empty) group is active by using the navigational buttons

3.With the Apply Current Brief button enabled by clicking in the Members in this Group box, click on the members in the frame graphics area to add to the group

4.Upon clicking on a member to add to a group, a prompt appears. To avoid this, check the “Do not prompt…” box

By adding members to a group we are effectively applying the attached design checks to those members. If a member, which is present in another group, is added, then the member is simply moved to the current group.

To delete an existing member design group:

1.Select the Portal Frames Design Groups button from the MasterPort toolbar

2.Ensure that the group to delete is active by using the previous/next buttons

3.Click the scissors button  to delete the current group, i.e. removing the associated design checks.

Applying Additional Design Groups

Axial with Moments only:

1.Select the Portal Frames Design Groups icon from the MasterPort toolbar

2.Select the

3.The mode will have automatically changed to Apply Current Brief . To add members to the new design group simply individually click on the members in the frame graphics area.

Axial with Moments and Appendix-G Stability Checks:

1.Select the Portal Frames Design Groups button from the MasterPort toolbar

2.To include an Appendix G (Annex B-B) check with the Axial with Moment design check, tick the box to include the Appendix G 

3.The mode will have automatically changed to Apply Current Brief . To add members to the new design group simply individually click on the members in the frame graphics area.

Deleting or Applying an Appendix-G in an existing design group:

1.Select Portal Frames Design Groups icon from the MasterPort tool bar .

2.Select the group to add/delete Appendix-G using the controls

3.Tick/untick the Include Appendix-G box

4.The Engineer should note that for Appendix-G Stability restraints to become active, lateral restraint positions must firstly be defined. This is most easily achieved by specifying an equal spacing value in the Design Group/Restraints or Lateral Restraints tab.

The Appendix-G Stability check obtains its member grouping and purlin spacing information from the previous design check in the design brief listing. Therefore the Axial with Moments and Appendix-G Stability checks appear consecutively in the design brief listing.

The design briefs position in the list may be changed using the sort briefs control to move the current brief up or down the listing. Where Axial with Moments and Appendix-G are applied together the briefs are moved in conjunction to maintain correct correspondence between the two.

Design briefs can also be added by selecting them from the Integrated Design menu, as described in MasterKey Steel, section 4 Design Briefs. The Engineer must take care to position the Axial with Moment and Appendix-G check consecutively in the design brief listing, by either applying the checks in the correct order or by using the sort briefs control to correctly arrange the briefs. To avoid such complexities it is recommended to always apply/remove Axial with Moment and Appendix-G design checks using the controls provided in the Design Groups/Restraints tab.

By the use of member design groups the number of design briefs and required input data are greatly reduced, as one design brief applies to all members in a group.