Bracket

Open the Brackets dialog using either of the following methods:

• Click Geometry menu > Additional Attributes > Brackets.
• Click .

Use this option to define brackets for structure members in node zones. Brackets are used in a structure to increase rigidity of a structure member in node zones. They make it possible for these zones to carry larger moments and transversal forces, while smaller sections are used along entire members.

Note: Brackets can be applied only to I-sections. Brackets for other types of profiles (e.g. pipe profiles, C-section profiles etc.) can not be defined. During verification of the structure model, warning is displayed to inform that a bracket was defined for a profile type different than the I-section one.

There are two bracketing methods:

• Using plates of determined dimensions
• Using appropriately cut section of a given member

To define a bracket, select a bracketing method, bracket dimensions (absolute or relative values), and a bracket type (upper, lower, or at both sides). A bracket defined this way can be saved under a label you choose. Later, you can use this bracket many times in a structure. Brackets of a member are introduced separately for each member end.

The Brackets dialog lets you directly assign bracket properties to structure elements. It has an active list field, active selection field, and the standard buttons (Apply, Close, and Help). Information about the label and the type of the defined bracket is in the active list field.

At the top of the dialog:

• - Adds a new bracket type (New Brackets Definition)
• - Deletes a selected bracket type from the active list
• , , and - Displays the list of active brackets as: large icons, small icons, short list, or long list.
• - Lets you delete from the active list all the bracket types that are not used in the structure being designed.
• - Opens the Label Manager dialog.

Similar to the dialog for defining sections or supports, the process of assigning bracket properties to structure elements is divided into 2 steps:

1. Bracket type definition

   If the active bracket list is empty or a new bracket type is to be added to the active list, click New Brackets Definition:

   • If none of the bracket types is selected; clicking the New bracket icon opens the dialog for a new bracket type definition. The first tab is activated with the fields previously defined (except for the LABEL field) or default parameters are set.
   • If none of the brackets is selected; clicking the New bracket icon opens the dialog for a new bracket type definition. A tab appropriate to the selected section is activated. All fields, except for LABEL, are filled according to the bracket type selected.

     You can also open the dialog for a new bracket definition by double-clicking on the element from the active bracket list. The New Bracket dialog opens on the tab respectively to the bracket type and all fields are filled according to the bracket type selected. After changing the required parameters, the bracket is added (updated) to the active list by clicking ADD or pressing <ENTER>. If you do not change the label, an appropriate warning displays (as in the case of a new bracket definition). This option in the dialog lets you change bracket properties.

2. Bracket definition in a structure.

To delete a bracket from the structure:

1. Click on the active bracket list,
2. Select an object in the structure you want to delete the bracket from.

You cannot modify this type of bracket; it is assigned the same way as the bracket properties are to a structure element.

The symbol of the bracket displays after you add it.

Brackets are considered in successive calculation stages in the following way:

• During static calculations: The bracketed part of a member is assumed to have a section of variable inertia whose dimensions are the result of the bracket definition.
• During connection design: Bracket dimensions are automatically transferred to the connections module when a steel connection is defined. The modification makes it necessary to update the dimensions of the defined bracket or to define a new one.
• During code calculations: Certain assumptions, concerning the equivalent section parameters of a member treated as a whole, are made during code verification of bracketed members. Moment of inertia of a equivalent member is calculated on the basis of the length and the inertia of member components, that is, of the bracketed and non-bracketed member segments. Equivalent properties are used to calculate the general stability of a member. Stress verification in particular points of a member takes into account real section properties.

Design, that is, finding the optimum member sections, takes into account brackets as well.

Note: A bracket defined through relative values is automatically adjusted to the member and the section. Therefore changing the section during design, changes the bracket dimensions that depend on the section dimensions.