Attribute Area

SOF_SE_ATTRIBUTE

Command	Create Attribute Area
Tooltip	Creates an area representing changes of attributes of overlapping structural areas.
Ribbon	None
Menu	None

SOF_SE_ATTRIBUTE_M

Command	Modify Attribute Area
Tooltip	Modify attribute areas.
Ribbon	None
Menu	None

TOOLTIP Creates an area representing changes of attributes of overlapping structural areas.

Summary

Attribute Areas are planar or curved surfaces which are used to selectively overwrite the properties of overlapping structural areas.

Attribute areas can be placed freely within a single structural area or overlap the geometry of several structural areas. The properties are applied during mesh generation.

On export, the properties of an attribute area overwrite those of the structural area they are defined upon. With this command, attribute areas can have different geometry and can apply to multiple structural areas.

A detailed description of these properties can be found in the chapter ‘SAR – Structural area’ of the manual SOFiMSHC.

For creation of attribute areas, the following options are available for use:

Elements

Creates structural elements from AutoCAD elements. This option supports the creation of structural elements from regions, solids, 2D areas and other 3D AutoCAD bodies. Thus almost any geometry can be used as a basis for a structural element.

Segment on geometric axis

Creates elements with reference to an axis. For this option the following input possibilities are available:

Between all placements: The elements are created from the first placement of the axis up to the last.

Use the segment closest to the picked point: One element is created between the two placements nearest to the picked point on the axis.

The grip points of elements bound to an axis change their type. Instead of the square a small arrowhead can be seen. This arrowhead can be dragged to another placement. This changes the assignment of the element.

Pick Lines or Curves–Select Points

Creates a closed polygon as the boundary of the element. When selecting lines or curves, the input type can be switched between either option by pressing the down key (as shown in the command line and at the cursor text). The picked points can be selected from the drawing or can be entered using cartesian coordinates. During input, a preview is available. The input can be ended by pressing the enter key. In a 3D system, this option is only available for use in the XY plane, although this need not be in the plane located at the origin.

After selection of a line or curve using the Pick Lines or Curves option, it can be useful to select a point by which the end of the next line is defined. The Pick Points option is available in the context menu during input.

Rectangle

Creates a rectangular element with the input of two diagonally opposite points. In a 3D system, this option is only available for use in the XY plane, although this need not be in the plane located at the origin. Please note that the rectangle will always be created with reference to the current coordinate system. If a rotated rectangular area is to be created, the coordinate system must first be modified accordingly.

Point in Area

Creates a closed polygon as the boundary of an element. A point within a closed polygonal element can be input. The boundary lines of that closed element are used as the boundary for the element. Ensure that the boundary is closed and that the point selected is not too close to a re-entrant corner, since the program, in this case, may be unable to find the boundary. In 3D systems, this option is available only in the plane where the origin is currently defined.

Set Working Plane

Because certain selection options only are available in the current working plane, it is possible to rest the working plane to a user defined position. For this the following options are available:

3Points: The coordinate system is defined using three selected point for the origin, X-axis and Y-axis.

Element: The orientation of the coordinate system is set with the selection of an object.

Database: Restores the coordinate system which is specified in the system information dialog

The working plane remains in place until the command to create the element is closed.

General Tab

Each element is given a name and a number that is shown in the drawing. This is the internal number of the element which is used for identification.

Attribute areas can have a variable thickness. For this, the thickness of the attribute area should be set as Zero and additional structural pointswith information (see Structural Point) for the area thickness can be defined and inserted on the area’s perimeter.

Meshing Tab

An attribute area can be used to alter the mesh density for a defined area.

Support/Bedding Tab

In this tab, support and bedding values for the created structural area elements can be defined (although not for the boundary of the area).

Activating the radio button Beddingfactor as Material will set the bedding values specified for the structural area’s material to be used.

The effect of a loss in tensile strength of the bedding can only be calculated with a non-linear analysis with the program ASE. The mixing of global and local support conditions is possible only in a limited manner. For example, if a global direction support condition is selected, the local direction supports will become unavailable but the local moment supports may be used. Supports unavailable for use will be automatically greyed out by the program.

Geometry Tab

In 3D or 2D prestressed slab systems, the position of the area element in relation to its nodes can be defined. Because of the normal force effects, the calculation can only be carried out using the program ASE.

The calculation of internal forces in an orthotropic panel is described further in the TALPA and ASE (Chapter 2: Theoretical Principles) manuals. The orthotropy of a panel can be controlled directly by the specifying thicknesses or by specifying a cross section.

In this case, the orthotropic behaviour option should be activated and a cross section entered for TX and/or TY orthotropic thickness values. The input possibilities for the panel thickness will then be greyed out. The stiffness of the cross section is taken over a 1m width (in the local direction of the panel). For the self-weight of the element, this input is not considered.