Other cross-section parameters

In addition to sectional characteristics, a cross-section in SCIA Engineer has some additional parameters such as name, type description, colour, etc.

The common parameters in SCIA Engineer (except the common sectional characteristics) are:

Name	A name of a cross-section. The name must be unique within one project. If an attempt to insert a name that already exists in the project, the typed name is not accepted and is automatically changed to a project-unique name.
Type	This parameter describes briefly the cross-section type so that the user can easily and quickly see what type the particular cross-section is.
Detailed (description)	Some cross-sections (e.g. welded ones) use this item to specify the cross-section type, shape and possibly dimensions in more detail.
Material	This item defines the material the cross-section is made of.
Draw colour
Colour	This item defines the colour that is used in SCIA Engineer to draw the cross-section in the cross-section manager.
Properties editable	If this option is not selected then it is not possible to edit individual calculated sectional characteristics. If the option is ON, some of the sectional characteristics may be manually edited in order to define the cross-section whose characteristics exactly correspond to particular conditions. The properties that can be edited are:  Ay, Az, It, Iw
Buckling y-y, z-z	These two parameters determine the buckling curve types used for buckling calculations.
Fabrication	This item specifies the way the cross-section is produced.
FEM analysis	If ON, the sectional characteristics are calculated using finite element method. See separate chapter Sectional characteristics calculated by FEM. If the FEM analysis is selected, the user can specify additional parameters: Mesh size This parameter specifies the size of the finite elements used for the calculation. IMPORTANT: Please, read chapter Sectional characteristics calculated by FEM for important notes relating to the mesh size. Min. point distance Specifies the minimum distance of two FEM nodes.   In order to see the calculated sectional characteristics, click button Update.
Curve dividing	This parameter is used ONLY in concrete checks for circular and curved edges of cross-sections . When a cross-section has a curved edge, it is substituted with a polyline (composed of straight lines). This parameter specifies how many straight line segments are used to represent the original curved edge.
Use reduction factor	The user can specify reduction factors for selected properties. The property is then  multiplied by this reduction factor. For example, reduction factor k a of 0,2 will lead to sectional area of 20% instead of the full area. This reduced property is used both in checks, and in the calculation! The self weight is thus calculated with the full section while the check is executed with the reduced section. This is typically used in practice for clients who, for example, did some laboratory tests on sections. In such tests they derive a reduction factor for the surface to account for buckling effects. The full section is there in reality so they want the full section for the self weight, however the check has to be performed with the reduced area since buckling is accounted for in this reduction. The following reduction coefficients are available: k A k Ay k Az k It k Iy k Iz
Edit named items	It is possible to name selected fibres of the cross-section and use these names as reference in display of results, etc.
Edit joints	It is possible to define joints and use them later.
Edit cuts	It is possible to define sections (cuts) across the cross-section and use them later.

Special parameters for Steel cross-sections when using code EC-EN

Initial shape subgroup

For thin-walled Steel cross-sections an Initial shape is defined by default.

For a General cross-section the ‘Thin-walled representation’ has to be used to be able to define the Initial Shape.

More information can be found in the respective chapter of the Theoretical Background for EN 1993: "Initial Shape".

Initial shape

Within this dialog the Initial Shape can be reviewed.

Classification

This action runs the Classification dialog which performs the classification of the cross-section under different actions.

More information can be found in the respective chapter of the Theoretical Background for EN 1993: "Classification"

Effective section

This action runs the effective section dialog which calculates the effective section properties under different actions.

More information can be found in the respective chapter of the Theoretical Background for EN 1993: "Effective Section properties"

Advanced procedure

This option allows the use of the Advanced procedure for calculation of effective section properties.

More information can be found in the respective chapter of the Theoretical Background for EN 1993:"Advanced Procedure for Effective Shape Calculation"

 

Special parameters for cold-formed cross-sections

In case of Steel cross-sections with fabrication cold-formed the Initial shape subgroup is extended with the following settings:

Free flange geometry

This setting is visible for selected section types and shows the geometry of the free flange for use in purlin design.

More information as well as a list of supported sections can be found in the respective chapter of the Theoretical Background for EN 1993:"Special considerations for Purlins"

Restrained by sheeting

When this option is selected the cross-section is assumed to be restrained by sheeting.

This prohibits bending about the principal axis and allows only bending about the local LCS axis.

 

Cold-formed subgroup

This subgroup shows specific settings for cold-formed sections.

Average yield strength

When this setting is activated the average yield strength as defined in EN 1993-1-3 is used.

More information can be found in the respective chapter of the Theoretical Background for EN 1993:"Material properties"

Steel core thickness

When this setting is activated the steel core thickness can be set as defined in EN 1993-1-3.

The thickness of the thin-walled elements are modified according to the inputted metallic coating and all section properties are recalculated.

More information can be found in the respective chapter of the Theoretical Background for EN 1993:"Material properties"

 

Special parameters for aluminium cross-sections when using code EC-EN

Initial shape

For aluminium cross-sections an Initial shape can be defined.

More information can be found in the Theoretical background manual and in code EN 1999-1-1:2007.

If the option is selected, the following additional parameters appear in the dialogue:

Edit initial shape

Within this dialog the Initial Shape can be modified. Specifically for Aluminium sections this allows the definition of welds on the different elements.

Effective section

This action runs the analysis of the reduced cross-section. Both the classification and effective shape calculation are part of this action.

 

In addition to the numerical data available for a cross-section, the program offers also a drawing of the cross-section with marked vertex numbers. The numbers are important mainly if the user includes a cross-section characteristics table into a document where some of the values correspond to individual vertices. Therefore, it is essential to know the convention of vertex numbering. The vertex numbers are given on a separate tab of the graphical window in the editing dialogue.