Project buckling settings
Project buckling settings are always available in any type of project. If the user does not define them themselves, the application default values are used in the calculations. The application default values can be reviewed and changed using the procedure to specify the project buckling settings that is described later in this paragraph.
These project buckling settings are used as default values for every new buckling group.
The project buckling settings are defined separately for each material used in the project. In other words, there are separate project buckling setting for steel members, for aluminium members, for timber members, etc. Even though the number and type of the setting may vary for individual materials and individual national codes, the principle of their input is always the same.
It is important to keep in mind that the application defaults were defined without any knowledge of the project in which they are applied. SCIA Engineer is so versatile program that can be used for countless types of projects that it is practically impossible to come up with application default values that would suit all possible practical projects. Therefore, it is the USER who MUST review the application default values and define appropriate project buckling settings. Alternatively, if the character of the structure is such that project buckling settings are not practical and that buckling groups (BG) must be defined for every member, the application default values may be kept unchanged as they will be overwritten by the buckling group. But once again, it is the USER who MUST make this decision and who is RESPONSIBLE for correct and full definition of buckling settings.
The procedure to specify the project buckling settings
1. The required material must be selected in the Project data dialogue. Only then the corresponding service appears in the main tree menu.
2. Open the service for the required material (e.g. Steel, Concrete, Timber, etc.).
3. Find function Setup related to 1D members:
a) Steel > Beams > Setup or
b) Concrete > Setting per member > 1D buckling data or
b) Concrete Advanced > 1D Member > 1D buckling data or
c) Aluminium > Beams > Setup or
d) Timber > Setup.
4. Open the tab or page reserved for the buckling settings. Most often it is called Buckling defaults. Some other settings can be found on other tabs.
5. Input the required project default values.
6. Confirm with [OK].
7. If necessary, repeat for other materials.
Project buckling settings for steel members
The pictures above demonstrate the buckling-related project buckling settings for steel members. However, in general, the buckling-related project settings are code-independent. Detailed explanation of individual parameters can be found in the Steel Code Check manual. Nevertheless, to explain the relation between the project buckling settings, buckling groups, they will be briefly summarised here as well.
1 Buckling systems relation zz
This parameter defines whether the buckling system for flexural buckling is unique or identical to the yy buckling system.
2 Buckling systems relation yz
This parameter defines whether the buckling system for torsional(-flexural) buckling is unique or identical to another buckling system (yy, zz).
3 Buckling systems relation lt
This parameter defines whether the buckling system for lateral-torsional buckling is unique or identical to another buckling system (yy, zz, yz).
4 Deformation systems relation def y
System length for deformation in the direction of the local y-axis (strong axis).
5 Deformation systems relation def z
System length for deformation in the direction of the local z-axis (weak axis).
6 ky factor
This parameter specifies if the major axis effective length factor is to be calculated by the program or if it will be input by the user or if the user specifies directly the buckling length.
7 kz factor
Ditto for minor axis.
This field is relevant for lateral-torsional buckling check. It makes it possible to consider destabilising loads in moment factors for LTB. Destabilising loads are loads that act above the level of the beam’s shear centre and are free to move sideways with the beam as it buckles (and produce a disturbing effect).
9 Sway type y-y
The sway type is used to determine the relevant buckling factor k.
10 Sway type z-z
The sway type is used to determine the relevant buckling factor k.