Point supports

There are three basic types of point supports in SCIA Engineer. Each of them, however, can be of many different configurations.

Standard support	$image\Wnd_Support_Node_Std.gif$	This support is defined by six separate parameters. Each parameter defines the constraint in one direction: translation in X, Y, Z axis and rotation around the same axes.
Foundation block	$image\Wnd_Support_Node_Block.gif$	This support is modelled by means of a foundation block. In addition, some parameters related to the surrounding soil are defined as well.
Column	$image\Wnd_Support_Node_Column.gif$	This support is used to model the case where the supporting is realised by a column.

Standard support

A standard support defines an idealised supporting restricted to a single point. The user may define the way the support acts in individual directions, i.e. in translation along and rotation around axes of selected co-ordinate system.

Free	The support is free in the specified direction. That is it imposes no constraint in the direction.
Rigid	The support in fully rigid in the specified direction.
Flexible	The support is flexible (elastic) in the specified direction. The user has to define the required stiffness of the support.
Rigid press only	Same as pure Rigid but the support acts ONLY under compression. If the support gets under tension it stops acting.
Flexible press only	Same as pure Flexible but the support acts ONLY under compression. If the support gets under tension it stops acting.
Rigid tension only	Same as pure Rigid but the support acts ONLY under tension. If the support gets under compression it stops acting.
Flexible tension only	Same as pure Flexible but the support acts ONLY under tension. If the support gets under compression it stops acting.
Nonlinear	The stiffness of the support is defined by means of a non-linear function (force-displacement diagram). For more information read chapter Parameters of a non-linear support.
Friction	The "stiffness" of the support is calculated from defined friction. See chapter Friction support.

Note: If supports of Press only type (both rigid and flexible) appear in the model, a NONLINEAR calculation MUST be executed. Linear calculation can be run as well, but it does NOT take account of the press only behaviour. The nonlinear calculation requires a definition of a nonlinear load case combination. Unless a nonlinear combination is defined, the nonlinear calculation is not accessible in the calculation dialogue.

Other parameters of a standard support

Angle

This parameter specifies the inclination of the support. The format of this parameter is:

Rx12,Ry12,Rz12

where Rx defines the inclination from X axis, and Ry and Rz define the inclination from Y and Z axis respectively. The angle is input in adjusted angle units.

Default size

This parameter defines the size of the support. The size is used to calculate the appropriate reduction of bending moment reduction on the beams in the surroundings of the support.

Note: Parameter Angle mentioned above and the adjustment of orientation described below are available for all support types, not only for the standard support.

Orientation of a support

Support in a node

A nodal support may be oriented in:

global co-ordinate system,
local co-ordinate system of the node.

Support on a beam

A point support on a 1D member may be oriented in:

global co-ordinate system,

local co-ordinate system of the node,
selected user co-ordinate system.

Foundation block

A support may be defined in the form of a foundation block. The supporting is then specified by the material and dimensions of the block together with the properties of the soil below and above the footing surface.

The support of Foundation block type requires the definition of the following parameters.

Foundation block	Selects the type of foundation block.
Foundation	Defines the properties of the soil below the footing surface.
Upper soil	Defines the properties of the soil above the footing surface.

Note: A foundation block can be used only if the Subsoil functionality has been selected in the Project settings and if material Concrete has been specified for the project.

Column

If only a part of the final structure is modelled (e.g. just one or a few floors instead of the whole building), it may happen that a support in the model is in fact a column in the real structure. SCIA Engineer enables the user to model even such situation.

The support is defined through the following parameters. The program automatically calculates the stiffness of the support.

Length	Defines the length of the supporting column.
Hinged	Says whether the column is pinned at the end or rigidly fixed.
Connection	The column may either end in the support or may continue (e.g. to another floor).
Cross-section	Specifies the cross-section of the supporting column.