StructuralSurfaceActionFree

Free surface load

The Free surface load is related to slabs. The load is not defined by the entity it acts on, but by a specific load border. Free loads are defined by means of "loading entities" that may overlap or affect one or more slabs.

Specification in the excel:

Name of the column header
Type of data
Value example or enum definition
Required value
Description
Name
String
FF1
yes
Human readable unique name of the force
Direction
Enum
X
Y
Z
yes
Specifies the base direction of the load
Type
String
Standard
no
This property defines what the load is caused by, E.g. Standard, Wind, Snow, Self weight, Hoar Frost, Predefined, Plane Load, Water Pond, Water Pressure, Soil Pressure, Generated Water, Generated Soil
Distribution
Enum
Uniform
DirectionX
DirectionY
DirectionXY
yes
The load may be either constant across the slab or linearly variable
"DirectionX" and "DirectionY" enums are defining that, the value of the surface load is linearly variable according to the one of the user-selected axis
"DirectionXY" value inclination of surface load is defined in both directions well
q [kN/m2]
String
-10
(for "Distribution" set to "Uniform")
or
C1:-5; C2:-7
(for "Distribution" set to "Direction*")
or
C1:-3; C2:-2; C3:-1
(for "Distribution" set to "DirectionXY")
yes
Specifies the size of the load in kiloNewtons per square meter.
if Distribution is Direction X, Direction Y or Direction XY then the vertexes of the polygon of the free load have to be specified. For distribution Direction X and Direction Y two vertexes, for distribution in Direction XY, three vertexes. The format have to be following:
C"number of vertex of the load polygon" : "value of the load in this vertex"
The number of the vertex corresponds to the coordinate order. So the first coordinate means C1, the second C2 and so on
For further understanding of "C" attributes see notes below table
Load case
String
LC5
yes
The name of the load case to which the force belongs
Coordinate X [m]
Double
0.000; 2.050; 4.850; -2.000
yes
The list of X coordinates of the nodes which define the geometry of the surface free load. Each coordinate is separated by semicolon and space.
Coordinate Y [m]
Double
0.500; 1.050; 2.650; -1.500
yes
The list of Y coordinates of the nodes which define the geometry of the surface free load. Each coordinate is separated by semicolon and space.
Coordinate Z [m]
Double
0.000; 0.000; 0.000; 0.000
yes
The list of Z coordinates of the nodes which define the geometry of the surface free load. Each coordinate is separated by semicolon and space.
Edges
String
Line; Line; Line; Line
yes
Defines shape of the curve between two next nodes. Supported strings are: Line; Bezier; Circle arc; Parabolic arc; Spline. The names are separated by ; (semicolon) and space.
Coordinate system
Enum
Global
Local
yes
Defines co-ordinate system of the member in which the load is applied
Location
Enum
Length
Projection
yes
Specifies whether the load is "put directly on an inclined 2D member" or whether the "projection on plan" is defined.
Id
String
39f238a5-01d0-45cf-a2eb-958170fd4f39
no
Unique attribute designation

Notes

When is "Distribution" set to "DirectionX" or "DirectionY" the system is the same, but only two C values have to be defined.
When "Distribution" is set to "DirectionXY" is necessary to define 3 "C" vertexes. These Vertexes are defining projection onto slab and Value of the load as well. According to position and load value of "C" vertexes is load plane defined and every other vertex of the surface load is calculated. See example below.
Last modified 10d ago