edgeLoad

Load on geometry edge

Since R2023a

Description

An edgeLoad object contains a description of a load on an edge of a geometry. An femodel object contains an array of edgeLoad objects in its EdgeLoad property.

Creation

Syntax

model.EdgeLoad(EdgeID) = edgeLoad(Name=Value)

Description

model.EdgeLoad(EdgeID) = edgeLoad(Name=Value) creates an edgeLoad object and sets properties using one or more name-value arguments. This syntax assigns the specified structural, thermal, or electromagnetic load to the specified edges of the geometry stored in the femodel object model. For example, model.EdgeLoad([1 2]) = edgeLoad(SurfaceTraction=[0 100]) specifies the surface traction on edges 1 and 2.

Input Arguments

EdgeID — Edge IDs

vector of positive integers

Edge IDs, specified as a vector of positive integers. Find the edge IDs using pdegplot with the EdgeLabels value set to "on".

Data Types: double

Properties

Heat — Heat source term

real number | function handle

Heat source term, specified as a real number or function handle. Use a function handle to specify an internal heat source that depends on space, time, or temperature. For details, see Nonconstant Parameters of Finite Element Model.

Pressure — Pressure normal to boundary

real number | function handle

Pressure normal to the boundary, specified as a real number or function handle. A positive-value pressure acts into the boundary (for example, compression), while a negative-value pressure acts away from the boundary (for example, suction).

If you specify Pressure as a function handle, the function must return a row vector where each column corresponds to the value of pressure at the boundary coordinates provided by the solver. For a transient structural model, Pressure also can be a function of time. For a frequency response structural model, Pressure can be a function of frequency (when specified as a function handle) or a constant pressure with the same magnitude for a broad frequency spectrum. For details, see Nonconstant Parameters of Finite Element Model.

Data Types: double | function_handle

ConvectionCoefficient — Convection to ambient boundary condition

real number | function handle

Convection to ambient boundary condition, specified as a real number or function handle. Use a function handle to specify a convection coefficient that depends on space and time. For details, see Nonconstant Parameters of Finite Element Model.

Specify ambient temperature using the AmbientTemperature property. The value of ConvectionCoefficient is positive for heat convection into the ambient environment.

Data Types: double | function_handle

AmbientTemperature — Ambient temperature

real number

Ambient temperature, specified as a real number. The ambient temperature value is required for specifying convection and radiation boundary conditions.

Data Types: double

Emissivity — Radiation emissivity coefficient

number in the range (0, 1)

Radiation emissivity coefficient, specified as a number in the range (0, 1).

Specify ambient temperature using the AmbientTemperature property and the Stefan-Boltzmann constant using the femodel properties. The value of Emissivity is positive for heat radiation into the ambient environment.

Data Types: double

SurfaceTraction — Normal and tangential distributed forces on boundary

vector | function handle

Normal and tangential distributed forces on the boundary (in the global Cartesian coordinate system), specified as a vector of two elements or a function handle.

If you specify SurfaceTraction as a function handle, the function must return a two-row matrix. Each column of the matrix corresponds to the surface traction vector at the boundary coordinates provided by the solver. For a transient or frequency response analysis, surface traction also can be a function of time or frequency, respectively. For details, see Nonconstant Parameters of Finite Element Model.

Data Types: double | function_handle

TranslationalStiffness — Distributed spring stiffness

vector | function handle

Distributed spring stiffness for each translational direction used to model an elastic foundation, specified as a vector of two elements or a function handle.

If you specify TranslationalStiffness as a function handle, the function must return a two-row matrix. Each column of the matrix corresponds to the stiffness vector at the boundary coordinates provided by the solver. For a transient or frequency response analysis, translational stiffness also can be a function of time or frequency, respectively. For details, see Nonconstant Parameters of Finite Element Model.

Data Types: double | function_handle

SurfaceCurrentDensity — Surface current density

real number | function handle

Surface current density in the direction normal to the boundary, specified as a real number or function handle. The solver uses a surface current density boundary condition for a DC conduction analysis. Use a function handle to specify a surface current density that depends on the coordinates. For details, see Nonconstant Parameters of Finite Element Model.

Data Types: double | function_handle

Examples

Heat Coming Through Edge of Square

Specify a heat flux through the edge of a square for an femodel object representing a thermal problem.

Create an femodel object for solving a steady-state thermal problem, and assign the unit square geometry to the model.

model = femodel(AnalysisType="thermalSteady", ...
                Geometry=@squareg);

Plot the geometry with the edge labels.

pdegplot(model.Geometry,EdgeLabels="on");
xlim([-1.1 1.1])
ylim([-1.1 1.1])

Specify the heat flux boundary load on edge 3.

model.EdgeLoad(3) = edgeLoad(Heat=20);
model.EdgeLoad

ans = 
  1x4 edgeLoad array

Properties for analysis type: thermalSteady

Index    Heat
  1       [] 
  2       [] 
  3       20 
  4       [] 

  Show all properties

Version History

Introduced in R2023a