Main Content

vertexBC

Boundary conditions on geometry vertex

Since R2023a

expand all in page

Description

A vertexBC object specifies the type of boundary condition on a vertex of a geometry. An femodel object contains an array of vertexBC objects in its VertexBC property.

Creation

Syntax

model.VertexBC(VertexID) = vertexBC(Name=Value)

Description

model.VertexBC(VertexID) = vertexBC(Name=Value) creates a vertexBC object and sets properties using one or more name-value arguments. This syntax assigns the specified structural boundary condition to the specified vertices of the geometry stored in the femodel object model. For example, model.VertexBC([2,5]) = vertexBC(Constraint="fixed") specifies that edges 2 and 5 are fixed boundaries.

example

Input Arguments

expand all

Vertex IDs, specified as a vector of positive integers. Find the vertex IDs using pdegplot with the VertexLabels value set to "on".

Data Types: double

Properties

expand all

Standard structural boundary constraint, specified as "fixed".

Data Types: char | string

x-component of enforced displacement, specified as a real number or function handle. The function must return a row vector. Each element of this vector corresponds to the x-component value of the enforced displacement at the boundary coordinates provided by the solver. For a transient or frequency response analysis, XDisplacement also can be a function of time or frequency, respectively. For details, see Nonconstant Parameters of Finite Element Model.

For axisymmetric models, this property contains the radial component of the enforced displacement.

Data Types: double | function_handle

y-component of enforced displacement, specified as a real number or function handle. The function must return a row vector. Each element of this vector corresponds to the y-component value of the enforced displacement at the boundary coordinates provided by the solver. For a transient or frequency response analysis, YDisplacement also can be a function of time or frequency, respectively. For details, see Nonconstant Parameters of Finite Element Model.

For axisymmetric models, this property contains the axial component of the enforced displacement.

Data Types: double | function_handle

z-component of enforced displacement for a 3-D model, specified as a real number or function handle. The function must return a row vector. Each element of this vector corresponds to the z-component value of the enforced displacement at the boundary coordinates provided by the solver. For a transient or frequency response analysis, ZDisplacement also can be a function of time or frequency, respectively. For details, see Nonconstant Parameters of Finite Element Model.

Data Types: double | function_handle

Examples

collapse all

Open Live Script

Specify fixed boundary conditions for an femodel object representing an axisymmetric static structural problem.

Create a rectangular geometry that represents a spinning disk. The inner radius of the disk is 0.05, and the outer radius is 0.2. The thickness of the disk is 0.05.

gm = decsg([3 4 0.05 0.2 0.2 0.05 -0.025 -0.025 0.025 0.025]');

Plot the geometry with the vertex labels.

pdegplot(gm,VertexLabels="on");
xlim([0.04 0.21])
ylim([-0.03 0.03])

Figure contains an axes object. The axes object contains 5 objects of type line, text.

Create an femodel object for solving a static axisymmetric structural problem, and assign the geometry to the model.

model = femodel(AnalysisType="structuralStatic", ...
                Geometry=gm);
model.PlanarType = "axisymmetric";

Fix the axial displacement at vertices 1 and 4.

model.VertexBC([1 4]) = vertexBC(Constraint="fixed");
model.VertexBC
ans = 
  1x4 vertexBC array

Properties for analysis type: structuralStatic

Index    Constraint    XDisplacement    YDisplacement
  1        fixed            []               []      
  2          []             []               []      
  3          []             []               []      
  4        fixed            []               []      

  Show all properties

Version History

Introduced in R2023a

See Also

Objects