Main Content


Specify structural superelement interface for component mode synthesis



structuralSEInterface(structuralmodel,RegionType,RegionID) defines the specified geometric region RegionType, RegionID as a superelement interface for component mode synthesis. For better performance, specify geometric regions with a minimal number of nodes. For example, use a set of edges instead of a face, or a set of vertices instead of an edge.

If you intend to use a reduced-order model in Simscape™ Multibody™, use structuralBC instead of structuralSEInterface.

sei = structuralSEInterface(___) returns the superelement interface assignment object using the previous syntax.


collapse all

Define the two ends of the beam as structural superelement interfaces. The reduced-order modeling technique retains the degrees of freedom on these boundaries while condensing all other degrees of freedom.

Create a structural model for modal analysis of a 3-D problem.

structuralmodel = createpde('structural','modal-solid');

Create a geometry and include it in the model. Plot the geometry.

gm = multicuboid(0.1,0.01,0.01);
structuralmodel.Geometry = gm;

Figure contains an axes object. The axes object contains 3 objects of type quiver, patch, line.

Specify Young's modulus, Poisson's ratio, and the mass density of the material.

structuralProperties(structuralmodel,'YoungsModulus',70E9, ...
                                     'PoissonsRatio',0.3, ...

Generate a mesh.


Specify the ends of the beam as structural superelement interfaces. For better performance, use the set of edges bounding each side of the beam instead of using the entire face.


Reduce the model to all modes in the frequency range [-Inf,500000] and the interface degrees of freedom.

R = reduce(structuralmodel,'FrequencyRange',[-Inf,500000])
R = 
  ReducedStructuralModel with properties:

                     K: [166x166 double]
                     M: [166x166 double]
              NumModes: 22
           RetainedDoF: [144x1 double]
    ReferenceLocations: []
                  Mesh: [1x1 FEMesh]

Input Arguments

collapse all

Structural model, specified as a StructuralModel object. The model contains the geometry, mesh, structural properties of the material, body loads, boundary loads, and boundary conditions.

Example: structuralmodel = createpde('structural','transient-solid')

Geometric region type, specified as 'Vertex', 'Edge', or, for a 3-D model, 'Face'.

Example: structuralSEInterface(structuralmodel,'Face',[2,5])

Data Types: char | string

Geometric region ID, specified as a vector of positive integers. Find the region IDs by using pdegplot.

Example: structuralSEInterface(structuralmodel,'Face',[2,5])

Data Types: double

Output Arguments

collapse all

Superelement interface assignment, returned as a StructuralSEIAssignment object. See StructuralSEIAssignment Properties.

Version History

Introduced in R2019b