createpde

Create a model

Domain-specific structural, heat transfer, and electromagnetic workflows are not recommended. New features might not be compatible with these workflows. To create a recommended model for structural, heat transfer, or electromagnetic analysis, use femodel. For help migrating your existing code to the unified finite element workflow, see Migration from Domain-Specific to Unified Workflow.

Syntax

model = createpde(N)

model = createpde

structuralmodel = createpde("structural",StructuralAnalysisType)

thermalmodel = createpde("thermal",ThermalAnalysisType)

emagmodel = createpde("electromagnetic",ElectromagneticAnalysisType)

Description

model = createpde(N) returns a PDE model object for a system of N equations. A complete PDE model object contains a description of the problem you want to solve, including the geometry, mesh, and boundary conditions.

model = createpde returns a PDE model object for one equation (a scalar PDE). This syntax is equivalent to model = createpde(1) and model = createpde().

structuralmodel = createpde("structural",StructuralAnalysisType) returns a structural analysis model for the specified analysis type. This model lets you solve small-strain linear elasticity problems.

thermalmodel = createpde("thermal",ThermalAnalysisType) returns a thermal analysis model for the specified analysis type.

emagmodel = createpde("electromagnetic",ElectromagneticAnalysisType) returns an electromagnetic analysis model for the specified analysis type.

Examples

Create General PDE Model

Create a model for a general linear or nonlinear single (scalar) PDE.

model = createpde

model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Create a PDE model for a system of three equations.

model = createpde(3)

model = 
  PDEModel with properties:

           PDESystemSize: 3
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Create Structural Model

Create a static structural model for solving a solid (3-D) problem.

staticStructural = createpde("structural","static-solid")

staticStructural = 
  StructuralModel with properties:

              AnalysisType: "static-solid"
                  Geometry: []
        MaterialProperties: []
                 BodyLoads: []
        BoundaryConditions: []
      ReferenceTemperature: []
    SuperelementInterfaces: []
                      Mesh: []
             SolverOptions: [1x1 pde.PDESolverOptions]

Create a transient structural model for solving a plane-stress (2-D) problem.

transientStructural = createpde("structural","transient-planestress")

transientStructural = 
  StructuralModel with properties:

              AnalysisType: "transient-planestress"
                  Geometry: []
        MaterialProperties: []
                 BodyLoads: []
        BoundaryConditions: []
             DampingModels: []
         InitialConditions: []
    SuperelementInterfaces: []
                      Mesh: []
             SolverOptions: [1x1 pde.PDESolverOptions]

Create a structural model for modal analysis of a plane-strain (2-D) problem.

modalStructural = createpde("structural","modal-planestrain")

modalStructural = 
  StructuralModel with properties:

              AnalysisType: "modal-planestrain"
                  Geometry: []
        MaterialProperties: []
        BoundaryConditions: []
    SuperelementInterfaces: []
                      Mesh: []
             SolverOptions: [1x1 pde.PDESolverOptions]

Create a structural model for frequency response analysis of an axisymmetric problem. An axisymmetric model simplifies a 3-D problem to a 2-D problem using symmetry around the axis of rotation.

frStructural = createpde("structural","frequency-axisymmetric")

frStructural = 
  StructuralModel with properties:

              AnalysisType: "frequency-axisymmetric"
                  Geometry: []
        MaterialProperties: []
                 BodyLoads: []
        BoundaryConditions: []
             DampingModels: []
    SuperelementInterfaces: []
                      Mesh: []
             SolverOptions: [1x1 pde.PDESolverOptions]

Create Thermal Model

Create a model for steady-state thermal analysis.

thermalmodel = createpde("thermal","steadystate")

thermalmodel = 
  ThermalModel with properties:

               AnalysisType: "steadystate"
                   Geometry: []
         MaterialProperties: []
                HeatSources: []
    StefanBoltzmannConstant: []
         BoundaryConditions: []
          InitialConditions: []
                       Mesh: []
              SolverOptions: [1x1 pde.PDESolverOptions]

Create a model for transient thermal analysis.

thermalmodel = createpde("thermal","transient")

thermalmodel = 
  ThermalModel with properties:

               AnalysisType: "transient"
                   Geometry: []
         MaterialProperties: []
                HeatSources: []
    StefanBoltzmannConstant: []
         BoundaryConditions: []
          InitialConditions: []
                       Mesh: []
              SolverOptions: [1x1 pde.PDESolverOptions]

Create a model for modal thermal analysis.

thermalmodel = createpde("thermal","modal")

thermalmodel = 
  ThermalModel with properties:

               AnalysisType: "modal"
                   Geometry: []
         MaterialProperties: []
                HeatSources: []
    StefanBoltzmannConstant: []
         BoundaryConditions: []
          InitialConditions: []
                       Mesh: []
              SolverOptions: [1x1 pde.PDESolverOptions]

Create a transient thermal model for solving an axisymmetric problem. An axisymmetric model simplifies a 3-D problem to a 2-D problem using symmetry around the axis of rotation.

thermalmodel = createpde("thermal","transient-axisymmetric")

thermalmodel = 
  ThermalModel with properties:

               AnalysisType: "transient-axisymmetric"
                   Geometry: []
         MaterialProperties: []
                HeatSources: []
    StefanBoltzmannConstant: []
         BoundaryConditions: []
          InitialConditions: []
                       Mesh: []
              SolverOptions: [1x1 pde.PDESolverOptions]

Create Electromagnetic Model

Create a model for electrostatic analysis.

emagE = createpde("electromagnetic","electrostatic")

emagE = 
  ElectromagneticModel with properties:

          AnalysisType: "electrostatic"
              Geometry: []
    MaterialProperties: []
               Sources: []
    BoundaryConditions: []
    VacuumPermittivity: []
                  Mesh: []

Create an axisymmetric model for magnetostatic analysis. An axisymmetric model simplifies a 3-D problem to a 2-D problem using symmetry around the axis of rotation.

emagMA = createpde("electromagnetic","magnetostatic-axisymmetric")

emagMA = 
  ElectromagneticModel with properties:

          AnalysisType: "magnetostatic-axisymmetric"
              Geometry: []
    MaterialProperties: []
               Sources: []
    BoundaryConditions: []
    VacuumPermeability: []
                  Mesh: []

Create a model for harmonic analysis.

emagH = createpde("electromagnetic","harmonic")

emagH = 
  ElectromagneticModel with properties:

          AnalysisType: "harmonic"
              Geometry: []
    MaterialProperties: []
               Sources: []
    BoundaryConditions: []
    VacuumPermittivity: []
    VacuumPermeability: []
                  Mesh: []
             FieldType: "electric"

Create a model for DC conduction analysis.

emagDC = createpde("electromagnetic","conduction")

emagDC = 
  ElectromagneticModel with properties:

          AnalysisType: "conduction"
              Geometry: []
    MaterialProperties: []
    BoundaryConditions: []
                  Mesh: []

Input Arguments

N — Number of equations

1 (default) | positive integer

Number of equations, specified as a positive integer. You do not need to specify N for a model where N = 1.

Example: model = createpde

Example: model = createpde(3);

Data Types: double

StructuralAnalysisType — Type of structural analysis

"static-solid" | "static-planestress" | "static-planestrain" | "static-axisymmetric" | "transient-solid" | "transient-planestress" | "transient-planestrain" | "transient-axisymmetric" | "modal-solid" | "modal-planestress" | "modal-planestrain" | "modal-axisymmetric" | "frequency-solid" | "frequency-planestress" | "frequency-planestrain" | "frequency-axisymmetric"

Type of structural analysis, specified as one of the following values.

For static analysis, use these values:

• "static-solid" — Creates a structural model for static analysis of a solid (3-D) problem.

• "static-planestress" — Creates a structural model for static analysis of a plane-stress problem.

• "static-planestrain" — Creates a structural model for static analysis of a plane-strain problem.

• "static-axisymmetric" — Creates an axisymmetric (2-D) structural model for static analysis.

For transient analysis, use these values:

• "transient-solid" — Creates a structural model for transient analysis of a solid (3-D) problem.

• "transient-planestress" — Creates a structural model for transient analysis of a plane-stress problem.

• "transient-planestrain" — Creates a structural model for transient analysis of a plane-strain problem.

• "transient-axisymmetric" — Creates an axisymmetric (2-D) structural model for transient analysis.

For modal analysis, use these values:

• "modal-solid" — Creates a structural model for modal analysis of a solid (3-D) problem.

• "modal-planestress" — Creates a structural model for modal analysis of a plane-stress problem.

• "modal-planestrain" — Creates a structural model for modal analysis of a plane-strain problem.

• "modal-axisymmetric" — Creates an axisymmetric (2-D) structural model for modal analysis.

For frequency response analysis, use these values:

• "frequency-solid" — Creates a structural model for frequency response analysis of a solid (3-D) problem.

• "frequency-planestress" — Creates a structural model for frequency response analysis of a plane-stress problem.

• "frequency-planestrain" — Creates a structural model for frequency response analysis of a plane-strain problem.

• "frequency-axisymmetric" — Creates an axisymmetric (2-D) structural model for frequency response analysis.

For axisymmetric models, the toolbox assumes that the axis of rotation is the vertical axis passing through r = 0.

Example: model = createpde("structural","static-solid")

Data Types: char | string

ThermalAnalysisType — Type of thermal analysis

"steadystate" | "steadystate-axisymmetric" | "transient" | "transient-axisymmetric" | "modal" | "modal-axisymmetric"

Type of thermal analysis, specified as one of these values:

• "steadystate" — Creates a steady-state thermal model. If you do not specify ThermalAnalysisType for a thermal model, createpde creates a steady-state model.

• "steadystate-axisymmetric" — Creates an axisymmetric (2-D) thermal model for steady-state analysis.

• "transient" — Creates a transient thermal model.

• "transient-axisymmetric" — Creates an axisymmetric (2-D) thermal model for transient analysis.

• "modal" — Creates a thermal model for modal analysis. Modal solutions enable you to speed up transient thermal analysis by using the reduced-order modeling (ROM) technique.

• "modal-axisymmetric" creates an axisymmetric (2-D) thermal model for modal analysis.

For axisymmetric models, the toolbox assumes that the axis of rotation is the vertical axis passing through r = 0.

Example: model = createpde("thermal","transient")

Data Types: char | string

ElectromagneticAnalysisType — Type of electromagnetic analysis

"electrostatic" | "magnetostatic" | "harmonic" | "conduction" | "electrostatic-axisymmetric" | "magnetostatic-axisymmetric" | "harmonic-axisymmetric"

Type of electromagnetic analysis, specified as one of these values:

• "electrostatic" — Creates a model for electrostatic analysis.

• "magnetostatic" — Creates a model for magnetostatic analysis.

• "harmonic" creates a model for harmonic electromagnetic analysis.

• "conduction" — Creates a model for DC conduction analysis.

• "electrostatic-axisymmetric" — Creates an axisymmetric (2-D) model for electrostatic analysis.

• "magnetostatic-axisymmetric" — Creates an axisymmetric (2-D) model for magnetostatic analysis.

• "harmonic-axisymmetric" — Creates an axisymmetric (2-D) model for harmonic electromagnetic analysis.

For axisymmetric models, the toolbox assumes that the axis of rotation is the vertical axis passing through r = 0.

Example: model = createpde("electromagnetic","electrostatic")

Data Types: char | string

Output Arguments

model — PDE model

PDEModel object

PDE model, returned as a PDEModel object.

Example: model = createpde(2)

structuralmodel — Structural model

StructuralModel object

Structural model, returned as a StructuralModel object.

Example: structuralmodel = createpde("structural","static-solid")

thermalmodel — Thermal model

ThermalModel object

Thermal model, returned as a ThermalModel object.

Example: thermalmodel = createpde("thermal","transient")

emagmodel — Electromagnetic model

ElectromagneticModel object

Electromagnetic model, returned as an ElectromagneticModel object.

Example: emagmodel = createpde("electromagnetic","magnetostatic")

Version History

Introduced in R2015a

R2021a: Electromagnetic analysis

createpde now can create a model for electromagnetic analysis.

R2020a: Axisymmetric analysis

createpde now can create a model for axisymmetric thermal and structural analyses. Axisymmetric analysis simplifies 3-D structural and thermal problems to 2-D using their symmetry around the axis of rotation.

R2017b: Structural analysis

createpde now can create a model for structural analysis.

R2017a: Thermal analysis

createpde now can create a model for thermal analysis.