# StructuralModel

Structural model object

## Description

A `StructuralModel`

object contains
information about a structural analysis problem: the geometry, material properties,
damping parameters, body loads, boundary loads, boundary constraints, superelement
interfaces, initial displacement and velocity, and mesh.

## Creation

To create a `StructuralModel`

object, use `createpde`

and specify `'structural'`

as its first
argument .

## Properties

`AnalysisType`

— 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, returned as one of these values.

Static analysis:

`'static-solid'`

for static structural analysis of a solid (3-D) problem`'static-planestress'`

for static structural analysis of a plane-stress problem`'static-planestrain'`

for static structural analysis of a plane-strain problem`'static-axisymmetric'`

for static structural analysis of an axisymmetric (2-D) problem

Transient analysis:

`'transient-solid'`

for transient structural analysis of a solid (3-D) problem`'transient-planestress'`

for transient structural analysis of a plane-stress problem`'transient-planestrain'`

for transient structural analysis of a plane-strain problem`'transient-axisymmetric'`

for transient structural analysis of an axisymmetric (2-D) problem

Modal analysis:

`'modal-solid'`

for modal analysis of a solid (3-D) problem`'modal-planestress'`

for modal analysis of a plane-stress problem`'modal-planestrain'`

for modal analysis of a plane-strain problem`'modal-axisymmetric'`

for modal analysis of an axisymmetric (2-D) problem

Frequency response analysis:

`'frequency-solid'`

for frequency response analysis of a solid (3-D) problem`'frequency-planestress'`

for frequency response analysis of a plane-stress problem`'frequency-planestrain'`

for frequency response analysis of a plane-strain problem`'frequency-axisymmetric'`

for frequency response analysis of an axisymmetric (2-D) problem

To change a structural analysis type, assign a new type to
`model.AnalysisType`

. Ensure that all other properties
of the model are consistent with the new analysis type. Note that you cannot
change the spatial dimensionality. For example, you can change the analysis
type from `'static-solid'`

to
`'modal-solid'`

, but cannot change it to
`'static-planestress'`

.

**Example: **```
model =
createpde('structural','static-solid')
```

**Data Types: **`char`

`Geometry`

— Geometry description

`AnalyticGeometry`

| `DiscreteGeometry`

Geometry description, returned as `AnalyticGeometry`

for
a 2-D geometry or `DiscreteGeometry`

for a 2-D or 3-D
geometry.

`MaterialProperties`

— Material properties

`StructuralMaterialAssignment`

object containing
material property assignments

Material properties within the domain, returned as a
`StructuralMaterialAssignment`

object containing the
material property assignments. For details, see StructuralMaterialAssignment Properties.

To create the material properties assignments for your structural analysis
model, use the `structuralProperties`

function.

`BodyLoads`

— Loads acting on domain or subdomain

`BodyLoadAssignment`

object containing body load
assignments

Loads acting on the domain or subdomain, returned as a
`BodyLoadAssignment`

object containing body load
assignments. For details, see BodyLoadAssignment Properties.

To create body load assignments for your structural analysis model, use
the `structuralBodyLoad`

function.

`BoundaryConditions`

— Structural loads and boundary conditions

`StructuralBC`

object containing boundary condition
assignments

Structural loads and boundary conditions applied to the geometry, returned
as a `StructuralBC`

object containing the boundary
condition assignments. For details, see StructuralBC Properties.

To specify boundary conditions for your model, use the `structuralBC`

function. To specify boundary loads, use
`structuralBoundaryLoad`

.

`DampingModels`

— Damping model for transient or frequency response analysis

`StructuralDampingAssignment`

object containing damping
assignments

Damping model for transient or frequency response analysis, returned as a
`StructuralDampingAssignment`

object containing damping
assignments. For details, see StructuralDampingAssignment Properties.

To set damping parameters for your structural model, use the `structuralDamping`

function.

`ReferenceTemperature`

— Reference temperature for thermal load

0 (default) | number

Reference temperature for a thermal load, specified as a number. The reference temperature corresponds to state of zero thermal stress of the model. The default value 0 implies that the thermal load is specified in terms of the temperature change and its derivatives.

To specify the reference temperature for a thermal load in your static
structural model, assign the property value directly, for example,
`structuralmodel.ReferenceTemperature = 10`

. To specify
the thermal load itself, use the `structuralBodyLoad`

function.

**Data Types: **`double`

`InitialConditions`

— Initial displacement and velocity

`GeometricStructuralICs`

object | `NodalStructuralICs`

object

Initial displacement and velocity, returned as a
`GeometricStructuralICs`

or
`NodalStructuralICs`

object. For details, see GeometricStructuralICs Properties and NodalStructuralICs Properties.

To set initial conditions for your transient structural model, use the
`structuralIC`

function.

`SuperelementInterfaces`

— Superelement interfaces for component mode synthesis

`StructuralSEIAssignment`

object containing superelement
interfaces assignments

Superelement interfaces for the component mode synthesis, returned as a
`StructuralSEIAssignment`

object containing
superelement interface assignments. For details, see StructuralSEIAssignment Properties.

To specify superelement interfaces for your frequency response structural
model, use the `structuralSEInterface`

function.

`Mesh`

— Mesh for solution

`FEMesh`

object

Mesh for solution, returned as a `FEMesh`

object. For
property details, see FEMesh Properties.

To create the mesh, use the `generateMesh`

function.

`SolverOptions`

— Algorithm options for PDE solvers

`PDESolverOptions`

object

Algorithm options for the PDE solvers, returned as a PDESolverOptions Properties object. The
properties of `PDESolverOptions`

include absolute and
relative tolerances for internal ODE solvers, maximum solver iterations, and
so on.

## Object Functions

`geometryFromEdges` | Create 2-D geometry from decomposed geometry matrix |

`geometryFromMesh` | Create 2-D or 3-D geometry from mesh |

`importGeometry` | Import 2-D or 3-D geometry from STL data |

`structuralBC` | Specify boundary conditions for structural model |

`structuralSEInterface` | Specify structural superelement interface for component mode synthesis |

`structuralBodyLoad` | Specify body load for structural model |

`structuralBoundaryLoad` | Specify boundary loads for structural model |

`structuralIC` | Set initial conditions for a transient structural model |

`structuralProperties` | Assign structural properties of material for structural model |

`solve` | Solve heat transfer, structural analysis, or electromagnetic analysis problem |

`reduce` | Reduce structural or thermal model |

## Examples

### Create and Populate Structural Analysis Model

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

structuralModel = createpde('structural','static-solid')

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

Create and plot the geometry.

```
gm = multicuboid(0.5,0.1,0.1);
structuralModel.Geometry = gm;
pdegplot(structuralModel,'FaceAlpha',0.5)
```

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

structuralProperties(structuralModel,'Cell',1,'YoungsModulus',210E3, ... 'PoissonsRatio',0.3, ... 'MassDensity',2.7E-6)

ans = StructuralMaterialAssignment with properties: RegionType: 'Cell' RegionID: 1 YoungsModulus: 210000 PoissonsRatio: 0.3000 MassDensity: 2.7000e-06 CTE: [] HystereticDamping: []

Specify the gravity load on the rod.

structuralBodyLoad(structuralModel, ... 'GravitationalAcceleration',[0;0;-9.8])

ans = BodyLoadAssignment with properties: RegionType: 'Cell' RegionID: 1 GravitationalAcceleration: [3x1 double] AngularVelocity: [] Temperature: [] TimeStep: [] Label: []

Specify that face 6 is a fixed boundary.

structuralBC(structuralModel,'Face',6,'Constraint','fixed')

ans = StructuralBC with properties: RegionType: 'Face' RegionID: 6 Vectorized: 'off' Boundary Constraints and Enforced Displacements Displacement: [] XDisplacement: [] YDisplacement: [] ZDisplacement: [] Constraint: "fixed" Radius: [] Reference: [] Label: [] Boundary Loads Force: [] SurfaceTraction: [] Pressure: [] TranslationalStiffness: [] Label: []

Specify the surface traction for face 5.

structuralBoundaryLoad(structuralModel, ... 'Face',5, ... 'SurfaceTraction',[0;0;100])

ans = StructuralBC with properties: RegionType: 'Face' RegionID: 5 Vectorized: 'off' Boundary Constraints and Enforced Displacements Displacement: [] XDisplacement: [] YDisplacement: [] ZDisplacement: [] Constraint: [] Radius: [] Reference: [] Label: [] Boundary Loads Force: [] SurfaceTraction: [3x1 double] Pressure: [] TranslationalStiffness: [] Label: []

Generate a mesh.

generateMesh(structuralModel)

ans = FEMesh with properties: Nodes: [3x7800 double] Elements: [10x4857 double] MaxElementSize: 0.0208 MinElementSize: 0.0104 MeshGradation: 1.5000 GeometricOrder: 'quadratic'

View the properties of `structuralModel`

.

structuralModel

structuralModel = StructuralModel with properties: AnalysisType: "static-solid" Geometry: [1x1 DiscreteGeometry] MaterialProperties: [1x1 StructuralMaterialAssignmentRecords] BodyLoads: [1x1 BodyLoadAssignmentRecords] BoundaryConditions: [1x1 StructuralBCRecords] ReferenceTemperature: [] SuperelementInterfaces: [] Mesh: [1x1 FEMesh] SolverOptions: [1x1 pde.PDESolverOptions]

## Version History

**Introduced in R2017b**

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