structuralProperties

Assign structural properties of material for structural model

Syntax

structuralProperties(structuralmodel,"YoungsModulus",YMval,"PoissonsRatio",PRval)

structuralProperties(___,"MassDensity",MDval)

structuralProperties(___,"CTE",CTEval)

structuralProperties(___,"HystereticDamping",g)

structuralProperties(___,RegionType,RegionID)

mtl = structuralProperties(___)

Description

structuralProperties(structuralmodel,"YoungsModulus",YMval,"PoissonsRatio",PRval) assigns Young's modulus and Poisson's ratio for the entire geometry. Use this syntax if your model is static and does not account for gravitational and thermal effects.

Tip

A structural model supports only homogeneous isotropic materials. Therefore, all material properties must be numeric scalars.

structuralProperties(___,"MassDensity",MDval) assigns the mass density of the material for the entire geometry, and can include any of the arguments used in the previous syntax. Specify the mass density of the material if your model is transient or modal, or if it accounts for gravitational effects.

structuralProperties(___,"CTE",CTEval) assigns the coefficient of thermal expansion for a thermal stress analysis. Use this syntax if your model is static and accounts for thermal effects.

structuralProperties(___,"HystereticDamping",g) assigns the hysteretic damping parameter that models damping forces counteracting velocity but independent of frequency. Use this syntax for direct and modal frequency response analyses.

structuralProperties(___,RegionType,RegionID) assigns material properties for the specified geometry region.

mtl = structuralProperties(___) returns the material properties object.

Examples

Structural Material Properties for Static Model Accounting for Gravity

Create a structural model.

structuralModel = createpde("structural","static-solid");

Import and plot the geometry.

importGeometry(structuralModel,"BracketWithHole.stl");
pdegplot(structuralModel,"FaceAlpha",0.5)

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

structuralProperties(structuralModel,"YoungsModulus",200e9, ...
                                     "PoissonsRatio",0.3, ...
                                     "MassDensity",7800)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 1
        YoungsModulus: 2.0000e+11
        PoissonsRatio: 0.3000
          MassDensity: 7800
                  CTE: []
    HystereticDamping: []

Structural Material Properties for Modal Analysis

Create a structural model for modal analysis.

structuralModel = createpde("structural","modal-solid");

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,"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: []

Structural Material Properties for Thermal Stress Analysis

Specify the coefficients of thermal expansion for a bimetallic cantilever beam. The bottom layer is steel. The top layer is copper.

Create a static structural model.

structuralmodel = createpde("structural","static-solid");

Create and plot the geometry.

gm = multicuboid(0.5,0.04,[0.03,0.03],"Zoffset",[0,0.03]);
structuralmodel.Geometry = gm;
pdegplot(structuralmodel,"CellLabels","on")

Specify Young's modulus, Poisson's ratio, and the coefficient of thermal expansion for the bottom cell C1.

structuralProperties(structuralmodel,"Cell",1, ...
                                     "YoungsModulus",210e9, ...
                                     "PoissonsRatio",0.28, ...
                                     "CTE",1.3e-5)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 1
        YoungsModulus: 2.1000e+11
        PoissonsRatio: 0.2800
          MassDensity: []
                  CTE: 1.3000e-05
    HystereticDamping: []

Specify Young's modulus, Poisson's ratio, and the coefficient of thermal expansion for the top cell C2.

structuralProperties(structuralmodel,"Cell",2, ...
                                     "YoungsModulus",110e9, ...
                                     "PoissonsRatio",0.37, ...
                                     "CTE",2.4e-5)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 2
        YoungsModulus: 1.1000e+11
        PoissonsRatio: 0.3700
          MassDensity: []
                  CTE: 2.4000e-05
    HystereticDamping: []

Hysteretic Damping

Create a frequency response analysis model for a 3-D problem.

structuralmodel = createpde("structural","frequency-solid");

Create nested cylinders to model a bimetallic cable.

gm = multicylinder([0.01,0.015],0.05);

Assign the geometry to the structural model and plot the geometry.

structuralmodel.Geometry = gm;
pdegplot(structuralmodel,"CellLabels","on","FaceAlpha",0.4)

Specify Young's modulus, Poisson's ratio, mass density, and hysteretic damping for both cylinders.

structuralProperties(structuralmodel,"YoungsModulus",110E9, ...
                                     "PoissonsRatio",0.28, ...
                                     "MassDensity",7800, ...
                                     "HystereticDamping",0.2, ...
                                     "Cell",1)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 1
        YoungsModulus: 1.1000e+11
        PoissonsRatio: 0.2800
          MassDensity: 7800
                  CTE: []
    HystereticDamping: 0.2000

structuralProperties(structuralmodel,"YoungsModulus",210E9, ...
                                     "PoissonsRatio",0.3, ...
                                     "MassDensity",7800, ...
                                     "HystereticDamping",0.1, ...
                                     "Cell",2)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 2
        YoungsModulus: 2.1000e+11
        PoissonsRatio: 0.3000
          MassDensity: 7800
                  CTE: []
    HystereticDamping: 0.1000

Structural Material Properties for Each Geometric Region

Create a structural model.

structuralModel = createpde("structural","static-solid");

Create nested cylinders to model a bimetallic cable.

gm = multicylinder([0.01,0.015],0.05);

Assign the geometry to the structural model and plot the geometry.

structuralModel.Geometry = gm;
pdegplot(structuralModel,"CellLabels","on","FaceAlpha",0.4)

Specify Young's modulus and Poisson's ratio for each metal.

structuralProperties(structuralModel,"Cell",1,"YoungsModulus",110E9, ...
                                              "PoissonsRatio",0.28)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 1
        YoungsModulus: 1.1000e+11
        PoissonsRatio: 0.2800
          MassDensity: []
                  CTE: []
    HystereticDamping: []

structuralProperties(structuralModel,"Cell",2,"YoungsModulus",210E9, ...
                                              "PoissonsRatio",0.3)

ans = 
  StructuralMaterialAssignment with properties:

           RegionType: 'Cell'
             RegionID: 2
        YoungsModulus: 2.1000e+11
        PoissonsRatio: 0.3000
          MassDensity: []
                  CTE: []
    HystereticDamping: []

Input Arguments

structuralmodel — Structural model

StructuralModel object

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")

YMval — Young's modulus

positive number

Young's modulus of the material, specified as a positive number.

Example: structuralProperties(structuralmodel,"YoungsModulus",210e3,"PoissonsRatio",0.3)

Data Types: double

PRval — Poisson's ratio

number greater than 0 and less than 0.5

Poisson's ratio of the material, specified as a number greater than 0 and less than 0.5.

Example: structuralProperties(structuralmodel,"YoungsModulus",210e3,"PoissonsRatio",0.3)

Data Types: double

MDval — Mass density

positive number

Mass density of the material, specified as a positive number. This argument is required for transient and modal models. MDval is also required when modeling gravitational effects.

Example: structuralProperties(structuralmodel,"YoungsModulus",210e3,"PoissonsRatio",0.3,"MassDensity",11.7e-6)

Data Types: double

CTEval — Coefficient of thermal expansion

real number

Coefficient of thermal expansion, specified as a real number. This argument is required for thermal stress analysis. Thermal stress analysis requires the structural model to be static.

Example: structuralProperties(structuralmodel,"YoungsModulus",210e3,"PoissonsRatio",0.3,"MassDensity",2.7e-6,"CTE",11.7e-6)

Data Types: double

g — Hysteretic damping

nonnegative number

Hysteretic damping, specified as a nonnegative number. This type of damping is also called structural damping.

Example: structuralProperties(structuralmodel,"YoungsModulus",210E9,"PoissonsRatio",0.3,"MassDensity",7800,"HystereticDamping",0.1)

Data Types: double

RegionType — Geometric region type

"Face" for a 2-D model | "Cell" for a 3-D model

Geometric region type, specified as "Face" for a 2-D model or "Cell" for a 3-D model.

Example: structuralProperties(structuralmodel,"Cell",1,"YoungsModulus",110E9,"PoissonsRatio",0.3)

Data Types: char | string

RegionID — Cell or face ID

vector of positive integers

Cell or face ID, specified as a vector of positive integers. Find the region IDs using pdegplot with the "CellLabels" (3-D) or "FaceLabels" (2-D) value set to "on".

Example: structuralProperties(structuralmodel,"Cell",1:3,"YoungsModulus",110E9,"PoissonsRatio",0.3)

Data Types: double

Output Arguments

mtl — Handle to material properties

StructuralMaterialAssignment object

Handle to material properties, returned as a StructuralMaterialAssignment object. See StructuralMaterialAssignment Properties.

mtl associates the material properties with the geometric region.

Version History

Introduced in R2017b

R2022a: Hysteretic damping

You can now specify hysteretic damping of a material for direct and modal frequency response models.

R2018b: Coefficient of thermal expansion

You can now specify a coefficient of thermal expansion.