# evaluateStress

Evaluate stress for dynamic structural analysis problem

## Syntax

``nodalStress = evaluateStress(structuralresults)``

## Description

example

````nodalStress = evaluateStress(structuralresults)` evaluates stress at nodal locations for all time- or frequency-steps.```

## Examples

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Evaluate the stress in a beam under a harmonic excitation.

Create a transient dynamic model for a 3-D problem.

`structuralmodel = createpde('structural','transient-solid');`

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

```gm = multicuboid(0.06,0.005,0.01); structuralmodel.Geometry = gm; pdegplot(structuralmodel,'FaceLabels','on','FaceAlpha',0.5) view(50,20)``` Specify Young's modulus, Poisson's ratio, and the mass density of the material.

```structuralProperties(structuralmodel,'YoungsModulus',210E9, ... 'PoissonsRatio',0.3, ... 'MassDensity',7800);```

Fix one end of the beam.

`structuralBC(structuralmodel,'Face',5,'Constraint','fixed');`

Apply a sinusoidal displacement along the y-direction on the end opposite the fixed end of the beam.

```structuralBC(structuralmodel,'Face',3, ... 'YDisplacement',1E-4, ... 'Frequency',50);```

Generate a mesh.

`generateMesh(structuralmodel,'Hmax',0.01);`

Specify the zero initial displacement and velocity.

`structuralIC(structuralmodel,'Displacement',[0,0,0],'Velocity',[0,0,0]);`

Solve the model.

```tlist = 0:0.002:0.2; structuralresults = solve(structuralmodel,tlist);```

Evaluate stress in the beam.

`stress = evaluateStress(structuralresults);`

Plot the normal stress along `x`-direction for the last time-step.

```figure pdeplot3D(structuralmodel,'ColorMapData',stress.sxx(:,end)) title('x-Direction Normal Stress in the Beam of the Last Time-Step')``` ## Input Arguments

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Solution of a dynamic structural analysis problem, specified as a `TransientStructuralResults` or `FrequencyStructuralResults` object. Create `structuralresults` by using the `solve` function.

Example: ```structuralresults = solve(structuralmodel,tlist)```

## Output Arguments

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Stress at the nodes, returned as an `FEStruct` object with the properties representing the components of a stress tensor at nodal locations. Properties of an `FEStruct` object are read-only.

## Version History

Introduced in R2018a