OptiStruct for Linear Analysis (6) Thermomechanical Analysis

1. Thermomechanical Analysis Setup

In this lesson we will discuss thermomechanical analysis and how to set up an analysis using OptiStruct and HyperWorks.  In general, the temperature field is not known, but calculated with a thermal analysis.  This can then be referred by a structural model to perform a coupled thermal/structural analysis.  Watch the video below to learn more.

 

Thermal Bending Analysis of a Beam

Forces or moments are not the only load that can cause bodies to expand or contract, but temperature changes can as well.

In general, the temperature field is not known, but calculated with a thermal analysis.  It can then be referred to by a structural model to perform a coupled thermal/structural analysis.

 

OptiStruct can perform the following thermal analysis types:

1. Linear Steady-State Heat Transfer Analysis
2. Linear Transient Heat Transfer Analysis
3. Nonlinear Transient Heat Transfer Analysis (Beta)
4. Nonlinear Steady-State Heat Transfer Analysis
5. One-Step Transient Thermal Stress Analysis
6. Contact-Based Thermal Analysis

 

Thermomechanical Solver Keywords

1. TEMP

The TEMP card defines temperature at grid points or a SET of grid points for determination of thermal loading and stress recovery.  Access this card from: Solver Browser > Bulk Data > Static Loads

Key Parameters:

G/GSETID: Number of implicit load sub-increments

T: Defined Temperature

Tip: Temperature sets may be selected for use in a subcase by the TEMPERATURE Subcase Information Entry.

2. MATT1

The MATT1 card defines temperature-dependent material properties on MAT1 entry fields via TABLEMi or TABLEG entry.  Access this card from: Solver Browser > Bulk Data > Materials.

Key Parameters:

T(E) - Young's modulus. 

T(G) - shear modulus. 

(NU) - Poisson's ratio. 

T(RHO) - mass density. 

T(A) - thermal expansion coefficient.

T(GE) - damping coefficient. 

T(ST) - tension stress limit. 

T(SC) - compression limit.

T(SS) - shear limit.

3. TABLEG

The TABLEG card specifies a general tabular function for use in supported reference entries.  To access this card, select Solver Browser > Bulk Data > Frequency Response Loads.

Key Parameters:

Curve Type: Specifies the type of model associated with the curve (FE/MBD)

Card Image: Sets the card image associated with the curve data

TYPE: Specifies the linear or logarithmic interpolation for the x- and y-axe

XTYPE: Sets interpretation of the column data to specify either x-values first or y-values first

FLAT: Sets extrapolation type outside of curve x-bounds, either flat (last data point) or linear

 

Thermomechanical Analysis Workflow

 

2. Exercise – Thermal Bending Analysis of a Beam

In this exercise we will start by loading a meshed beam model in HyperWorks.  We will create thermal properties and loads in the model and then create a thermal loadstep and run the analysis in Compute Console.  Finally, will analyze the results using the HyperView client.

Watch the video below to view a demonstration of the exercise.  Then download the PDF and model files to do the exercise yourself!

Files:

• ex2d.pdf
• 2D.zip

 

Next: OptiStruct for Linear Analysis (7) Advanced Topics