Home / Examples / Coupled Analysis / Thermal-Stress Analysis [Watt/Galileo] / Example 6: Temperature Dependency of Young's Modulus

Example 6: Temperature Dependency of Young's Modulus

General

The model is a bar of the material having a temperature-dependent Young's modulus.
The bar is subjected to a thermal load to make an uneven deformation.
The deformation, the displacement distribution, and the stress distribution are solved.
Unless specified in the list below, the default conditions will be applied.

Results will vary depending on Femtet version and the PC environment.

Analysis Space

Item	Settings
Analysis Space	3D
Model Unit	mm

Analysis Conditions

Select Thermal analysis and Stress analysis.

Item	Settings
Solver	Thermal Analysis [Watt] Stress Analysis [Galileo]
Thermal-Analysis Type	Steady-state Analysis
Options	N/A *

* [Thermal Load] is selected by default for the thermal-stress coupled analysis.

The Step/Thermal Load tab is set as follows.

Tab	Setting Item	Settings
Step/Thermal Load *	Reference Temperature	0 [deg]

* The reached temperatures come from the thermal analysis.

Model

A rectangular rod is defined. The material is set with temperature-dependent coefficient of expansion.
The rod's end faces are set with different temperature and displacement by [temperature] and [displacement] boundary conditions.

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
0/Solid	Body_Attribute_001	Material_Property_001

Temperature dependency of Young's modulus is set on the nonlinearity table.

Material Name

Tab

Settings

ElasticMaterial

Elasticity

Material Type: Elastic/Isotropic

Temperature Dependency: Yes

[Temperature-Isotropic elasticity] Table *

Temperature [deg]	Young's Modulus [Pa]	Poisson's Ratio.
0	1x109	0.3
100	0.1x109	0.3

* This is not the actual material's property.

Thermal Conductivity

1 [W/m/deg]

Press the Graph button. The following graph will appear.

Boundary Conditions

Thermal analysis is performed based on the boundary conditions below. The resulting temperature distribution is forwarded to stress analysis.

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Settings
100degree/Face	Thermal	Temperature	100 [deg]
100degree/Face	Mechanical	Displacement	Select UY UY=0 [m]
0degree/Face	Thermal	Temperature	0 [deg]
0degree/Face	Mechanical	Displacement	Select UY Uy=0.1x10-3 [m]

Results

The temperature distribution as a result of Watt is shown below.

The vectors of the strain are shown below.

The strain is greater towards the rod's right end.

The vectors of the stress are shown below.

The tensile stress is exhibited in the y direction.