Home / Examples / Coupled Analysis / Thermal-Stress Analysis [Watt/Galileo] / Example 5: Temperature Dependency of Coefficient of Thermal Expansion

Example 5: Temperature Dependency of Coefficient of Linear Thermal Expansion

General

The model is a cylinder of a material having a temperature-dependent coefficient of linear thermal expansion.
The cylinder is subjected to a thermal load of temperature variation.
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	Setting
Step/Thermal Load *	Reference Temperature	0 [deg]

* The reached temperatures come from the thermal analysis.

Model

A cylindrical solid body is defined. The material is set with temperature-dependent coefficient of linear thermal expansion.
The cylinder's top and bottom faces are set with different temperature by the "temperature" boundary condition.

Body Attributes and Materials

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

Temperature dependency of coefficient of linear thermal expansion is set on the nonlinear table.

Material Name

Tab

Settings

Material_Property_001

Thermal Conductivity

1 [W/m/deg]

Elasticity

Young's Modulus: 1×109 [Pa]

Coefficient of Linear Thermal Expansion

Temperature Dependency: Select Yes

[Temperature-Coefficient of Linear Thermal Expansion] Table *

Temperature [deg]	Coefficient of Linear Thermal Expansion [1/deg]
0	1x10-6
100	10x10-6

* This is not the actual material's property.

Press the [Graph] button in the [Edit Nonlinearity Table] tab.
The following graph will appear. The nonlinearity can be confirmed.

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]
0degree/Face	Thermal	Temperature	0 [deg]

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 top face.

The vectors of the stress are shown below.

The inner area is getting the tensile stress, whereas the outer area is getting the compressive stress.