Deformation due to the Temperature Gradient #2 – Multiple Materialsexamples|products|Murata Software Co., Ltd.

Example2 Deformation due to the Temperature Gradient #2 – Multiple Materials

General

  • A heating chip is mounted on a substrate. The temperature gradient caused by the heating chip is calculated by thermal analysis [Watt]. This is the same as Exercise 7 of thermal analysis.

     

  • The temperature gradient caused by the heating chip is calculated by thermal analysis [Watt].
    The result is forwarded to mechanical stress analysis [Galileo] as a thermal load.
     

  • The deformation, the displacement and the mechanical stress are solved.
     

  • Unless specified in the list below, the default conditions will be applied.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

Select Thermal analysis and Mechanical stress analysis.

Item

Settings

Solvers

Thermal analysis [Watt]
Mechanical stress analysis [Galileo]

Thermal-Analysis Type

Steady-State Analysis

Options

N/A *

* “Thermal Load” is selected by default for the thermal load-mechanical stress coupled analysis.

 

The Step/Thermal Load tab is set as follows.

Tab

Setting Item

Settings

Step/Thermal Load *

Reference temperature

25[deg]

* The reached temperatures come from the thermal analysis.

Model

The same as Exercise 7 of thermal analysis.

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

VOL1

006_Glass_epoxy *

1/Solid

VOL2

001_Alumina *

* Available from the Material DB

Boundary Conditions

The heat transfer coefficients for the forced convection are calculated as follows. See [Heat Transfer/Ambient Radiation] for more information.

 

h = 3.86 x (V/L)0.5xC [W/m2/deg]

 

where

Air flow V=1[m/s]

On the top and bottom faces of VOL1: Characteristic length L=0.05, C=1 -> h=17.26
Top face of the heat source (VOL2): Characteristic length L=0.02, L’=0.015, C=1 * -> h=27.3

 

*

The thickness (d) of the speed boundary layer at the edges of the heat source is calculated as follows

 

d=0.0182x(L’/V)0.5= 2.3[mm]

 

This is close enough to the thickness of heat source, so we set C=1.

 

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

BC1/Face

Thermal

Heat Transfer/Ambient Radiation

Heat transfer coefficient: 17.26 [W/m2/deg]

Ambient temperature: 25[deg]

BC2/Face

Thermal

Heat Transfer/Ambient Radiation

Heat transfer coefficient: 27.3 [W/m2/deg]

Ambient temperature: 25[deg]

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

Results

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

 

The next figure shows the vectors of displacement as a result of Galileo following Watt.

The temperature gradient causes the deformation.