Resistance Change by Deformationexamples|products|Murata Software Co., Ltd.

Example3 Resistance Change by Deformation

General

  • A resistance change of the wiring by deformation is analyzed.
     

  • The principle of strain gauge is simulated in this analysis.

  • [Analysis with deformed shape taken into consideration] is used.

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

 

 

Three analysis models are prepared.

 

・Before deformation (electric field analysis)

・Deformed shape (mechanical stress analysis)

・After deformation (electric field analysis)

 

See Analysis with deformed shape taken into account for the details.

 

Analysis Model 1: Before Deformation

Set up analysis before the deformation. The model is named [Before deformation].

Analysis Space

Item

Setting

Analysis Space

3D

Model unit

mm

 

Matrix solver type is iterative method when [Automatic] is selected. But in this example, the direct method is used as the accuracy of the iterative method is low.

Tab

Setting Item

Setting

High-Level Setting

Matrix solver type

Direct method

 

Analysis Condition

Item

Setting

Solver

Electric field analysis [Coulomb]

Analysis Type

Static analysis (resistance)

Options

None

 

Model

A strain gauge is created.

Create a cubic solid body for a base.

Create a geometry for the line shape.

Create a straight line with sheet body and a curve with wire body. The wire body is rotated and stretched in the thickness direction.

Create pads by cubic solid bodies.

Set the potential boundary condition on the top of the solid bodies.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

Base

Base

26/Solid

Pad

010_Ni *

27/Solid

Pad

010_Ni *

28/Solid

Line

010_Ni *

* Available from the material DB

 

The base is excluded from the analysis domain as it is assumed to be an insulator.

Body Attribute Name

Tab

Setting

Base

Analysis Domain

Deselect “For use in electric field analysis”

Boundary Condition

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Setting

V0/Face

Electric

Electric wall

Voltage specified, 1[V]

V1/Face

Electric

Electric wall

Voltage specified, 0[V]

 

Mesh Size Setting

Body Number/Type

Size

0/Solid

0.05

Analysis Model 2: Deformed Shape Calculation

The device created for Analysis Model 1 is placed on a substrate, and the substrate is bent for mechanical stress analysis.

Copy Analysis Model 1 (before deformation) and set up as follows. The model is named [Deformed shape calculation].

See [Copy Analysis Model into Project] for the details.

Analysis Condition

Item

Setting

Solver

Mechanical stress analysis [Galileo]

Analysis Type

Static analysis

Options

None

 

Model

A substrate is created with a cubic solid body and placed under the Analysis Model 1.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

Base

Base

26/Solid

Pad

010_Ni *

27/Solid

Pad

010_Ni *

28/Solid

Line

010_Ni *

Body29/Solid

Board

006_Glass_epoxy *

* Available from the material DB

 

Enter the following value as the Young’s modulus of the Base is not defined.

Material Name

Tab

Setting

Base

Elastic Modulus

Young’s modulus: 5.0×10^9

Boundary Condition

Fixation and displacement are given to bend the substrate.

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Setting

V0/Face

Mechanical

Free

 

V1/Face

Mechanical

Free

 

Fix/Face

Mechanical

Displacement

Select all X/Y/Z components.

UX=0, UY=0, UZ=0

Push/Line

Mechanical

Displacement

Select the Z Component.
UZ = -1 x 10^-3

 

Analysis Model 3: After Deformation

Set up the analysis that takes the deformed shape into account.

Copy Analysis Model 1 (before deformation) and set up as follows. The model is named [After deformation].

See [Copy Analysis Model into Project] for the details.

Analysis Condition

Specify Analysis Model 2 (Deformation shape calculation) on the result import tab.

 

Tab

Setting Item

Setting

Result Import

Import Type

Deformed shape

Specify Results

Specify Analysis Model [Deformed Shape Calculation]

 

Run Mesher/Solver

Run the solver with all analysis models. Calculation of Analysis Model 2 (deformed shape calculation) must be completed before going on to Analysis Model 3 (after deformation).

Results

A contour diagram below shows the magnitude of current density of Analysis Model 1 (before deformation).

Current running through the wiring can be observed.

 

 

To see the results, go to the [Results] tab

 

 

 and click [Table] .

 

Results of Analysis Model 1 (Before deformation) are as follows.

The resistance of R1-2 is 6.854[Ω].

 

 

 

A displacement diagram of Analysis Model 2 (Deformed shape calculation) is shown as below. The contour diagram shows the strain perpendicular to the X axis.

The strain is observed on the surface of the substrate due to the bending by the load.

A diagram below shows a close-up of the wiring area.

It can be observed that the strain on the wiring area is almost the same in magnitude as on the substrate surface.

 

 

The following contour diagram shows the magnitude of current density of Analysis Model 3 (after deformation).

Displacement diagram setting is ON.

The current in the deformation can be observed.

 

Results of Analysis Model 3 (After deformation) are as follows.

The resistance of R1-2 is 6.883[Ω]. It confirms that the resistance is increased due to the deformation.