Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4....

24
Department of Mechanical Engineering MEMS1049 Mechatronics Chapter 9 Resistive Sensors 9-3

Transcript of Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4....

Page 1: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

MEMS1049

MechatronicsChapter 9

Resistive Sensors 9-3

Department of Mechanical Engineering

Background Theory For Metal Strain Gauge Resistance R (Ohm Ω) and

resistivity ρ (Ωm)

For Semiconductors The piezoresistive effect describes the changing resistivity of a semiconductor due to applied mechanical stressstrain

Gauge factor G of a piezoresistive device

Axial strain

Stress

ALR ρ=

axial

RRGε∆

=

LL

axial∆

AForce

axial =σ

Department of Mechanical Engineering

Metal foil strain gauge

Strain gauge structure

Department of Mechanical Engineering

Strain gauge configurations

Various Strain Gauge Configurations

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gaugeALR ρ=

wdw

hdh

AdA

whA

+=

=

AdA

LdLd

RdR

ALR

minus+=

minus+=

ρρ

ρ lnlnlnln

LdL

wdw

hdh νminus==

LdL

AdA ν2minus=

( ) ρρεν

νεερρ

dRdR

dR

dR

axial

axialaxial

++=

++=

21

2

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 2: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Background Theory For Metal Strain Gauge Resistance R (Ohm Ω) and

resistivity ρ (Ωm)

For Semiconductors The piezoresistive effect describes the changing resistivity of a semiconductor due to applied mechanical stressstrain

Gauge factor G of a piezoresistive device

Axial strain

Stress

ALR ρ=

axial

RRGε∆

=

LL

axial∆

AForce

axial =σ

Department of Mechanical Engineering

Metal foil strain gauge

Strain gauge structure

Department of Mechanical Engineering

Strain gauge configurations

Various Strain Gauge Configurations

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gaugeALR ρ=

wdw

hdh

AdA

whA

+=

=

AdA

LdLd

RdR

ALR

minus+=

minus+=

ρρ

ρ lnlnlnln

LdL

wdw

hdh νminus==

LdL

AdA ν2minus=

( ) ρρεν

νεερρ

dRdR

dR

dR

axial

axialaxial

++=

++=

21

2

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 3: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Metal foil strain gauge

Strain gauge structure

Department of Mechanical Engineering

Strain gauge configurations

Various Strain Gauge Configurations

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gaugeALR ρ=

wdw

hdh

AdA

whA

+=

=

AdA

LdLd

RdR

ALR

minus+=

minus+=

ρρ

ρ lnlnlnln

LdL

wdw

hdh νminus==

LdL

AdA ν2minus=

( ) ρρεν

νεερρ

dRdR

dR

dR

axial

axialaxial

++=

++=

21

2

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 4: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Strain gauge configurations

Various Strain Gauge Configurations

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gaugeALR ρ=

wdw

hdh

AdA

whA

+=

=

AdA

LdLd

RdR

ALR

minus+=

minus+=

ρρ

ρ lnlnlnln

LdL

wdw

hdh νminus==

LdL

AdA ν2minus=

( ) ρρεν

νεερρ

dRdR

dR

dR

axial

axialaxial

++=

++=

21

2

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 5: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gaugeALR ρ=

wdw

hdh

AdA

whA

+=

=

AdA

LdLd

RdR

ALR

minus+=

minus+=

ρρ

ρ lnlnlnln

LdL

wdw

hdh νminus==

LdL

AdA ν2minus=

( ) ρρεν

νεερρ

dRdR

dR

dR

axial

axialaxial

++=

++=

21

2

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 6: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Gauge Factor

Gauge factor of metal foil strain gauge

( ) ρρεν dRdR axial ++= 21

( )axialaxial

dRdRε

ρρνε

++= 21

F Gauge factor Piezoresistive effect for semiconductors

axial

RdRFε

=

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 7: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Strain Gauge Bridge

Static bridge circuit for strain gauge In the balance state

High impedance VM

The unknown resistor R1

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 8: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Strain gauge bridge circuit

Dynamic unbalanced bridge circuit

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 9: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Leadwire effect in frac14 bridge circuit

If strain gauge located far from the bridge circuit

Lead wire resistance R΄ can be effect by temperature

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 10: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Temperature compensation

Temperature change can cause significant change in resistance Using a dummy gauge

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 11: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Uniaxial stress

xx Eεσ =

AP

x =σ

xAEP ε=

Precision Strain Gages -1-Axis General Purpose

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 12: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Review Stress-strain

Hookrsquos Lawhellip

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 13: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 14: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Review Planar stress

Principal stresses

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 15: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 16: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial stress

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 17: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Biaxial strain gauges for measuring axial strain 090deg gauge pattern

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 18: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

General state of planar stress on the surface of a component

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 19: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Common rosette configurations

For rectangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 20: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

Three -Element Strain Gage Rosettes Pre-Wired

Rectangular strain gage rosette

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 21: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

For equiangular rosette configuration

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 22: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Stress measurement with strain gauge

For T rosette configuration

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 23: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors
Page 24: Mechanics of Materials - University of Pittsburghqiw4/Academic/MEMS1082/Chapter9-3.pdf · 2011. 4. 4. · Chapter 9 . Resistive Sensors 9-3. Department of Mechanical Engineering.

Department of Mechanical Engineering

Piezoresistive strain sensors

( )axialaxial

dRdRε

ρρνε

++= 21

The change in resistivity may be related as follows

bull where i and j take values from 1 to 6 denoting the parameters in the corresponding strain direction and γ is the piezo-resistive coefficient Material such as single crystal silicon has a cubic crystal structure of which γ can be described using three constants γ11 γ12 and γ44

  • MEMS1049
  • Slide Number 2
  • Metal foil strain gauge
  • Strain gauge configurations
  • Gauge Factor
  • Gauge Factor
  • Strain Gauge Bridge
  • Strain gauge bridge circuit
  • Leadwire effect in frac14 bridge circuit
  • Temperature compensation
  • Stress measurement with strain gauge
  • Review Stress-strain
  • Review Planar stress
  • Review Planar stress
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Stress measurement with strain gauge
  • Piezoresistive strain sensors
  • Piezoresistive strain sensors