Optical Strain Gages for Use at Elevated Temperatures

2009 ◽  
pp. 51-51-6
Author(s):  
H. K. Howerton
Keyword(s):  
Elevated Temperatures ◽  
Strain Gages ◽  
Optical Strain

Compression, Bend, and Tension Studies on Forged Al67Ti25Cr8 and Al66Ti25Mn9 L12 Compounds

1990 ◽  
Vol 213 ◽  
Author(s):  
K.S. Kumar ◽  
S. A. Brown ◽  
J.D. Whittenberger
Keyword(s):  
Elevated Temperatures ◽  
Gradual Transition ◽  
Strain Gages ◽  
Strain Measurements ◽  
Transgranular Cleavage ◽  
Point Bend ◽  
Temperature Scanning ◽  
Increasing Temperature ◽  
Strength And Ductility ◽  
Scanning Electron

ABSTRACTCast, homogenized, and isothermally forged aluminum-rich L12 compounds Al87Ti25Cr8 and Al66Ti25Mn9 were tested in compression as a function of temperature and as a function of strain rate at elevated temperatures (1000K and 1100K). Three-point bend specimens were tested as a function of temperature in the range 300K to 873K. Strain gages glued on the tensile side of the ambient and 473K specimens enabled direct strain measurements. A number of “buttonhead” tensile specimens were electro-discharge machined, fine polished, and tested between ambient and 1073K for yield strength and ductility as a function of temperature. Scanning electron microscope (SEM) examination of fracture surfaces from both the bend and tensile specimens revealed a gradual transition from transgranular cleavage to intergranular failure with increasing temperature.

scholarly journals Evaluation of resistance strain gages at elevated temperatures :

1961 ◽  
Author(s):  
R L Bloss ◽  
J T Trumbo ◽  
C H Melton ◽  
J S Steel
Keyword(s):  
Elevated Temperatures ◽  
Resistance Strain ◽  
Strain Gages

Use of Fiber Optic Sensors for Monitoring Crack Growth in Fatigue and Corrosion-Fatigue Tests

2008 ◽  
Vol 38 ◽  
pp. 155-160 ◽  
Author(s):  
Andrea Brotzu ◽  
F. Felli ◽  
A. Paolozzi ◽  
L. Caputo ◽  
F. Passeggio ◽  
...  
Keyword(s):  
Fiber Optic Sensors ◽  
Fatigue Tests ◽  
Strain Sensors ◽  
Strain Gages ◽  
Fbg Sensors ◽  
Optical Strain ◽  
Fibre Bragg Gratings ◽  
Almost All ◽  
Corrosive Environments ◽  
Through Hole

Fibre Bragg Gratings (FBGs) are optical strain gages manufactured directly inside the fiber core. They provide several advantages with respect to conventional strain gages. In particular it is possible to put several FBGs along the same fibre (multiplexing), they are immune to corrosive environments and to electromagnetic interferences. They can be embedded in almost all types of materials and are very useful in Structural Health Monitoring. An innovative approach for testing specimens in this area is reported in this work. An aluminium alloy 2024-T3 CT specimen has been manufactured with one small feed-through hole and a superficial groove. Two FBG sensors, multiplexed on the same fibre, have been glued one inside the hole and one inside the groove. Fatigue test has been carried out monitoring the crack length both with standard measure system and with the FBG strain sensors placed in front of the crack tip.

scholarly journals Evaluation of resistance strain gages at elevated temperatures :

1961 ◽  
Author(s):  
R L Bloss ◽  
J T Trumbo ◽  
C H Melton ◽  
J S Steel
Keyword(s):  
Elevated Temperatures ◽  
Resistance Strain ◽  
Strain Gages

Characteristics of a Reactively Sputtered Indium Tin Oxide Thin Film Strain Gage for Use at Elevated Temperatures

1995 ◽  
Vol 403 ◽  
Author(s):  
Otto J. Gregory ◽  
Stephen E. Dyer ◽  
Paul S. Amons ◽  
Arnout Bruins SLOT
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Sensors ◽  
Dynamic Strain ◽  
Strain Gages ◽  
Ito Thin Films ◽  
Ito Films

AbstractStrain sensors based on thin films of indium tin oxide (ITO) have been developed for a variety of applications, where the measurement of both static and dynamic strain are required at elevated temperatures. ITO thin films were prepared by rf reactive sputtering in Ar:02 mixtures from high density, electrically conductive targets having a nominal composition of 90% In203 and 10% Sn02. The resulting ITO films exhibited room temperature resistivities between 2x10−2 and 2x102 ω cm, an optical bandgap of 3.5 ev and tested “n” type by hot probe. These same films exhibited large negative gage factors (G=δρ/ ρδε) when tested at room temperature and a relatively low temperature coefficient of resistance when tested at elevated temperature in air. Specifically, gage factors approaching -100 with little hysteresis were observed for strains up to 700 μin/in and TCR's as low as 195 ppm/°C have been measured for the sputtered ITO films. In addition, these films were electrically stable and readily formed ohmic contacts with platinum at temperatures up to 1180°C. In this paper, we report on the electrical properties and piezoresistive properties of ITO based strain gages at temperatures up to 1180°C. Prospects of using ITO thin films as the active strain elements in high temperature strain gages and the characteristics of strain sensors based on ITO are discussed.

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