Static and Dynamic Strain Measurement at Ambient and Elevated Temperatures Using an Extrinsic Fabry–Perot Interferometer (EFPI) Optical Strain Sensor

2015 ◽  
pp. 147-165
Author(s):  
James Sebastian ◽  
William Boles ◽  
James Taylor
Keyword(s):  
Strain Measurement ◽  
Elevated Temperatures ◽  
Strain Sensor ◽  
Dynamic Strain ◽  
Fabry Perot ◽  
Optical Strain

Measurement of dynamic and static strain in small specimens at elevated temperatures

1974 ◽  
Vol 9 (2) ◽  
pp. 130-134
Author(s):  
G Sumner
Keyword(s):  
Strain Measurement ◽  
Elevated Temperatures ◽  
Low Frequency ◽  
Displacement Transducer ◽  
Gauge Length ◽  
Reference Points ◽  
Dynamic Strain ◽  
Optical Displacement ◽  
Creep Fatigue ◽  
Displacement Transducers

A method of strain measurement in small specimens is described which involves measurement of strain in terms of the net displacement of reference points within the specimen ends rather than on the gauge length. The reference points are the bottoms of axial holes drilled into the specimen heads. The method has been developed for high-frequency dynamic-strain measurement using a novel electro-optical displacement transducer and for low-frequency creep-fatigue work using conventional displacement transducers.

A Wireless Strain Sensor Using Frequency Modulation Technique

2009 ◽  
Author(s):  
Hwan-Sik Yoon ◽  
Sanket K. Khedkar
Keyword(s):  
Frequency Modulation ◽  
Strain Gauge ◽  
Strain Measurement ◽  
Measurement Data ◽  
Strain Sensor ◽  
Vibration Measurement ◽  
Dynamic Strain ◽  
Turbine Engine ◽  
Cantilevered Beam ◽  
Remote Station

A compact wireless strain sensor using a Frequency Modulation (FM) technique is proposed. The sensor employs a conventional resistive strain gauge such that the resistance changes as the measured structure is mechanically strained. When the strain gauge is connected to a frequency modulation circuit, the change in the resistance appears as a frequency shift in the output signal that is transmitted wirelessly to a remote station. The received signal is then demodulated and the buried strain measurement data can be retrieved. Using this technique, a dynamic strain measurement is possible without any wire connection between the sensing point and the measurement equipment. This type of sensors have numerous applications in the strain or vibration measurement of moving or rotating structures such as fans on a turbine engine. The proposed concept of the wireless strain sensor is experimentally demonstrated by measuring vibration of a cantilevered beam with a wired transmission of the measurement data from the transmitter to the receiver.

scholarly journals Highly Stretchable Miniature Strain Sensor for Large Dynamic Strain Measurement

2017 ◽  
Vol 1 (3) ◽  
pp. 1-4 ◽  
Author(s):  
Shulong Yao ◽  
Xu Nie ◽  
Xun Yu ◽  
Bo Song ◽  
Jill Blecke
Keyword(s):  
Strain Measurement ◽  
Strain Sensor ◽  
Dynamic Strain ◽  
Highly Stretchable

scholarly journals Development of a fiber optic torque sensor and a single channel, high precision optical strain measurement platform

2021 ◽  
Author(s):  
Nicholas Burgwin
Keyword(s):  
Strain Measurement ◽  
Fiber Optic ◽  
Single Channel ◽  
Optical Measurement ◽  
Spectral Width ◽  
Fiber Optic Sensor ◽  
Torque Sensor ◽  
Interference Immunity ◽  
Fabry Perot ◽  
Optical Strain

Fiber optic sensors based on Fiber Bragg Grating (FBG) technology have been successfully adopted for sensor measurements for almost two decades. The advantages offered by FBG sensors, such as Electro-Magnetic Interference immunity and inherent intrinsic safety, provide motivation for the development of a commercial measurement platform. With the development of an FBG Fabry-Perot cavity, a sensor with sub-picometer spectral width allows for a factor of 1000 times improvement in strain measurement. This thesis presents the development of a highly-accurate optical measurement platform based on the FBG Fabry-Perot cavity and Pound-Drever-Hall (PDH) laser locking technique that is demonstrated through the development of an optical torque sensor. With the fiber optic sensor designed as per the PDH requirements, the platform achieved a measurement accuracy of +/-0.015% of the full-scale torque value of 188N∙m. With the platform at ~$2,000, a successful demonstration of the platform and a fiber optic torque sensor is presented.

scholarly journals Development of a fiber optic torque sensor and a single channel, high precision optical strain measurement platform

2021 ◽  
Author(s):  
Nicholas Burgwin
Keyword(s):  
Strain Measurement ◽  
Fiber Optic ◽  
Single Channel ◽  
Optical Measurement ◽  
Spectral Width ◽  
Fiber Optic Sensor ◽  
Torque Sensor ◽  
Interference Immunity ◽  
Fabry Perot ◽  
Optical Strain

Fiber optic sensors based on Fiber Bragg Grating (FBG) technology have been successfully adopted for sensor measurements for almost two decades. The advantages offered by FBG sensors, such as Electro-Magnetic Interference immunity and inherent intrinsic safety, provide motivation for the development of a commercial measurement platform. With the development of an FBG Fabry-Perot cavity, a sensor with sub-picometer spectral width allows for a factor of 1000 times improvement in strain measurement. This thesis presents the development of a highly-accurate optical measurement platform based on the FBG Fabry-Perot cavity and Pound-Drever-Hall (PDH) laser locking technique that is demonstrated through the development of an optical torque sensor. With the fiber optic sensor designed as per the PDH requirements, the platform achieved a measurement accuracy of +/-0.015% of the full-scale torque value of 188N∙m. With the platform at ~$2,000, a successful demonstration of the platform and a fiber optic torque sensor is presented.

An investigation of photoresists for use in optical strain analysis

1970 ◽  
Vol 5 (3) ◽  
pp. 162-168 ◽  
Author(s):  
A Luxmoore ◽  
R Hermann
Keyword(s):  
Strain Measurement ◽  
Strain Analysis ◽  
Surface Strain ◽  
High Contrast ◽  
Moire Method ◽  
Optical Strain

Some commercial photoresists have been examined to assess their suitability for use with the moiré method of surface-strain measurement. As most of these materials do not produce a pattern of high contrast directly, some etching and plating procedures are also described. Combined with correct illumination, these processes will produce grids of sufficient contrast for most applications.

Monitoring High Temperature Steam Pipes Using Optical Strain Measurement Techniques

2006 ◽  
Vol 5-6 ◽  
pp. 145-152 ◽  
Author(s):  
Andrew Morris ◽  
John P. Dear ◽  
Miltiadis Kourmpetis
Keyword(s):  
Wind Turbine ◽  
Strain Measurement ◽  
Measurement Techniques ◽  
Turbine Blades ◽  
Monitoring Methods ◽  
Wind Turbine Blades ◽  
Optical Strain Measurement ◽  
Optical Strain ◽  
High Temperature Steam ◽  
Steam Pipes

Optical strain measurement techniques have been extensively developed in recent years in order to cope in various environments. Power stations and wind turbine blades can provide challenging environments for the use of a measurement technique. There are, however, many installation problems to be overcome. For example, there is the need to have regard for the hostile environment in steam generating plant and the demanding conditions to which wind turbine blades are subjected. Ideally the outputs from individual sensors would be used for continuous remote monitoring. However, measurements can also be useful each time the plant is shut down during a plant outage; which would be used to complement data from existing proven rugged monitoring methods. This paper addresses the monitoring of pressurized steam pipes as to their micro-strain growth related to time in service. This paper presents the progress made in the developing of a ruggedised digital speckle ‘sensor’ and associated image capture system. The effect of subsurface defects in the strain distribution is examined.

Sign in / Sign up

Export Citation Format

Share Document