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Transform method of processing for speckle strain-rate measurements

Description: 
We have developed a highly sensitive method for measuring thermal expansion, mechanical strain, and creep rates. We use the well-known technique of observing laser speckle with a pair of linear array cameras, but we employ a data-processing approach based on a two-dimensional transform of the speckle histories from each camera. This technique can effect large gauge sizes, which are important in the assessment of the spatial statistics of creep. Further, the algorithm provides simultaneous global estimates of the strain rates at both small- and large-scale sizes. This feature may be of value in the investigation of materials with different short- and long-range orders. General advantages of our technique are compact design, modest resolution requirements, insensitivity to slow surface microstructure changes (as seen with oxidation), and insensitivity to zero-mean-noise processes such as turbulence and vibration. Herein we detail the theory of our technique and the results of a number of experiments. Thesetests are intended to demonstrate the performance advantages and limitations of the transform method of processing speckle strain-rate data.
Record Format: 
application/pdf
1994-01-01T08:00:00Z
Subject: 
Expansion (Heat)
Speckle metrology
Thermal stresses -- Measurement
Electrical and Computer Engineering
Type: 
text
Raw Url: 
http://pdxscholar.library.pdx.edu/do/oai/?metadataPrefix=&verb=GetRecord&identifier=oai:pdxscholar.library.pdx.edu:ece_fac-1117
Source: 
Electrical and Computer Engineering Faculty Publications and Presentations
Repository Record Id: 
oai:pdxscholar.library.pdx.edu:ece_fac-1117
SetSpec: 
publication:ece_fac
publication:ece
publication:communities
publication:mcecs
Record Title: 
Transform method of processing for speckle strain-rate measurements
https://pdxscholar.library.pdx.edu/ece_fac/118
https://pdxscholar.library.pdx.edu/context/ece_fac/article/1117/viewcontent/transform_method_of_processing.pdf
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Resource OE Format: