Engineering Commons^™

Transform Method Of Processing For Speckle Strain-Rate Measurements, Donald D. Duncan, Sean J. Kirkpatrick, F. Fausten Mark, Lawrence W. Hunter

Electrical and Computer Engineering Faculty Publications and Presentations

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- …