Stabilized and accelerated speckle strain gauge

Ichirou Yamaguchi; Tamiki Takemori; Koichi Kobayashi

doi:10.1117/12.61043

1 March 1993 Stabilized and accelerated speckle strain gauge

Ichirou Yamaguchi, Tamiki Takemori, Koichi Kobayashi

Author Affiliations +

Optical Engineering, Vol. 32, Issue 3, (March 1993). https://doi.org/10.1117/12.61043

Abstract

We have improved the stability and temporal response of the laser speckle strain gauge that detects strain from speckle displacement caused by surface deformation. In the gauge, a narrow laser beam is incident on a diffuse surface, and speckle patterns appearing in the light scattered through the symmetrical angles are detected by a pair of linear image sensors. Speckle displacement is derived by a real-time correlator as the peak of the cross correlation between the current frame and a reference frame of the sensor driven at 1000 frames per second. The reference frame is fixed until the correlation peak becomes lower than a threshold. Using a pair of image sensors, followed by the correlators, and a laser of output power of a few tens of milliwatts, we could measure dynamic strain of polymer films at the frequency between a fraction of hertz and 100 Hz. The resolution of the gauge, which only depends on geometry of the optical system and the sensor pitch, is a few tens of microstrains. The upper limit of the measurement can be extended arbitrarily because small incremental strain is integrated.

Citation Download Citation

Ichirou Yamaguchi, Tamiki Takemori, and Koichi Kobayashi "Stabilized and accelerated speckle strain gauge," Optical Engineering 32(3), (1 March 1993). https://doi.org/10.1117/12.61043

Published: 1 March 1993

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE