Qc. Zhang et al., DYNAMIC STRAIN-MEASUREMENT BY OPTICAL SPECKLE CORRELATION METHOD USING LCTV PANELS, Optics communications, 101(3-4), 1993, pp. 133-138
A new noncontacting dynamic strain measurement technique using optical
speckle correlation is presented. Two LCTV panels placed symmetricall
y with respect to the incident laser beam are modulated with the initi
al speckle patterns and used as shadow filters. Speckle movement can b
e converted into light intensity variation. A strain wave excited unde
r a shock loading through impact on an aluminum cantilever was measure
d. The results agreed well with the strain wave monitored by an electr
ical strain gauge.