Measurement of Dynamic Crack Opening Displacement by Moire Interferometry.

Displacement Discontinuity Analysis of the Effects of Various Hydraulic Fracturing Parameters on the Crack Opening Displacement (COD)

    The combination of horizontal drilling along with hydraulic fracturing has significantly improved the production of hydrocarbon reservoirs and made it possible to extract the relatively impermeable and uneconomical reservoirs. The production rate of oil and gas wells increases proportional to hydraulic fracture aperture or crack opening displacement (COD). This is an important parameter i...

Precision displacement measurement by active laser heterodyne interferometry.

We demonstrate an active laser heterodyne interferometer which can automatically compensate environmental disturbances and is capable of precision displacement measurement. Two Zeeman He-Ne lasers were employed. Laser II was used as the light source to stabilize the interferometer by using a piezomirror in a feedback loop. The hetereodyne signal of the two lasers was used to directly calibrate ...

Measurement of Thermomechanical Behavior of Solder Joints under Power Cycling Condition Using Moire Interferometry

Failure mechanisms exposed by environmental accelerating testing methods such as thermal cycling or thermal shock test, may differ from those at the service operating conditions. While the device is heated up or cooled down evenly on its external surface during environmental testing, real operating powered devices experience temperature gradients caused by internal local heating, components’ di...

Subnanometer Displacement Measurement Using Common-path Grating Interferometry

Three-Dimensional Continuous Displacement Measurement with Temporal Speckle Pattern Interferometry

A speckle interferometer which can measure whole field three-dimensional displacements continuously and dynamically has been built. Three different wavelength lasers are used to produce the speckle interferograms of the two in-plane displacements (displacements in the x- and y-direction) and one out-of-plane displacement (displacement in the z-direction), respectively. One color CCD camera is e...