Engineers Edge - A patent has been awarded to Southeastern Louisiana University for a deformation prediction instrument developed by physicist Sanichiro Yoshida. The instrument uses optical interferometry technology to measurement elements to identify weak areas in a wide range of materials, including ferrous, nonferrous metals, plastics and other materials.

The technology could be used to identify weaknesses in structures ranging from aircraft airframes, bridge structures, as well as small elements of nanotechnology structures as small a speck of dust.

The Interferometry device utilizes multiple light paths, (typically two) from a common laser source. The light paths are directed to a location where the operator can measure exact differences in the multiple laser paths as they hit the object. The laser light waves measure with an accuracy of less than one micron. By measuring the difference in the laser light paths, a determination of the surface displacements can be measured and by analyzing the pattern of the displacements the weakness in the material can be determined.

Yoshida has been working with light and lasers since 1983 and optical interferometer since 1994, developed the mathematical procedure that determines the actual displacement from the interferometric images. Yoshida also has a another patent pending on a related development.

“This approach allows us to be able to predict where and when fractures may occur by determining the weak spot and the remaining intact life of the material,” Yoshida explained. “This has significant applications in engineering and construction technology where we could possibly do the measurements from a distance or using portable equipment.

“It also seems to work well with very small items, such as what we see in nanotechnology,” he added. “It is very hard to predict failure in small objects because the dynamics of the structures are very different, but this device seems to work with this.”

Five undergraduate students work with Yoshida in his laboratory, carrying out various experiments under his direction. Two of those students, Christopher W. Schneider of Ponchatoula and John A. Gaffney of San Pedro Sula, Honduras, will present papers on their work at the American Physical Society's annual meeting in New Orleans in March. Preliminary experiments conducted three years ago on the first version of the optical interferometer by Rashmi Manjegowda, a former Southeastern student from India helped Yoshida confirm the validity of the patented technology.

Adapted from material provided by the Southeastern Louisiana University