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Laser Optics Test Bench Complete

ISE has completed work on our laser optics test bench. The focal point is our newly built one-watt Class IV 655nm continuous wave (CW) laser capable of high levels of visible illumination and particle scatter in our laboratory research.

Our big scary laser, besides being used for holography experiments, the study of various gas transition phases under examination in the lab, and the detection of damage in specially and generally orthotropic composites, has the uncanny ability to burn through gloved hands, ignite dark objects, ruin digital cameras if not properly positioned, heat water, and oh yes, blind you instantly. Needless to say, an entire set of safety protocols and interlocks has been incorporated into the design to keep the experiments safe. Despite this, we've been having a lot of fun tinkering around with it and figuring out ways to incorporate it into different research projects.

Up until about a decade ago, a one-watt CW laser would have been confined only to the largest research complexes or university settings. Hat's off to the inventor of the laser diode. The photo, done for visual effect, shows the effect of the laser being shined lengthwise through a simple glass prism.

Composite Non-Destructive Inspection

ISE is currently developing a robust method for the determination of structural defects within laminated composite aerospace structures. The current method under development uses a mathematically derived specially-orthotropic lamination model subjected to sensitivity perturbations from empirically-derived dynamic transfer-function data.

Predicted failure areas, precipitated by a decrease in signal coherence between test points, and an increase in the residual modal forces are screened under a statistical failure model using the maximum strain energy (Beltrami) theory and maximum distortion energy (von Mises) theory as indicators of areas of delamination of plies, disbonding of joints, or void detection.

Currently an en engineering proof-of-principle exercise, ISE hopes to adapt the method ultimately into an onboard damage detection monitoring system for in-flight aircraft. The photo to the right shows one of the many tests being performed to quantify the extent of disbonding and delamination within an eight-ply woven composite panel specimen having a NASA ply configuration of [0/45/0/-45]S and an EA-956 resin.

R-Wave Seismic Blasting Model

The ISE Rayleigh Wave (R-Wave) seismic vibration prediction model hit another milestone in 2011 in development by being able to accurately predict surface freight and commuter rail motion to within an accuracy of one-foot (actual mileage may vary depending on how good your soil data is).

For years, the model has been routinely able to handle multiple blasting sources with accuracy far greater than that predicted by the DuPont equation or any of the widely used semi-empirical methods found in the journals or the ISEE Blaster's Handbook. Now, incorporating the eigenfunctions from years of modal analysis of different soil types has improved the accuracy of less-impactive sources greatly.

The R-Wave model is still, alas, a research tool requiring the user to know what he/she is doing to get accurate results. In the right hands, though, the results are spectacular. The photo is a sample output showing our favorite hypothetical one-kiloton underground nuclear blast.

Mass Spectrometry at ISE

ISE has again raised the environmental bar to new levels by adding Mass Spectrometry to our list of in-house air quality monitoring services. Our SRS UGA300 mass spectrometer also allows our research staff to expand its investigative research capabilities down to the atomic level.

With the ability to detect materials having weights up to 300 atomic mass units (AMU's), and rapidly compare test samples against 192,262 different chemical compounds using the NIST08 Mass Spectral Library database search program, the use of mass spectrometry allows ISE to quantify with great accuracy test samples for heavier and more difficult to detect elements and compounds such as lead, mercury, arsenic, as well as radioactive gasses such as Radon.

The photo shows a standard Tedlar bagged air sample being tested.