Typical Ground Vibration Tests of ight vehicles are performed by attaching a moderate number (10 to 100) of discrete accelerometers to a free-free ight vehicle where the excitation is provided using one or more electro-mechanical shakers. A new approach involves using a noncontacting scanning laser vibrometer on the free-free ight vehicle. The SLV has the advantage over discrete accelerometers in that a near in nite number of data points can be measured without altering the mass con guration of the ight vehicle. This large number of data points makes it easy to: (a) correlate the experimental data with analytical ( nite element) results, (b) investigate local modes, and (c) investigate the a ects of subtle vehicle con guration changes on the modal properties. Dr Kosmatka is working with Northrop-Grumman to develop and use this new approach to evaluate their Hunter MQ-5B Unmanned Air Vehicle.
Professor John B. Kosmatka