arl research facilities
Scanning Laser Vibrometry
The application of effective noise and vibration treatment often requires a precise knowledge of the spatial and temporal distribution of the source vibration. Researchers at ARL have developed considerable expertise in the use of a laser technique, scanning laser vibrometry, which is sensitive, robust, and greatly facilitates solving vibration problems since it measures the full-field surface vibration. Structural acousticians are able to couple this information with special post-processing techniques to reveal optimum areas for damping or structural changes to bring about effective noise and vibration reduction.
Water Scan of Rotor Blade
Considerable research in experimental structural acoustics as well as laser vibrometry is conducted at ARL Penn State. Numerous publications in these fields (the most recent includes a vibrometry article in the April 1997 Review of Scientific Instruments) attest to the extensive use of these systems in research at ARL Penn State. Expertise in computational acoustics complements this technology by providing predictions of radiated sound from the laser vibrometer data.
ARL Penn State has well-maintained support facilities and can adapt these systems for laser vibration studies in special conditions, such as in water tunnels, wind tunnels, anechoic chambers, or reverberant tanks.
ARL is actively pursuing new applications and extensions of this growing technology such as: wave decomposition techniques for computing in-plane and out-of-plane structure-borne intensity; methods for extracting three-dimensional vibration fields from nonplanar surfaces; nondestructive evaluation; and measurement of the vibration of rotating machinery.