NASA Scientific and Technical Aerospace Reports

adaptive and/or active methods of controlling the structural acoustic response of panels to reduce the transmitted noise1. A
finite element formulation was recently developed to study the dynamic response of shape memory alloy (SMA) hybrid
composite panels (conventional composite panel with embedded SMA fibers) subject to combined acoustic and thermal
loads2. Further analysis has been performed to predict the far-field acoustic radiation using the finite element dynamic panel
response prediction3. The purpose of the present work is to validate the panel vibration and acoustic radiation prediction
methods with baseline experimental results obtained from an isotropic panel, without the effect of SMA.
Author
Acoustic Attenuation; Acoustic Measurement; Prediction Analysis Techniques; Sound Pressure; Sound Waves; Vibration
Measurement
20040111463 Scripps Institution of Oceanography, La Jolla, CA
Wave Breaking, Bubble Production and Acoustic Characteristics of the Surf Zone, SIO Component
Deane, Grant B.; Jun. 2001; 7 pp.; In English
Contract(s)/Grant(s): N00014-99-1-0260
Report No.(s): AD-A425368; No Copyright; Avail: CASI; A02, Hardcopy
The objective of the research component reported here was to make long-term measurements of acoustic telemetry and
channel probe signals propagated through the surf zone simultaneously with measurements of the shoaling surf, the clouds of
bubble entrained by breaking waves and the nearshore circulation driving bubble advection. The purpose of these
measurements was to: (1) statistically characterize the surf zone acoustic channel Doppler and time spreads, and acoustic
drop-outs, in terms of the incident wave field and (2) make sufficiently detailed environmental and acoustic measurements to
understand the deterministic coupling between the telemetry signals, the surface gravity wave field and wave-induced bubble
clouds.
DTIC
Acoustic Properties; Bubbles
20040111481 Scripps Institution of Oceanography, La Jolla, CA
Wave Breaking Bubble Production and Channel Characterization of the Surf Zone
Deane, Grant B.; Aug. 2003; 7 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): N00014-00-1-0303
Report No.(s): AD-A425436; No Copyright; Avail: CASI; A02, Hardcopy
The long-term goal of this research is to understand underwater acoustic communications propagation through the surf
zone. A secondary goal was to see if high- intensity, transient sound caustics created by shoaling surf could be exploited to
improve the detection of buried objects in the surf zone.
DTIC
Bubbles; Underwater Acoustics
20040111641 Pennsylvania State Univ., University Park, PA
Acoustics in New Materials
Maynard, Julian D.; Sep. 2002; 11 pp.; In English
Contract(s)/Grant(s): N00014-01-1-0019
Report No.(s): AD-A425744; No Copyright; Avail: CASI; A03, Hardcopy
The technical objectives of this research are to determine the physical properties of new materials with emphasis on thin
films deposited on substrates. For the most part, experiments will involve the measurement of elastic constants and damping.
As derivatives of the free energy with respect to atomic positions, elastic constants are a sensitive probe of the environment
in which all physical processes take place within a solid; they are a particularly important probe of phase transitions. For
studies of thin films on substrates, these measurements will yield information about how the film and substrate interact and
modify behavior.
DTIC
Acoustics
20040111653 Naval Research Lab., Stennis Space Center, MS
Relationships Among Sediment Physical and Acoustic Properties in Siliciclastic and Calcareous Sediments
Richardson, Michael D.; Briggs, Kevin B.; Sep. 23, 2003; 7 pp.; In English
Report No.(s): AD-A425758; NRL/PP/7430-03-9; No Copyright; Avail: CASI; A02, Hardcopy
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