4aEA10. Sonar dome deflection and strain measurement system.

Session: Thursday Morning, May 16

Time: 10:30

Author: Joel F. Covey
Location: Naval Res. Lab., Code 7135, Washington, DC 20375-5350
Author: Diane B. Weaver
Author: Jonathan B. Walker
Location: SFA, Inc.


A multiplexed computer-controlled deflection and strain measurement system has been developed for use in performing at-sea data collection on a Naval surface ship sonar dome rubber window. The deflection of the window is measured at 128 points on its water-filled inner surface by an acoustic time-of-flight technique. At each point of interest a 2-cm-diam hemispherical acoustic transducer is pulsed at 110 kHz and the signal is received by an array of four similar transducers fixed to the ship's sonar array. Ten different receiver arrays are used to allow for direct line-of-sight reception for each of the points of interest. The 85 strain sensors were built into the wire plies of the window by the manufacturer (B. F. Goodrich). The system records data from all 128 transducers, all strain sensors, as well as numerous environmental parameters at a rate of approximately 200 reading/s. The measurement system is nonobtrusive to normal ship sonar operations and performance. The data collected is being used in characterizing the behavior of these windows at high speeds and sea states and in the calibration of numerical experiments and window redesign efforts. [Work supported by NAVSEA.]

from ASA 131st Meeting, Indianapolis, May 1996