In-Situ Determination of Coating Material Acoustic Properties.

摘要

This report documents the progress on grant N00014-96-0175, In-Situ Determination of Acoustic Parameters of Navy Coatings for Mold In-Place Application. The objective of the project is to develop a method for in-situ determination of acoustic quality and performance of the mold in-place coatings. The physical parameters which determine the acoustical performance are the complex longitudinal and shear moduli and the density. These properties will be determined in-situ by driving the coating with a broadband transient impulse and measuring the surface motion at several points using a laser Doppler probe. During the first year, the Laser Doppler Velocimetry measurement system was assembled and tested. Measurements taken on representative materials using the system and other conventional methods compared favorably. Investigation of several signal processing methods to resolve the multiple reflections was initiated. Future work will include application of these signal processing methods to more extensive coating samples as well as refinement of the measurement technique.