Sonar dome
The Invention is a reinforced plastic sonar dome having a low acoustical insertion loss combined with sufficient mechanical strength. Acoustical and structural fibers are stochastically mixed and formed into a blended yarn. The blended yarn is woven into a blended fabric. The blended fabric is ordered into a stack having multiple layers of blended fabric. The blended fabric is incorporated into a polymer resin while the polymer resin is in liquid form using a vacuum assist. The acoustical fibers and the vacuum assist modify the acoustical properties of the resulting composite sonar dome.
1. A method for making a sonar dome, the method comprising:
a. creating a plurality of substantially stochastic fiber mixtures, each of said plurality of substantially stochastic fiber mixtures being created by mixing a predetermined quantity of acoustical fibers and a predetermined quantity of structural fibers;
b. creating a plurality of blended yarns, each of said plurality of blended yarns being created from a one of said plurality of said substantially stochastic fiber mixtures;
c. weaving a plurality of blended fabrics from said plurality of said blended yarns, each of said plurality of blended fabrics having a one of a plurality of ratios of said acoustical fibers to said structural fibers;
d. ordering said plurality of said blended fabrics based upon said ratio of said acoustical fibers to said structural fibers of each of said plurality of blended fabrics;
e. stacking said ordered plurality of said blended fabrics to form a blended and ordered stack;
f. incorporating a polymer resin into said blended and ordered stack by applying a partial vacuum to draw said polymer resin into said blended and ordered stack when said polymer resin is in a liquid form, wherein the sonar dome has an inside surface and an outside surface, said step of ordering said plurality of blended fabrics based upon said ratio of said acoustical fibers to said structural fibers of each of said plurality of said blended fabrics comprises: ordering said blended fabric such that said ratio of said acoustical fiber to said structural fiber for a one of said plurality of said blended fabrics proximal to said inside surface is greater than said ratio for a one of said plurality of said blended fabrics distal to said inside and said outside surface, and ordering said blended fabric such that said ratio of said acoustical fiber to said structural fiber for another one of said plurality of said blended fabrics proximal to said outside surface is greater than said ratio for a one of said plurality of said blended fabrics distal to said inside and said outside surface.