USA As Represented by Secretary of the Navy

Thomas S Ramotowski

Patrick J Monahan

Charles D Spellman

Qiming Zhang

Monica L Blanchard

John R Welch

George J Kavarnos

Donald C Portofee

Gerald J Roche

Edward H Dzwilewski

James M LeBlanc

Rachel E Blanchard

Zachary R Golebieski

Anthony S Poirier

A mold is configured to make several identical single lap shear test samples according standards at one time. The mold can be made from aluminum and cast pieces of silicone rubber. The mold's shorter sides have slots designed to hold rigid substrates. The rigid substrates are inserted into the slots after the area to be bonded has been coated with adhesive. The opposing slots for each sample are offset so that the substrates overlap by the prescribed amount in the standard in the center of the mold. Spacer pieces are provided between the substrates. The slots and spacer pieces hold the substrates rigidly together to ensure a thin adhesive bondline between the two rigid substrates.

Single lap shear test sample mold

A test fixture is provided with a pair of specimen molds. Each specimen mold includes a cylindrical specimen barrel with at least one open end with a guide rail attached to a bottom of the specimen barrel. The test fixture also includes a support body having a trough shaped to match the shape of the specimen barrel. A track is located at the bottom of the trough and extends the length of the trough. The specimen barrels are positioned in the support body having an open end of a first specimen barrel facing the open end of a second specimen barrel. The guide rail for each specimen barrel is positioned in the track at the bottom of the trough in the support body.

Resin gel-time test fixture

An electrical connector for joining a cable to a cathodically protected body in a marine environment includes a connector body having a terminal connector for joining to the cathodically protected body and a mounting portion for receiving the cable. An elastomeric band is positioned around said connector body mounting portion and exerts radially compressive inward force thereupon. An encapsulant is formed around and bonded to said connector body mounting portion, said elastomeric band and the cable. A method for making the electrical connector is further provided.

Undersea cable connector with internal debonding prevention

A method for improving service life in a connector for joining to a cathodically protected platform includes providing a metallic connector for joining to a cable. A non-conductive coating is provided on the connector proximate the cable. A hydroxide ion diffusion distance is determined that will insure dilution of hydroxide ions to a level that will prevent damage to an encapsulant and non-conductive coating bond on the connector. A polymer encapsulant is molded around the non-conductive coating and the cable to seal the assembled cable in the connector such that the encapsulant and non-conductive coating bond is formed at a greater path distance than the determined hydroxide ion diffusion distance from any hydroxide ion source.

Cathodic debonding prevention method and apparatus

A method for conducting a peel test of a polymer coated metallic sample includes making a peel test specimen having a polymer joined to a substrate. A free portion of the polymer is left unattached to the substrate. The peel test specimen is positioned in an environment for testing in such a manner that the polymer is allowed to peel downward from the substrate. A weight is joined to the free portion of the polymer and a start time is recorded. The attached portion of the polymer is periodically measured and the elapsed time is recorded. A peel rate is calculated from the measurement and time.

Coated metallic sample peel test

An electrochemical engine for buoyancy is provided with the engine having a water-tight and gas-tight chamber containing a volume of seawater. The electrochemical buoyancy engine contributes electrons for reduction of hydrogen protons in the seawater using a sufficient voltage applied to an anode and a cathode disposed in the seawater. The generated hydrogen gas is held in the chamber to provide the desired buoyancy and can be vented to adjust the buoyancy.

Electrochemical buoyancy engine for autonomous undersea platforms

A method is provided for applying a superhydrophilic coating to a surface of a sonobuoy and acoustic sensors. A variety of different processed and chemistries can be used to make superhydrophilic coatings including polyethylene glycol, titanium dioxide and nanoporous silica. Application to the surface can be by dipping, painting and spraying. Once applied to the outer surface of the acoustic sensor and specifically the sonobuoy, the sonobuoy can be handled/stored/deployed under existing procedures. Titanium dioxide and nanoporous silica are inorganic materials that would have to be inter-mixed with the coating. The coating allows a surface of the sonobuoy to wet completely upon immersion into a fluid thereby minimizing the formation of air bubbles on the surface whereby the suppression of bubble formation allows the sonobuoy to immediately generate high quality acoustic data.

Superhydrophilic coatings for improved sonobuoy performance

This invention is an acoustic device protected by an acoustically transparent low water permeability encapsulant made from an acoustically clear polymer such as polyurethane. High aspect ratio clay nanoparticles are positioned in the substrate in overlapping layers with layers of the substrate interposed. The invention also provides a method for forming an acoustically transparent low permeability encapsulant about an acoustic device. The method includes treating high aspect ration clay nanoparticles to make them organophilic. The treated nanoparticles are then mixed in a polymer resin in such a way as to form an intercalated mixture. A curing agent is added to the mixture, and the mixture is allowed to set. When set the resulting intercalated mixture produces an acoustically clear, low permeability polymer coating.

Ultra-low permeability polymeric encapsulated acoustic device and method

An epoxy and rubber microcomposite is formed by adding a carboxy-terminated or amine-terminated rubber component having a glass transition temperature less than zero degrees centigrade to a bisphenol A based epoxy resin component; heating the mixture to 150 degrees centigrade; cooling and curing with a suitable curing agent. A phase segregation occurs between the epoxy resin component and the rubber component to form discrete, spherical rubbery domains with the epoxy compound. Because the glass transition temperature of the rubbery domains is below zero degrees centigrade; the rubbery domains act as acoustic windows within the high-modulus epoxy compound.

Microcomposite with improved acoustic impedance

A method for preventing accumulation of organisms on a surface exposed to a marine environment. Nano-particles are provided in a water soluble polymer. The nano-particles have a thickness of about 2 nanometers and a major surface area of about 3 microns and are treated by a quaternary ammonium salt. The treated nano-particles are mixed into the water soluble polymer material. This mixture can be applied to the exposed surface. Biofouling is prevented by the sharpness of the nano-particles, sloughing of the water soluble material, and biocidal action caused by the quaternary ammonium salt.

Method and apparatus for preventing biofouling of surfaces

Method for improving acoustic impedance of epoxy resins

A method for computing activation energy of diffusion for a material in a liquid is provided. At least two identical samples of the material are submerged in the liquid at different temperatures. The time required for each sample to reach a goal weight percentage is measured. A reaction acceleration factor is computed for the two samples from the resulting times and temperatures. Activation energy of diffusion is computed from the reaction acceleration factor and the temperatures. Additional samples can be used to give an error estimate.

Activation energy measurement method

A dampening material is presented with a carboxy-terminated butadiene nitrile (CTBN) as a dampening element. The glass transition temperature of the CTBN is generally at room temperature. The material is a two-component system with micro-scale phase segregation. The CTBN is reacted into an epoxy resin at a high temperature and cooled to allow the epoxy to react with a curing agent. A phase segregation occurs between the epoxy and the CTBN as the epoxy gels/cures. The extent of phase separation in the reaction is controlled by cross-linking and gelling. The rubbery component of CTBN phase segregates and forms discrete, spherical domains. Because the glass transition temperature of the rubbery domains is in the operational temperature range of interest, the composite is capable of absorbing acoustic energy. A high modulus allows a larger amount of acoustic energy to enter the composite where it is absorbed by the rubbery CTBN component.

Mixing and curing carboxy-terminated butadiene-nitrile rubber, epoxy resin and curing agent

A method and test apparatus for carrying out testing on a variety of samples of polymer bonded to metal wherein the samples are subjected to an accelerated cathodic reaction causing cathodic delamination of the samples. In particular, the method and test apparatus include a closed vessel that is partially filled with synthetic ocean water. An impressed current system is employed to protect the metal component of the samples. The synthetic ocean water is heated with an external band heater raising the temperature of the synthetic ocean water to thermal levels exceeding normal ocean temperatures in order to accelerate the reaction. Pure oxygen is then introduced into the closed vessel at a desired pressure to dissolve the oxygen into the synthetic ocean water to further simulate natural ocean conditions.

Method and test chamber for accelerated aging of materials and bonds subject to corrosion related degradation

The present invention is a new class of terpolymers for use as high strain electrostrictive polymer films. More particularly, the invention is a class of electrostrictive terpolymers comprising vinylidene fluoride (VDF), trifluoroethylene (TrFE) and at least one monomer having at least one halogen atom side group. The monomer is preferably an ethylene-based monomer and preferably selected to favor gauche-type linkage along the polymer backbone. The halogen atom side group is preferably large enough to move or cause adjacent polymer chains to be farther apart from or away from each other than in the absence of such side group, but not so large that it would inhibit polymer crystallites from forming. The monomer is preferably a chloro-monomer such as chlorofluoroethylene (CFE). The chlorofluoroethylene (CFE) is preferably 1-chloro-2-fluoroethylene or 1-chloro-1-fluoroethylene. The chlorofluoroethylene (CFE) favors gauche-type linkage which favors high electrostrictive strains.

Growing community of inventors

Tiverton, RI, United States of America

Thomas S Ramotowski