Intrinsically Damped Resin for "Silent" Electric Propulsion Motor

Electrical propulsion motors (EPMs) on surface ships and submarines require acoustic damping for "silent" operation; however, little has been done to dampen vibrations radiating from motor surfaces and shafting systems. Foster-Miller proposes to dampen EPM noise by making their impregnation resins intrinsically energy-absorbing. In Phase I, we will team with a commercial shipbuilder, an EPM manufacturer, experts in analytical motor acoustic modeling and a resin expert, to apply a "self-damped resin" (SDR) to the EPM. This new resin system will provide a paradigm shift in EPM acoustic damping performance. The SDR will absorb energy over a broad range of frequencies (1Hz to 15KHz) and temperatures (-40°C to +120°C), maintain structural integrity and be processible via vacuum-infiltration. We will apply our team's combined experience in acoustic modeling, SDR design and synthesis and VARTM processing to provide the U.S. Navy with a complete evaluation of key technical issues; including, tailoring the SDR in acoustic and structural properties, vacuum-processing the SDR into motor windings and measuring acoustic and mechanical properties. Phase I will demonstrate feasibility of producing SDRs that exhibit target acoustic and strength properties. In the Option, our team will demonstrate acoustic damping in control and SDR motorettes. (P-030564)