Smart Thermal Activated Vents for Large Solid Rocket Motors

Many advanced military weapon systems involve solid rocket motor (SRM) to achieve supersonic speed. Most SRM casings are made from metal alloys. There is an increasing number of SRMs fabricated from polymeric composites because of high performance to weight ratio. The propellants in SRMs are highly sensitive to the chamber pressure to maintain combustion. However, the high chamber pressure has a safety concern in case of fire or unplanned external stimuli. Current safety design incorporates an explosive device to split the motor casing in case of fire or elevated temperature. The use of explosive with close contact with the propellant is itself a concern for safety. In this Phase I SBIR project Wright Materials Research Co. will team up with ATK Thiokol to fabricate and test a new design of fast venting mechanism for SRM casing for MDA’s missile applications. The proposed technology is based on a smart material approach. It will create a vent quickly to release the high chamber pressure and extinguish the fire as the desired condition is reached. This design is reliable, safe, and can be adopted for technology insertion in the near future. Preliminary research results are very promising. Once developed through the Phase II project, the proposed smart material based venting mechanism would have an immediate niche market for missiles applications including THAAD, PAC-3, SM, GBI, KEI, and many others.