Structural Health Integrated for Enhanced Lightweight Design (SHIELD) Rocket Motor Cases

The Dynovas team’s Structural Health Integrated for Enhanced Lightweight Design (SHIELD) rocket motor cases (RMCs) enable lightweighting of composite motor cases, rapid case qualification, and real-time assessment of non-visible damage. The SHIELD rocket motor cases can be >30% lighter weight then metallic cases (driven be case bending stiffness) and with more volume available for propellant than traditional composite cases (driven by higher temperature capable motor case and reduced insulation requirements). The benefits of SHIELD RMCs are realized through the integration of composite hard points (bosses, lugs, rails), hybrid processing with tension optimized filament/tape winding and load path tailoring around embedded hardpoints via tailored fiber placement (TFP), and use of emerging insulations that enable higher temperature processing of higher temperature capable composite materials (>550 °F). The structural build can be completed with existing reinforcing fibers (such as domestically sourced IM7, IM10, or T1100) for which significant material data exists both in CMH-17 and AGATE databases. The reinforcements can be coupled with damage resistant matrices and ply stack-ups to improve the composite cases lifecycle performance (toughened high temperature resins, thermoplastic interleaves, and/or thin ply architectures). The statistical material properties can be correlated to case performance through strain measurement by a network of fiber optic sensors (FOS). The FOS network produces 10,000’s of strain data points for rapid correlation with less test articles. The FOS can be automatically integrated into the wind (reducing cost associated with touch labor) and produce a 3D map of the composite structures’ strain life and identification of non-visible defects (fiber angles, residual strains, pressure cycles, delamination, fiber gaps, etc.) from pre-cure through the entire lifecycle of the motor case.                Dynovas’ SHIELD RMCs replacement of traditional metallic rocket motor cases utilizes a three-fold comprehensive approach: 1) a clear path towards integration as a complete rocket motor assembly; 2) TRL and MRL advancement of the composite case itself with a realized weight and/or performance (e.g., volume of propellant) benefit when considering missile assembly and attachment to aircraft suspension equipment (MIL-STD-8591); and 3) qualification that includes compliance to insensitive munitions requirements (MIL-STD-2105), missile structural integrity (MIL-M-8856B), E3 stability (MIL-STD-464), and risk burn down through empirically driven data. At the completion of Phase I, Dynovas will demonstrate the SHIELD RMCs at TRL 3. In Phase II, the SHIELD RMCs will be demonstrated at TRL 6 via ground based relevant environment testing, including thermal cycling, shock, vibe, and combined load structural testing. Dynovas will also conduct a risk reduction hot fire test.