Joint Army Navy NASA Air Force

Mission Area I: Service Life / Missile Sustainment

Methodology for service life prediction and assessment

• Aging systems - surveillance, service life prediction, extension
• Factors which limit the service life of propulsion systems and propellants, such as chemical/structural aging, changes in binder/filler interaction, crystallization, migration/diffusion of ingredients or moisture
• Development approaches for improving service life of solid rocket motors and liquid rocket components
• Motor monitoring - NDE methodologies applicable to service life evaluation
• Factors which limit service life of structural sub-components (nozzles, cases, igniters, combustion chambers, tanks, etc)
• Hazards related to service life and aging

Mission Area II: Materials Properties and Characterization

New developments or application experiences related to mechanical properties and characterization.

• Effects of propellant formulation on gun tube wear and erosion (GTWE)
• Fundamental molecular modeling related to gun tube wear and erosion
• New and/or improved test methods for evaluating materials used in liquid engine components or liquid engine propellant tanks
• New and/or improved test methods for evaluating propellant and case or component construction materials' mechanical properties including tensile, shear, friability, dilatation and bulk, fracture, microstructure, aging, propellant/case bond, etc.
• New and/or improved approaches to material properties optimization during solid rocket motor or gun propellant development
• Advancements in test equipment and procedures, test instrumentation, data acquisition and processing techniques, and data reduction and analysis
• Test specimen preparation techniques and dynamic characterization
• Mechanical properties related to propulsion systems hazards, e.g., material characterization under impact loads or high loading rates

Mission Area III: Structural Analysis and Design

Evaluation and validation of structural analysis methods applicable to initial design, structural integrity, and service life prediction of propulsion systems.

• Advancements in the state-of-the-art in structural analysis, particularly in nonlinear viscoelastic analysis and incorporation of nonlinear constitutive behavior
• Cumulative damage, failure criteria, and thermal and moisture diffusion analysis are included in these areas
• Structural reliability analyses and analysis of nondestructive evaluation results relative to structural reliability are two areas of particular interest
• Approaches to incorporating the results of NDE in a structural analysis code and methods of evaluating the effects of defects on structural integrity are of particular interest
• Applications of nonlinear elastic-plastic analysis to design of metal components, such as cases and pressure vessels
• Application of structural analysis methods to health-monitoring sensors, including sensor design, influence of sensors on motor integrity, and interpretation and application of sensor data

Mission Area IV: Experimental Structural and Mechanical Analysis and Test Methods

Evaluation of stress measurement tools and techniques for liquid rocket engines and solid rocket motors, analog rocket motor design, analysis and testing.

• State-of-the-art experimental structural methods
• Technology for experimental stress analysis
• Experimental validation of stress analyses and failure analyses
• Experimental investigation of rocket motor structural/ballistic interactions
• Statistical considerations in experimental stress analysis
• Experimental structural analysis and test methods for rocket motor cases, nozzles, and gun propulsion systems
• Experiments related to the fundamental chemistry occurring between gun barrel materials and combustion products
• Macroscopic erosion experiments leading to chemical mechanisms occurring in gun tube wear and erosion

Mission Area V: Nondestructive Evaluation

Nondestructive evaluation and inspection techniques to solid propellant rocket motors, liquid or gel engines, and gun propulsion systems and components.

• Application of NDE techniques during any portion of the life cycle of the propulsion components
• Application of NDE technology and methods for enhancing propulsion system and/or subcomponent quality and reliability
• Use of NDE methods during the propulsion system life cycle from manufacturing to acceptance (buy-off)
• The monitoring and control of manufacturing processes
• Automated NDE sensing systems for quality control and conformance testing
• Use of embedded sensing system (including Micro-Electromechanical Systems – MEMS) for performance testing
• NDE methods used during static test
• NDE standards for system or component acceptance
• NDE methods for health management
• Role of NDE in service life assessment and extension
• Evaluation of propulsion system aging characteristics
• The post-acceptance evaluation of grain integrity, inert materials aging, chemical attack and migration, corrosion, and environmental storage effects
• Use of NDE technologies in strategic sustainment
• Advanced NDE systems and technologies, including but not limited to, real-time radiography, digital ultrasonics, holography, shearography, computed tomography, acoustic emission, electro-optic fiber embedments, thermography, lasers, and advanced digital image analysis techniques
• Emerging NDE technologies and their potential application to the propulsion community

Mission Area VI: Defect Evaluation

Evaluation of the criticality of flaws and defects to the structural integrity of propulsion systems

• Improved methods for predicting crack growth and cumulative damage in viscoelastic materials and solid, liquid and gun propulsion system component materials.
• Applications of crack propagation and fracture theory in structural analysis finite element codes.
• Structural/ballistic interaction, e.g., analysis of pressure-driven crack propagation in a propellant grain.

Mission Area VII: Processing and Characterization of Additively Manufactured Materials

New or significantly improved methods for manufacturing solid rocket motor or solid-fueled propulsion systems or solid explosive systems (or components thereof)

• Development of additive manufacturing (AM) methods (e.g. fused deposition modeling, direct ink writing, robocasting, stereolithography) for energetic materials
• Material, formulation and process development and optimization of energetic materials to enable effective additive manufacturing
• Advanced manufacturing methods for inert components of propulsion or energetic systems, including automated fiber placement for composite components or AM methods for metallic components
• Methods for automating one or more manufacturing steps to improve speed, repeatability, safety, or other characteristics
• Non-destructive evaluation techniques, particularly in-situ or non-disruptive evaluation techniques that complement advanced manufacturing methods
• Design and analysis methods, techniques, and tools to assess materials and systems produced using manufacturing methods described in this mission area, to include those that address service life, reliability and critical defects assessments
• Studies that assess the merit of applying manufacturing methods described in this mission area to particular systems or classes of systems
• Development of Lot Acceptance Test (LAT) methods to measure the burn rate and mechanical properties that are efficient and effective for materials produced by additive manufacturing, to include alternatives to casting or extruding blocks of propellant to make burn rate strands and/or JANNAF dog-bones