|Physics of Failure for Military Platform Critical Subsystems|
|Applied Vehicle Technology|
Failure Modes and Effects Analysis, Lifing, Modelling Simulation, Probability of Failure
NATO has established 10 Science and Technology priorities to guide technology strategic planning and execution. The S&T priority for “Platforms & Materials focuses on enhancing the performance of physical platforms in operations, covering the spectrum from individual armour to manned and unmanned platforms in the sea, land, air, and space domains. Includes lighter (improved mobility, more efficient)… and more maintainable platforms.”
There is a need to continuously improve sustainment of ageing aircraft through characterization and creation of physics-based material failure models. This is also fundamental to enabling a family of limited function, rapidly produced, low cost, attritable and autonomous UAVs by trading pristine component manufacturing to one that allows increased imperfection. Further still, physics-based failure models play will play a vital role to additively manufactured parts that have larger fractions of voids and microstructural anomalies. A new physics-based failure understanding for designs, materials, and manufacturing will be required for advancements in all of these areas.
Aging fleets across NATO nations--coupled with the need to develop very low cost, small to medium size systems for targeted applications--are driving the need for physics-based models for design and lifing. In particular, requirements for short-life and attritable applications will be enabled by aggressive, lower-cost designs. Aggressive designs in this regime will challenge current empirical life prediction capabilities, elevate importance of competing mechanisms such as creep and fatigue, and will challenge existing design criteria and available data. These same rules and tools would be available across a broad range of systems to address aging fleet issues, as well as emerging and farther future systems.
Past AVT experience has examined capabilities and needs at particular scales. These activities include: AVT-211 (Understanding Failure Mechanisms of Composites for Sustaining and Enhancing Military Systems Structures); AVT-172 (Condition Based Maintenance); AVT-212 (Application of Integrated Munition Health Management); AVT-220 (Structural Health Monitoring of Military Vehicles); AVT-222 (Continuing Airworthiness of Ageing Aircraft Systems); AVT-223 (Cross-Domain Integrated System Health Management Capability); AVT-242 (Coated Component Condition Assessment and Remaining Life Prediction for Advanced Military Air Vehicles); AVT-250 (Gas Turbine Engine Environmental Particulate Foreign Object Damage); AVT-252-RTG (Stochastic Design Optimization for Naval and Aero Military Vehicles); and AVT-ST-006 (Exploitation of Additive Manufacturing in NATO). In many ways this AVT technical activity proposal is the natural extension of this foundational work.
The proposed RSY will:
? Identify common interests as well as opportunities and challenges in physics-based life quantification methods to address rapidly changing needs for conventional materials as well as new materials operating in extreme environments;
? Illustrate how an understanding of the physics of failure could bring about improved attritable propulsion and air vehicles that provide new capability to the warfighter, quicker and in a more reliable way;
? Outline new physics-based approaches to predict the remaining useful life of fielded and future propulsion and airframe systems.
? Describe the potential use of physics-based lifing models for additively manufactured components.
Modeling & Simulation (M&S): Physics-based models are required, which faithfully describe complex failure mechanisms. To be useful, these models need calibration through analysis and testing, and validation through design and field experience.
Design Approaches to Life Prediction: It is necessary to address deterministic, probabilistic and “combined analysis” (probabilistic + field experience) approaches--and their payoffs from application. Of particular interest are approaches to take into account effects and complex interactions of microstructure and environment on various failure modes (e.g., creep-fatigue-environment interactions); and approaches for life prediction and validation in the low-life regime.
Manufacturing: Additive manufacturing (AM) presents unique opportunities to enable radical new designs, significantly reducing part count, coupled with the potential to reduce defects/failure rates. However, there are challenges to understanding physics of failure and damage mechanisms in specific AM processes (e.g., Direct Metal Laser Sintering, Direct Metal Deposition, Binder Jet, etc); as well as inspection, acceptance/rejection of AM components.
? Maintenance/Sustainment: We must modernize our maintenance/sustainment processes to be able to fight and win the wars of the future. One way we can do this is by incorporating the use of digital computing, analytical capabilities, and new technologies to conduct engineering in more integrated virtual environments to increase customer and vendor engagement, improve threat response timelines, foster infusion of technology, reduce cost of documentation, and impact sustainment affordability. Therefore, there is significant interest in: The role of Non-Destructive Evaluation (NDE) during maintenance to minimize failure probability; and quantification of inspection sensitivity and reliability to aid modeling and simulation
? Development of Artificial Intelligence (AI)/Machine Learning assisted NDE for life extension;
? “Big Data” analysis of large data bases containing failure and risk information, thereby facilitating approaches to prevent failure and reduce maintenance costs; and
? Diagnostics and prognostics to provide autonomous logistics and material management