Program Manager: Leo Christodoulou, Ph.D.
 The major limitation in the readiness of combat systems/platforms is the lengthy inspections with the resultant conservative "fly, no-fly " operation decisions made to avoid the failure of materials in critical components. Additionally, aircraft are tracked in fleet averages whereas flight leaders define the damage limits and operational lifetime of assets in the fleet. The goal of the Prognosis program is to manage this “fear of failure” through the determination of remaining usable life and the quantitative prediction (Prognosis) of future operating capability. As a result, commanders will have the ability to adaptively manage, deploy, and use combat systems/platforms that otherwise would have been removed from service.
The technical objective of the Prognosis effort is to transform life expectancy from the old statistical method to one based on the true diagnosis of the system materials and critical components. This will enable a transformation in platform sustainment and asset management, which will provide fleet-wide improvement to combat system readiness. Both power-train (gas turbine engine and gearbox) and airframe subsystems were chosen as the “testbeds” for this program because they are responsible for frequent inspections, non-availability, and operational costs in defense platforms (air, land, sea, manned, or unmanned).
The Structural Integrity Prognosis System (SIPS) effort under the Prognosis program is a multi-year effort to develop models and sensors to predict remaining useful life and performance in structures. The SIPS concept combines physics models, state awareness, and historical data to provide multi-level reasoning of the damage state of critical areas within a platform structure. Novel methods for interrogating materials (local and global) that capture the intrinsic behavior of materials have been developed. This knowledge is then fed into predictive models and physics-based algorithms for how and when materials fail. These models―when combined with mission history, maintenance data, and information regarding the system state (i.e., sensor data)―can quantitatively represent the life expectancy of an aircraft structure.
The Engine System Prognosis (ESP) effort was a multi-year effort focused on the F100 and F110 turbine engines. It has provided a suite of prognostic health management capabilities for these engines, with direct applicability to other engines. Four critical areas of the turbine engine were addressed: Fan/Compressor Airfoil Module, Turbine Disk Module, Hot Gath Path Module, and Bearing Module. Program-developed, physics-based, multi-scale models that describe the failure and damage accumulation in engine materials have been developed to predict the cascading effects on future engine performance. An engine reasoner has been developed to incorporate sensed and mission data with engine performance models for each system-critical module to provide an evaluation of component and entire system health. The engine system reasoner concept will enable decision-makers to determine maintenance plans and predict readiness on a mission-by-mission basis.
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