The proposed program will integrate off-the-shelf, operationally proven approaches and technologies to formulate a comprehensive system methodology to safely determine the fatigue lives of helicopter structural components based upon actual operational usage. The development of the system methodology include the following specific approaches: (1) Identification of health and usage monitoring system (HUMS) flight parameters required to sufficiently define the flight regimes experienced by structural components during operational usage. (2) Establishment of methods for effectively recognizing the flight regimes and the amount of time, or number of events, that occur in each regime. (3) Determination of the rate at which structural components accumulate damage in each of the flight regimes. (4) Assessment of Pareto-type approaches for achieving (1), (2) and (3) by ensuring conservative, rather than precise, results. For example, data that are difficult or expensive to acquire might be conservatively estimated. (5) Evaluation of each step of the process to ensure that the resulting structural component fatigue lives maintain the required level of structural reliability. The comprehensive system methodology that is developed to safely determine the fatigue life of structural components will (1) monitor and evaluate structural component fatigue damage accumulation and improve safety, maintainability, and cost, and (2) ensure the structural reliability that results from the process. The fatigue damage accumulation will be used to schedule structural component maintenance, overhaul, and replacement. The methodology will have applications to any mechanical system with fatigue-critical structural components for which the repeated loading can be determined. These applications include many military and civilian systems: aircraft, land vehicles, ships, power generators, industrial machinery, fixed structures (bridges, seaport cranes, off-shore oil rigs, etc) and others.
Keywords: Structural Reliability, Structural Fatigue, Structural Component, Structural Strength, Health And Usage Monitoring System, Flight Regime, Regime
