Residual life estimation of cracked aircraft structural components

Residual-life estimation for components with non-symmetric priors

Condition monitoring uses sensory signals to assess the health of engineering systems. A degradation model is a mathematical characterization of the evolution of a condition signal. Our recent research focuses on using degradation models to compute residuallife distributions for degrading components. Residual-life distributions are important for providing probabilistic estimates of failure time...

Structural Health Monitoring of Wind Towers: Residual Life Estimation

Elastic-plastic fracture toughness and fatigue crack growth resistance of full penetration butt welds were experimentally investigated. The obtained results were used to predict the critical crack size and the time to structural collapse of weld joints typically adopted in tubular towers of windmills. For this purpose, heavy in-service loading conditions were considered. In this way, it was pos...

Managing Life-Cycle Information of Aircraft Components

When an aircraft component needs replacement of a serially controlled item, a maintenance officer in the U.S. navy uses the Scheduled Removal Component (SRC) card to confirm the component's life cycle, to verify that the part is ready-for-issue, and to verify how many flight-hours it still has left. Unfortunately, replacement components are often missing the SRC cards. Further, when the cards a...

Conditional Mean Residual Life Estimation

Smooth estimation of mean residual life

Abstract: We propose here a smooth estimator of the mean residual life function based on randomly censored data. This is derived by smoothing the product-limit estimator using the Chaubey-Sen technique (Chaubey and Sen (1998)). The resulting estimator does not suffer from boundary bias as is the case with standard kernel smoothing. The asymptotic properties of the estimator are investigated. We...