Estimating Flaw Size Distributions From Service Inspection Results (Preprint)

Abstract

A key component of risk analyses of aging aircraft is the distribution of flaw sizes that are present in the aircraft. This distribution can be derived from teardown inspections of retired aircraft; however it is more cost effective to use the results of service inspections. Using the sizes of found cracks can be misleading however because nondestructive inspections are not perfect so some cracks are missed. Furthermore, the likelihood that an individual crack is detected is a function of the size of the crack when inspected and the crack size distribution is related to the number of flight hours the aircraft has experienced. An approach for estimating flaw size distributions from inspection results is derived and illustrated from data and simulation results. Problems with estimating both the POD function and the crack size distribution are discussed and a method for setting the reset crack size after an inspection based on the sizes of detected cracks is suggested.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2006
Accession Number
ADA476910

Entities

People

  • Jeremy Knopp
  • Peter W. Hovey

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Aircrafts
  • Distribution Functions
  • Inspection
  • Military Research
  • Probability
  • Probability Density Functions
  • Random Variables
  • Reliability
  • Risk
  • Risk Analysis
  • Simulations
  • Spreadsheet Software
  • Statistical Analysis
  • Test And Evaluation
  • United States

Readers

  • Statistical inference.
  • Structural Health Monitoring of Composite Structures.