Risk Analysis for Modeling Damage at Multiple Sites

Abstract

In this first phase of a two phase study to develop a computer program for risk analysis of fatigue damage at multiple sites, the computer code PROF was demonstrated to be applicable to the multi-element damage (MED) problem. The application requires the damage tolerant analysis and crack size input for each of the relevant structural elements and for the relevant combinations of intact and failed conditions of the subcritical structural elements on the critical elements. The demonstration was preformed incorporating the effects of two subcritical elements on the failure probability of the chordwise joint at WS405 of the C-141 airframe. The application of PROF in the MSD area is not as clear. Since the largest crack in a lap joint will grow the fastest, the population of crack sizes to be modelled should be defined in terms of the largest crack in the zones of equivalent stresses. The sizes of the cracks in the holes immediately adjacent to the largest crack must be accounted for but several studies have indicated that the sizes of the cracks in more remote holes are not important drivers. Reasonable scenarios can be defined to bound the fracture probabilities given complete damage tolerant analyses and crack size data.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1994
Accession Number
ADA361253

Entities

People

  • Alan P. Berens
  • Joseph P. Gallagher
  • Subrato Dhar

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Airframes
  • Commercial Aircraft
  • Composite Structures
  • Computer Programs
  • Computers
  • Crack Tips
  • Damage Tolerance
  • Finite Element Analysis
  • Geometry
  • Materials
  • Mechanics
  • Probability
  • Risk
  • Risk Analysis
  • Stress Intensity Factors
  • Yield Strength

Readers

  • Computational Modeling and Simulation
  • Materials Science (Mechanical Engineering).
  • Regression Analysis.