FATIGUE LIFE ESTIMATION PROCESSES UNDER CONDITIONS OF IRREGULARLY VARYING LOADS.

Abstract

The fatigue life estimation processes, under the condition of irregularly varying service loads, which are at present employed by designers of structural systems, particulary aircraft, are reviewed and discussed. The characteristics of service load time histories are discussed in general and for several structures in detail. The counting methods for reducing an irregularly varying load time history to a population of cyclic loads are subsequently treated in some detail while the power spectrum method is mentioned for the sake of completeness. The dependence of a load spectrum on the counting method is outlined. An essential part of the report deals with methods of fatigue life estimation, mainly with the linear cumulative damage hypothesis and program testing. The principles of both of these methods and their accuracy are discussed.

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1967
Accession Number
AD0821258

Entities

People

  • Gerhard Jacoby

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Accuracy
  • Aircrafts
  • Airframes
  • Counting Methods
  • Cyclic Loads
  • Diffraction
  • Fatigue Life
  • Mechanical Structure
  • Power Spectra
  • Spectra
  • Wave Phenomena

Fields of Study

  • Engineering

Readers

  • Structural Health Monitoring of Composite Structures.
  • Theoretical Analysis.