An Empirical Model for Loading Ratio Effect on Fatigue Crack Growth Rate Data

Abstract

Based on a limited amount of 72 F (22 C), positive loading ratio, constant amplitude loading fatigue crack growth test data generated for aluminum alloy 7010-T73651 a mathematical model of the data shift with loading-ratio was formulated. The mathematical model is only applicable to the Paris region of material behavior, and approximates the log-Paris coefficient as a linear relationship of the loading ratio. Using the model a predictive Paris equation was formulated for an unexplored loading ratio prior to the generation of any data at this test-case loading ratio. Following generation of data at the test- case loading ratio and the calculation of the best fit Paris equation to the data set it was found to agree extremely well with the predictive equation formulated beforehand. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1981
Accession Number
ADA111265

Entities

People

  • Russell R. Cervay

Organizations

  • University of Dayton

Tags

DTIC Thesaurus Topics

  • Aeronautical Laboratories
  • Air Force
  • Aluminum
  • Aluminum Alloys
  • Amplitude
  • Chemical Composition
  • Data Sets
  • Fatigue Tests (Mechanics)
  • Government Procurement
  • Governments
  • Intensity
  • Materials
  • Materials Laboratories
  • Mathematical Models
  • Mechanical Properties
  • Stress Corrosion
  • Tensile Properties

Readers

  • Computational Fluid Dynamics (CFD)
  • Materials Science (Mechanical Engineering).
  • Regression Analysis.