Choice of Materials on the Basis of Random Vibration and Structural Fatigue,

Abstract

A method is presented for the evaluation of alternative materials to be used in structures subjected to random low cycle excitation. The fracture criterion is based upon the revised Palmgren-Miner cumulative damage hypothesis in terms of plastic deformation. It is then used with a given statistics of random low cycle loading in the formulation to compute the expected value and variance of the life. As a numerical example, two aluminum alloys, one with high strength but low ductibility (2024-T4; yield strength 52 ksi and 'true strain' at fracture 0.35) and another with low strength but high ductibility (6061-T6 yield strength 25 ksi and 'true strain' at fracture 0.45) are considered as alternative materials for use in an idealized beam subjected to random excitation. In this particular case, 2020-T4 even with its higher strength gives smaller expected value of structurel life to fracture. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1970
Accession Number
AD0715273

Entities

People

  • F. D. Ju
  • H. Y. Yeh
  • J. T. P. Yao

Organizations

  • University of New Mexico

Tags

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Excitation
  • Materials
  • Plastic Deformation
  • Random Vibration
  • Statistics
  • Test And Evaluation
  • Vibration
  • Yield Strength

Readers

  • Materials Science (Mechanical Engineering).
  • Statistical inference.
  • Structural Health Monitoring of Composite Structures.