FATIGUE DAMAGE DURING TWO-LEVEL BIAXIAL-STRESS TESTS.

Abstract

Two-level cumulative damage fatigue tests were conducted under biaxial stress conditions for a selected ratio of principal stresses. The tests were conducted in a machine imposing alternating torque and axial force on tubular specimens of mild steel. It was observed that when the lower stress levels were followed by the high stress levels the cycle-ratio sums were greater than unity. When the higher level stresses were applied first, the sums were less than one, as has been observed in the case of uniaxial fatigue. The Miner and the Henry criteria for predicting damage under uniaxial stress were applied to these biaxial stress conditions. The Henry criterion was observed to be more accurate. A modified Henry criterion is proposed for biaxial-stress fatigue, and a concept of negative damage is introduced. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1967
Accession Number
AD0815020

Entities

People

  • Allan A. Blatherwick
  • Norman D. Viste

Organizations

  • University of Minnesota

Tags

DTIC Thesaurus Topics

  • Biaxial Stresses
  • Fatigue Tests (Mechanics)
  • Materials Testing
  • Stress Tests
  • Stresses

Readers

  • Mathematical Modeling and Probability Theory.
  • Military Leadership and Professional Education.
  • Structural Health Monitoring of Composite Structures.