University of Illinois Urbana-Champaign

Transient analysis of fatigue crack propagation under step increase in loading

Majumdar, Saurindranath

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https://hdl.handle.net/2142/112119

Description

Title
Transient analysis of fatigue crack propagation under step increase in loading
Author(s)
Majumdar, Saurindranath
Issue Date
1974-05
Keyword(s)
  • Fatigue
  • Crack Propagation
  • Step Increase
  • Loading
Abstract
In a previous report, steady state crack propagation at a constant stress intensity factor range was analyzed on the basis of a cumulative fatigue damage model. In this model, the points ahead of a crack tip were assumed to constitute a series of uniaxial fatigue specimen and fatigue crack propagation was viewed as the successive fatigue failure of these specimens. In this report an extension of the previous analysis to a situation involving an increase in the stress intensity factor range from a lower level to a higher level is carried out. The analysis indicates that there is a transient zone through which the crack has to grow before attaining the full steady state crack propagation rate corresponding to the higher load level. Numerical results have been computed for three steels of comparable ductility but with widely varying yield strength. The results show that both the crack length increment and the number of cycles involved in the transient period decrease with increasing yield strength. Also, for any given steel, the crack length increment during the transient increases with the load ratio but the number of cycles is independent of the load ratio.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 388
  • 1974-6010
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112119
Sponsor(s)/Grant Number(s)
Advanced Research Projects Agency, ARPA Order No. 2169, 74/05
Copyright and License Information
Copyright 1974 Board of Trustees of the University of Illinois

Owning Collections

Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.