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Title:Effects of mean stress and prestrain on fatigue damage summation
Author(s):Topper, T.H.; Sandor, B.I.
Subject(s):Stress
Prestrain
Fatigue Damage
Abstract:A cumulative damage procedure based on smooth specimen tests of 2024-T4 aluminum alloy and aircraft quality SAE 4340 steel is formulated in which the effects of prestrain and mean stress on fatigue life are investigated separately. It is assumed that life reductions due to prestrain or mean stress at a given strain level may be separately incorporated into a simple cycle ratio damage summation. Small plastic prestrains are shown to cause considerable life reductions. Larger prestrains appear to have little additional adverse effect. It was found possible to adequately correlate results with and without mean stress by a parametric representation of mean stress and strain amplitude. Analysis of arbitrary stress-strain sequences indicates that the proposed damage summation procedure gives adequate life predictions. Cycle ratio summations were close to one for both stress controlled and strain controlled tests in which sequence, number of blocks, fraction of life at mean stress, and the life fraction at which plastic straining occurred were all varied.
Issue Date:1968-08
Publisher:Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report:TAM R 318
1968-0374
Genre:Technical Report
Type:Text
Language:English
URI:http://hdl.handle.net/2142/112044
ISSN:0073-5264
Sponsor:Aeronautical Structures Laboratory, Naval Air Engineering Center, Contract No. NOO-156-67-C-1875
Rights Information:Copyright 1968 Board of Trustees of the University of Illinois
Date Available in IDEALS:2021-11-04


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  • Technical Reports - Theoretical and Applied Mechanics (TAM)
    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.

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