Fatigue strength of small-notched specimens under variable amplitude loading within the fatigue limit diagram

Y. Kondo, C. Sakae, Masanobu Kubota, S. Nagamatsu

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Although the fatigue limit diagram is defined in principle for constant stress amplitude, it is often considered that fatigue failure would not occur, even in varying loading, if applied stresses were kept within the fatigue limit diagram. However, it was shown in the case of small-notched specimens that fatigue failure occurred in some special cases of variable amplitude loading, even when all stress amplitudes were kept within the fatigue limit diagram. The cause of this phenomenon was examined using two-step stress and repeated two-step stress patterns in which the first step stress was chosen to be equal to the fatigue limit with zero mean stress and a mean stress was superposed on the second step stress. A non-propagating crack was formed by the first step stress. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure occurred even when all stress amplitudes were kept within the fatigue limit diagram. It was an unexpected fracture caused by the interference effect of a non-propagating crack and a mean stress change.

Original languageEnglish
Pages (from-to)301-310
Number of pages10
JournalFatigue and Fracture of Engineering Materials and Structures
Volume30
Issue number4
DOIs
Publication statusPublished - Apr 1 2007

Fingerprint

Fatigue of materials
Cracks
Fatigue strength

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Fatigue strength of small-notched specimens under variable amplitude loading within the fatigue limit diagram. / Kondo, Y.; Sakae, C.; Kubota, Masanobu; Nagamatsu, S.

In: Fatigue and Fracture of Engineering Materials and Structures, Vol. 30, No. 4, 01.04.2007, p. 301-310.

Research output: Contribution to journalArticle

@article{5a466c8c2b1a49fda7cabe45909c2d5d,
title = "Fatigue strength of small-notched specimens under variable amplitude loading within the fatigue limit diagram",
abstract = "Although the fatigue limit diagram is defined in principle for constant stress amplitude, it is often considered that fatigue failure would not occur, even in varying loading, if applied stresses were kept within the fatigue limit diagram. However, it was shown in the case of small-notched specimens that fatigue failure occurred in some special cases of variable amplitude loading, even when all stress amplitudes were kept within the fatigue limit diagram. The cause of this phenomenon was examined using two-step stress and repeated two-step stress patterns in which the first step stress was chosen to be equal to the fatigue limit with zero mean stress and a mean stress was superposed on the second step stress. A non-propagating crack was formed by the first step stress. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure occurred even when all stress amplitudes were kept within the fatigue limit diagram. It was an unexpected fracture caused by the interference effect of a non-propagating crack and a mean stress change.",
author = "Y. Kondo and C. Sakae and Masanobu Kubota and S. Nagamatsu",
year = "2007",
month = "4",
day = "1",
doi = "10.1111/j.1460-2695.2007.01106.x",
language = "English",
volume = "30",
pages = "301--310",
journal = "Fatigue and Fracture of Engineering Materials and Structures",
issn = "8756-758X",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Fatigue strength of small-notched specimens under variable amplitude loading within the fatigue limit diagram

AU - Kondo, Y.

AU - Sakae, C.

AU - Kubota, Masanobu

AU - Nagamatsu, S.

PY - 2007/4/1

Y1 - 2007/4/1

N2 - Although the fatigue limit diagram is defined in principle for constant stress amplitude, it is often considered that fatigue failure would not occur, even in varying loading, if applied stresses were kept within the fatigue limit diagram. However, it was shown in the case of small-notched specimens that fatigue failure occurred in some special cases of variable amplitude loading, even when all stress amplitudes were kept within the fatigue limit diagram. The cause of this phenomenon was examined using two-step stress and repeated two-step stress patterns in which the first step stress was chosen to be equal to the fatigue limit with zero mean stress and a mean stress was superposed on the second step stress. A non-propagating crack was formed by the first step stress. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure occurred even when all stress amplitudes were kept within the fatigue limit diagram. It was an unexpected fracture caused by the interference effect of a non-propagating crack and a mean stress change.

AB - Although the fatigue limit diagram is defined in principle for constant stress amplitude, it is often considered that fatigue failure would not occur, even in varying loading, if applied stresses were kept within the fatigue limit diagram. However, it was shown in the case of small-notched specimens that fatigue failure occurred in some special cases of variable amplitude loading, even when all stress amplitudes were kept within the fatigue limit diagram. The cause of this phenomenon was examined using two-step stress and repeated two-step stress patterns in which the first step stress was chosen to be equal to the fatigue limit with zero mean stress and a mean stress was superposed on the second step stress. A non-propagating crack was formed by the first step stress. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure occurred even when all stress amplitudes were kept within the fatigue limit diagram. It was an unexpected fracture caused by the interference effect of a non-propagating crack and a mean stress change.

UR - http://www.scopus.com/inward/record.url?scp=33947526747&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33947526747&partnerID=8YFLogxK

U2 - 10.1111/j.1460-2695.2007.01106.x

DO - 10.1111/j.1460-2695.2007.01106.x

M3 - Article

AN - SCOPUS:33947526747

VL - 30

SP - 301

EP - 310

JO - Fatigue and Fracture of Engineering Materials and Structures

JF - Fatigue and Fracture of Engineering Materials and Structures

SN - 8756-758X

IS - 4

ER -