Open AccessFatigue strength of SS400 steel under non-proportional loading
Author(s) -
Takahiro Morishita,
T. Takaoka,
Takamoto Itoh
Publication year - 2016
Publication title -
frattura ed integrità strutturale
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.368
H-Index - 19
ISSN - 1971-8993
DOI - 10.3221/igf-esis.38.39
Subject(s) - materials science , composite material , metallurgy , structural engineering , engineering
This study discusses fatigue properties of low carbon steel, type SS400 steel, under non-proportional loading. Multiaxial fatigue tests under proportional and non-proportional loading conditions with various stress amplitudes were carried out using a hollow cylinder specimen at room temperature. In the test, three types of stress paths were employed. They are a push-pull, a reversed torsion and a circle loading. The circle loading is a cyclic loading combined the push-pull and the reversed torsion loading in which axial and shear stress waveforms have 90 degrees phase differences. From the obtained test results, poor evaluations of failure life under non-proportional loading are indicated when the life is correlated by the equivalent strain range based on von Mises Δεeq and the non-proportional strain range ΔεNP. A modified strain parameter is presented which can evaluate the failure life in high and low strain levels under non-proportional loadin