炭素鋼の回転曲げおよびねじり二段二重重複繰返し応力による疲労寿命

概要

論文の詳細を見る
Studies on fatigue behavior of carbon steel under varying stress conditions have been done up to now by various workers. The majority of those studies, however, were conducted under rotating bending or tension-compression, and there were only few studies under torsion. The purpose of the present study is to investigate the torsional fatigue behavior under multiple repeated load in two stress levels. Carbon steel S30C was used as the specimen and fatigue tests were conducted under rotating bending. torsion and combination of them. The conclusions obtained are summarized as follows: (1) Independently of the stress sequence, the cumulative cycle ratio Σn/N is larger than unity under torsion. (2) Variation of surface hardness during secondary stress repetition respectively corresponds to the cumulative cycle ratio Σn/N under either rotating bending. torsion or combination of them. Namely, when the cumulative cycle ratio Σn/N is larger than unity, the surface hardness increases, and when smaller than unity, decreases. (3) Variation of plastic strain amplitude during secondary stress repetition roughly corresponds to the cumulative cycle ratio Σn/N under torsion. When the cumulative cycle ratio Σn/N is considerably larger than unity, the plastic strain amplitude is smaller than that in constant stress amplitude test.
社団法人日本材料学会の論文
1974-09-15