号数 ばね論文集41号(1996年)
ページ数 pp.65-110
種類 共同研究報告
論文名 大たわみ回転曲げ疲労試験方法標準化に関する研究
Title Standardization for Large Deflection Rotating-bending Fatigue Testing Method
著者 ばね技術研究会
Author Research Committee on Standardization for Nakamura-type Rotating-bending Fatigue Testing Method
抄録 中村式回転曲げ疲労試験は広く使用されているが,試験法の不統一からデータの相互比較が困難であった欠点を改善するため,現状の調査研究を行い,標準的な試験法の案を提示した。従来,曲げ応力の設定には,単純な弾性梁理論による線形解を採用しているが,荷重が大きい時,大たわみ理論により計算すべきであり,応力設定での問題点や手順を考察した。データのばらつきの比較から,たわみ制御法の方が荷重制御法よりも優れている。ブシュ寸法,材質の影響も調査し,大たわみ理論による計算プログラムも示した
Abstract  Nakamura-type rotating-bending fatigue test has been widely used in order to evaluate the fatigue strength of wire, because of its simplicity and rapidity.
 However it has been used for the relative comparison within results obtained by own institution, it was difficult to compare the results with data obtained by other institutions, because its standard testing method has not been established.
 Considering these background, actual problems of the conventional method were investigated, and load-controlled method and deflection-controlled method were tested in order to compare the scattering of static bending stress and dynamic fatigue life.
 Furthermore, some factors which cause scattering were checked in detail.
 On the basis of these investigations, this committee proposed a new standard testing method.
 In this study, the following facts were mainly clarified.
(1)Load-controlled method has been conventionally used in many institutions, and the bending stress is calculated by using the linear solution based on the beam bending theory.
(2)Bending stress should be calculated by using the equation based on the large deflection theory.
(3)Deflection-controlled method is superior to load-controlled method comparing the amounts of scattering of data.
(4)By measuring the deflection, true stress can be estimated even in load-controlled method.
(5)Most useful bush which has good wear resistance and low friction is made from ultra high molecule polyethylene.
著者の所属  
Belonging  
Key Words Nakamura-type rotating-bending, Large deflection theory, Beam bending theory, Deflection-controlled method, Load-controlled method