为了描述缺口根部应力均方根(RMS)的集中程度,给出了缺口件在动态载荷激励下的应力均方集中系数的定义及其计算公式。基于结构疲劳的基本机理,通过考察缺口根部应力均方根的分布特点,给出了疲劳缺口系数的计算公式,形成了缺口件振动疲劳寿命分析的名义应力法。通过3个算例的计算结果表明,本文提出的方法能很好地预测缺口件的振动疲劳寿命。
To describe the centralized level of the stress root mean square (RMS) around a notch, this paper proposes a definition and calculation formula of the stress mean square concentration factor for notched specimens under dynamic excitation. A calculation formula for notch fatigue factor is presented based on the basic fatigue mechanism of structures and a consideration of the distribution characteristics of the stress root mean square in dangerous regions around a notch. Consequently the nominal stress approach for the life prediction of notched specimens under vibration loading is obtained. The results of three typical examples show that the method proposed in this paper can predict the vibration fatigue life of notched specimens well.
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