提出了广义DFR(细节疲劳额定值)概念,基于疲劳寿命遵循对数正态分布规律推导了任意应力比、可靠度和置信度下的DFR值的计算公式,在此基础上,发展了基于广义DFR概念的连接件谱载疲劳寿命估算方法,试验测定了铆钉单搭铝合金连接件和螺栓连接合金钢连接件的广义DFR值和谱载疲劳寿命。采用本文提出的广义DFR方法估算了两种连接件的谱载疲劳寿命,并与试验结果进行对比,发现理论估算结果与试验数据吻合良好。
This paper proposed the generalized DFR concept and formulation at a given stress ratio, reliability and confidence level from fatigue life following the logarithmic normal distribution. New approach based on the generalized DFR concept was developed to predict fatigue lives of mechanical joints subjected to spectra loading from minimal dataset. Fatigue tests were conducted to determine the generalized DFR values of riveted aluminium alloy over - lap joints and bolted alloy steel joints under constant amplitude loading and fatigue lives under spectra loading. Good correlation is a- chieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed method.