随机振动载荷下连接螺栓振动疲劳强度分析

Analysis of Bolt Vibration Fatigue under Random Vibration Load

因连接螺栓在随机振动试验中存在疲劳破坏问题需要解决,采用基于功率谱密度函数的频域法,对连接螺栓随机激励下的振动疲劳寿命进行分析。通过有限元分析计算出连接螺栓上的载荷,理论计算得出连接螺栓上的1σ振动应力,基于高斯分布和线性累积损伤定律的三区间法,结合材料17-4PH的S-N曲线,对连接螺栓进行随机振动载荷下的振动疲劳强度进行分析。结果表明:计算与试验结果一致,为连接螺栓振动疲劳寿命预计提供分析手段和设计参考。

To solve the problem of fatigue failure on of bolt in random vibration test,the random vibration fatigue life is estimated by finite element method.The method is based on the information of the frequency domain of random loading history.Bolts are simulated by rigid connection.The stress transfer function of the structure is analyzed by frequency response simulation,and obtained peaks per second of the bolt.The force and the stress of bolt was picked.The stress of bolt are calculated.Combined with S-N curve of and fatigue damage accumulation theory,random vibration fatigue life of bolt is analyzed by Three-band method.Both the calculation and test result are basically consistent.This method can be provided as provide analysis method and design reference for bolt.