高强螺栓节点腐蚀疲劳可靠度分析

针对高强螺栓裂纹尺寸与临界裂纹尺寸的概率密度函数相交可能发生疲劳破坏的问题,本文对高强螺栓腐蚀疲劳可靠度计算模型进行研究。分析了高强螺栓节点在腐蚀环境下的疲劳可靠度,并采用Gerberich-Chen公式,估算高强螺栓腐蚀裂纹扩展门槛值,同时基于断裂力学理论和结构可靠度理论,导出高强螺栓腐蚀疲劳可靠度计算模型,并以M24高强螺栓节点为例,对高强螺栓节点应力及受力进行计算,计算结果表明,螺栓最大使用应力为572MPa,高强螺栓节点腐蚀疲劳可靠度为0.994 5。该计算模型可以充分利用现有设计资料、数据,较方便地计算高强螺栓腐蚀疲劳可靠度,进而预测高强螺栓的疲劳寿命,为高强螺栓节点腐蚀疲劳计算分析提供了理论参考。

Reliability Analysis of High-Strength Bolt Joint Corrosion Fatigue

If the probability density functions of crack size and the critical crack size interfered, high- strength bolt may be destroyed. Reliability model of high-strength bolt joint corrosion fatigue was estab- lished and the reliability of high-strength bolt joint corrosion fatigue was analyzed. Based on the fracture mechanics theory, according to the Gerberich-Chen formula, the corrosion fracture growth threshold value of high-strength bolt was estimated. According to fracture mechanics method, based on reliability theory, the high-strength bolt corrosion fatigue reliability model was deduced. And a M24 high-strength bolt stress status was analyzed. The results showed that the max operating stress of high-strength bolt was 527 MPa and the reliability of the high-strength bolt joint corrosion fatigue was 0. 994 5. It was easy and convenient using existing data to analyze high-strength bolt joint corrosion fatigue reliability by this model. Hence the high-strength bolt joint corrosion fatigue can be predicted. ＂This method may provide the reference for the high-strength bolt joint fatigue analysis.