摩擦型连接高强螺栓节点的疲劳性能分析

FATIGUE PERFORMANCE ANALYSIS OF FRICTIONAL HIGH STRENGTH BOLTS JOINTS

基于断裂力学疲劳裂纹扩展理论,分析了摩擦型连接高强螺栓疲劳性能与连接接触面摩擦系数和温度的关系。建立摩擦型高强螺栓3维有限元模型,计算其在不同摩擦系数和温度下的疲劳寿命和疲劳损伤。结果表明:摩擦型连接高强螺栓节点的疲劳寿命随着摩擦系数的增加而降低,随温度的增加而降低。抗摩擦系数越大疲劳损伤越严重,温度越高结构的疲劳损伤也越大。随摩擦系数增加,接触面的几何不连续程度增加,导致裂纹的扩展速率加快、结构的安全系数降低;随温度的升高,结构的安全系数降低。研究成果可为今后相关构件的疲劳设计提供参考。

According to the fatigue crack extension theory of the fracture mechanics, it was analysed the relationship between the property of the high-strength bolts and the connection surface friction coefficient, as well as that between the property of the high-strength bolts and temperature. The fatigue life and fatigue damage degree under different anti friction coefficient and different temperature were calculated by high-strength bolt three-dimension FEM model. After recycling for the same times, the fatigue life would decrease with the increase of the anti-fiction coefficient as well as the temperature. The bigger the anti friction coefficient, the more serious the fatigue damage. The higher the temperature, the more serious the fatigue damage degree. With the increase of the anti-friction coefficient, the structure safety factor would decrease, for the increased anti-friction coefficient made the connection surface geometric discontinuities degree become serious, then the crack extension rate would be faster. With the increase of the temperature, the structure safety factor would also decrease. The conclusions could be used as a reference for the future fatigue design of such components.