悬挂运输结构夹板式螺栓节点疲劳可靠性分析

Fatigue reliability analysis of splint-type bolt joints in hanging transportation structures

夹板式螺栓节点在各类轻工业建筑的悬挂运输轨道中广泛应用,近年来也逐渐被汽车生产工业建筑所选用。然而某采用该类连接节点的小型汽车生产厂房,在使用1到5年内,该类连接节点螺栓陆续发生断裂。通过螺栓断面分析、现场吊杆应力与螺栓轴力测试、有限元计算分析及疲劳强度验算,揭示了该类节点在小型汽车工业厂房中的断裂属于疲劳破坏,采用Monte Carlo法,进行了该类节点在小型汽车生产厂房中的疲劳可靠性分析,指出若设计时仅考虑静力强度,其疲劳可靠指标较低,失效概率较高,建议该类节点在汽车生产工业建筑中应用时,进行疲劳强度验算。

Splint-type bolt joints are widely used in the hanging transportation structures of various light industrial buildings.In recent years,they have gradually been used for automotive industrial buildings.However,in a small automobile production plant that adopts this type of joint,the bolts of such connection joints fractured one after another within five years after the factory was completed.Through bolt fracture surface analysis,on-site boom stress and bolt axial force testing,finite element calculation analysis and fatigue strength check,it was revealed that the fracture of this type of joint in the small automobile industrial plant was a fatigue failure.The Monte Carlo method was used to analyze the fatigue reliability of this type of joint which was used in small car production plants.It was pointed out that the fatigue reliability index was lower and the failure probability was higher if merely the static strength was taken into account in the design.It was recommended that such joints should be evaluated for fatigue strength when they are used in automobile production industrial buildings.