钢箱梁焊接咬边缺陷对构件疲劳寿命的影响

Influence of undercut welding defects on the fatigue life of steel box girders

为了解焊接咬边缺陷对钢箱梁焊接构件疲劳寿命的影响程度,采用数值模拟方式,对含有不同长度、宽度、角度等缺陷形态的构件疲劳寿命进行研究。结果表明:咬边长度越长,构件的疲劳寿命越短,咬边长度每增加1 mm,疲劳寿命降低约1.4%;咬边宽度越大,构件疲劳寿命越长,咬边宽度每增加0.1 mm,疲劳寿命提高约2%;咬边角度从45°增加至75°时,构件疲劳寿命的平均变化幅度为2.7%;咬边长度和宽度对构件疲劳寿命的影响程度大于咬边角度;相较于不存在焊接咬边缺陷的构件,存在咬边缺陷构件的疲劳寿命平均劣化程度达到了25%。

In order to understand the influence of weld undercut defects on the fatigue life of steel box girder welded members,the fatigue life of members with different length,width,angle and other defects was studied by numerical simulation.The results showed that the longer the undercut length was,the shorter the fatigue life of the component was.The fatigue life decreased by 1.4%when the undercut length increased by 1 mm.The larger the undercut width was,the longer the fatigue life of the component was.The fatigue life increased by about 2%when the undercut width increased by 0.1 mm.When the undercut angle increased from 45°to 75°,the average variation of fatigue life was 2.7%.The influence of undercut length and width on fatigue life was greater than that of undercut angle.Compared with the components without weld undercut defects,the average deterioration of fatigue life of components with undercut defects reached 25%.