钢桥焊接构件疲劳寿命预测

Fatigue Life Prediction for the Welded Members in Steel Bridges

分析了影响焊接接头疲劳寿命的各种因素 ,在Dugdale模型基础上构造出裂纹闭合模型 ,并将其应用到焊接接头的表面半椭圆形裂纹 ,其中考虑了热影响区的材性变化、焊接残余应力以及焊缝几何带来的应力集中 .通过与两个试验结果的比较表明 :该法能估计裂纹扩展阶段的疲劳寿命 ,可用于焊接钢桥抗疲劳设计 .

In this paper the various factors affecting the fatigue life of welded joints are analyzed.Based on the Dugdale model a crack closure model has been established and applied to the surface half elliptical crack in welded joints.The changes of material behavior in HAZ(heat affecting zone),the residual stress and the stress concentration due to the weld profile have been taken into account.The comparison with two experiments shows that the method proposed in this paper can predict the fatigue life of crack propagation in welded joints.It can be used for the fatigue design of steel bridges.