带过焊孔焊接细节疲劳性能优化及试验研究

Optimization and Experimental Study of Fatigue Performance of Welded Details with Cope Holes

为了提高带过焊孔焊接细节的疲劳寿命,以某钢桁梁桥为背景,针对其翼缘板和斜腹杆的焊接构造,通过在过焊孔处填半圆弧板和焊缝错开的形式对其疲劳性能进行优化,制作带过焊孔焊接细节和优化模型的试件,进行疲劳试验测试其疲劳寿命,并结合有限元分析对比各模型的疲劳性能,验证优化措施对疲劳性能的改善效果。结果表明:在过焊孔处填半圆弧板可有效改善带过焊孔焊接细节的局部应力集中现象,提高其疲劳寿命,在高应力幅作用时效果更加显著;对接焊缝错开可显著提高带过焊孔焊接细节的疲劳寿命,其改善效果优于在过焊孔处填半圆弧板,在实际工程结构中推荐优先采用。

To improve the fatigue lives of the welded details with the cope holes, a steel truss girder bridge was cited as an example and with regard to the welded structures of the flange plate and diagonal web member of the bridge, the fatigue performance of the welded structures was optimized by means of filling the semicircular arc plates and staggering the welded joints at the cope holes. The specimens of the welded details with the cope holes and the optimization models were prepared, the fatigue tests for the specimens were made and the fatigue lives of the specimens were examined. With reference to the finite element analysis, the fatigue performance of the different optimization models was compared and the effect of the optimization on the improvement of the fatigue performance was verified. The results demonstrate that the filling of the semicircle arc plates at the cope holes can effectively improve the local stress concentration in the welded details with the cope holes, improve the fatigue lives of the welded details and the effect is even more significant under the high stress amplitude. The staggering of the welded joints can significantly improve the fatigue lives of the welded details, the effect of the improvement is better than that of the filling of the semicircle arc plates and it is hence recommended that the priority should be given to the application of the staggering of the welded joints to the practical engineering structures. © 2017, Journal Press, China Railway Bridge Science. All right reserved.