随机车辆荷载作用下斜拉桥索梁锚固区疲劳性能分析

Fatigue Performance Analysis of Anchorage Zone for Cable-Stayed Bridge Under Random Vehicle Loads

为探讨大跨斜拉桥锚拉板结构在随机车辆荷载作用下的疲劳性能,以西固黄河大桥为工程背景,利用大型通用有限元分析软件ANSYS建立了西固黄河大桥整体有限元模型,以及锚拉板的局部有限元模型,在随机车辆荷载作用下对其锚拉板结构的应力状况和疲劳性能进行了分析研究。分析结果表明,移动荷载作用下在锚拉板与锚拉管连接焊缝端部引起的应力值最大,其余焊缝的应力水平较低;对不同路径的数值分析显示,锚拉管中部出现残余应力最大值,达到230MPa,锚拉管两端的的残余应力值较小;锚拉板关键点3和关键点6的应力比其他关键点的大,说明锚拉板与锚拉管焊接端部疲劳问题较其他位置突出,在设计中应予以足够重视。

In order to investigate the fatigue performance of anchor plate of long-span cable-stayed bridge under random vehicle loads, the software ANSYS is used to establish the whole finite element model of the Xigu Yellow River Bridge and the local finite element model of anchor plate, furthermore, the stress state and fatigue behavior of the anchor plate under random vehicle loading are analyzed and studied. The results show that the stress at the end of the welding seam between anchor plate and anchor pipe is the largest, and the stress level of the other welds is low, in the meantime the stress concentration at the end of the weld is larger under the traveling load~ numerical analysis of the different paths shows that the maximum value of the residual stress is in the middle of the anchor pipe which is up to 230MPa, and the residual stress is small at both ends of the anchor pipe l the value of key point three and key point six of anchor plate is bigger than those of other key points, which indicates that the fatigue problem of welding end of anchor plate and anchor pipe is more prominent than others.