基于热点应力的钢桥面典型构造细节疲劳分析

正交异性钢桥面具有轻质、高性能、施工便捷等应用优势，但其构造复杂且多采用焊接工艺，在反复交变车辆轮载作用下疲劳开裂问题突出。其中，顶板与纵肋连接焊缝(简称顶板-纵肋焊缝)和纵肋与橫肋连接焊缝(简称纵肋-橫肋焊缝)是两类最突出和最具代表性的构造细节。本文采用名义应力法和三种常用热点应力法，在充分考虑交通量对荷载修正的基础上，对上述两类钢桥面典型构造细节开展了精细化有限元分析，确定疲劳应力幅，并进行疲劳检算。通过分析和对比各疲劳评价方法，提出适用于各类构造细节的计算方法。分析结果表明，分析顶板-纵肋构造细节和纵肋-橫肋焊趾截止处纵肋腹板竖向开裂推荐采用表面线性外推方法(Linear Surface Extropolation, LSE)方法，分析纵肋-橫肋焊趾截止处纵肋腹板横向开裂推荐采用Dong方法。研究结果可为正交异性钢桥面的评估、设计和应用提供参考。

Fatigue Analysis of Structure Typical Details in Steel Decks Based on hot spot stress method

Orthotropic steel decks (OSDs) show advantages such as light-weight, high performance and rapid construction. However, the OSD demonstrates notable fatigue cracking under the direct impact of vehicles, because of its massive welding works and complicated configurations. The deck-to-rib weld and the rib-to-beam weld are the two most outstanding and typical structural details. Considering the load correction by the traffic volume adequately, this paper analyzes the two typical details of OSDs with detailed finite element, in order to determine the fatigue stress range and perform fatigue checking. Different calculation methods are proposed according to the different structural details, through analyzing and comparing detail types of fatigue evaluation approaches. The results recommends the LSE method for the deck-rib weld and vertical rib-beam weld, and Dong method for the transverse rib-beam weld. The research output can offer references for the evaluation, design and application of OSDs.