中文摘要：

以港珠澳大桥正交异性钢桥面为例，采用足尺模型试验和仿真分析，研究热点应力法在正交异性钢桥面板这类受力复杂结构疲劳强度评定的合理性与准确性，并结合其他足尺模型试验加以验证。研究结果表明：采用热点应力法评价复杂应力状态下疲劳细节结果离散性相比名义应力法而言显著降低；热点应力法考虑了各构造参数的影响，相比名义应力法，疲劳细节强度等级明显减少；对于U肋与横肋的连接焊缝这一典型的疲劳易损部位而言，可采用对应200×10^4次常幅疲劳循环的疲劳应力强度为90MPa的S-N曲线进行其疲劳性能评价。

英文摘要：

Full-sale experiment and simulation analysis on HongKong-Zhuhai-Macao bridge were conducted to find out whether hot spot stress method was suitable for fatigue assessment of orthotropic steel bridge deck, which was under complex stress, and to verify the results combined with other full-scale models. The results indicate that the discreteness of the fatigue results obtained with hot spot stress method is less than that with nominal stress method under complex stress; compared with nominal stress method, fatigue detail grade based on hot spot stress method is significantly decreased, since in which the effects of each structure parameter are taken into account. For the diaphragm-to-rib weld which is the typical vulnerable fatigue detail, S-N curve with fatigue strength of 90 MPa at Nc = 2 million cycles can be used to assess fatigue properties of diaphragm-to-rib weld.