Abstract Orthotropic steel decks (OSDs) are widely used in long span steel bridges owing to their outstanding structural characteristics and lightweight; however, the fatigue resistance of OSDs is still a prominent problem of such deck structures. Ultra-High-Performance Concrete (UHPC) has been recently employed in orthotropic steel decks to enhance their structural behavior and extend their fatigue life. In this paper, experimental work has been carried out to investigate the effect of employing UHPC overlay on the hot spot stresses at fatigue prone details of OSDs. Three full scale rib-to-deck-to-floor beam (RDF) welded connections were fabricated and tested. One centric wheel load was applied; so that, the effect of in-plane and out-of-plane distortions of floor beam web can be considered. In parallel with the experimental program, a finite element (FE) analysis was also performed. Upon validation of FE models against experimental results, a parametric study was carried out to study the effect of key structural parameters that primarily influence the hot spot stresses. Experimental results indicated that, the stresses around floor beam cut-out were slightly higher than the hot spot stresses at considered locations on U-rib due to in-plane and out-of-plane distortions of the floor beam web under centric loading. The application of 60 mm UHPC layer effectively reduced the hot spot stresses by 26–83% at the considered locations of the test specimens. Results of parametric study indicated that, increasing UHPC layer thickness significantly enhanced the stiffness of the bridge deck and therefore effectively reduced the hot spot stresses at considered spots. On the other hand, the effect of increasing UHPC elastic modulus slightly influenced the hot spot stresses at considered locations and its effect is deemed neglectable.

中文翻译：

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使用 UHPC 层降低正交异性钢桥面板焊接连接中的热点应力：实验和数值研究

摘要 正交异性钢桥面板（OSDs）以其突出的结构特性和轻量化的特点在大跨度钢桥中得到广泛应用。然而，OSD 的抗疲劳性仍然是此类甲板结构的一个突出问题。超高性能混凝土 (UHPC) 最近已用于正交各向异性钢甲板，以增强其结构性能并延长其疲劳寿命。在本文中，已经进行了实验工作来研究使用 UHPC 叠加对 OSD 易疲劳细节处的热点应力的影响。制造并测试了三个全尺寸肋到甲板到地板梁 (RDF) 的焊接连接。施加了一个中心轮载荷；因此，可以考虑楼板梁腹板平面内和平面外变形的影响。与实验计划并行，还进行了有限元 (FE) 分析。根据实验结果验证有限元模型后，进行了参数研究以研究主要影响热点应力的关键结构参数的影响。实验结果表明，由于中心荷载作用下地板梁腹板的平面内和平面外变形，地板梁切口周围的应力略高于 U 形肋上考虑位置的热点应力。60 mm UHPC 层的应用有效地将试样所考虑位置处的热点应力降低了 26-83%。参数研究结果表明，增加 UHPC 层厚度显着提高了桥面板的刚度，从而有效地降低了考虑点的热点应力。另一方面，