Fatigue assessment of orthotropic steel bridge decks based on strain monitoring data
Fatigue assessment of orthotropic steel bridge decks based on strain monitoring data
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DOI：
10.1016/j.engstruct.2020.111437
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发表时间：
2021-02-01
影响因子：
5.5
通讯作者：
Peng, Xi
中科院分区：
文献类型：
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作者：
Di, Jin;Ruan, Xiaozheng;Peng, Xi
正交异性钢桥面板在长期高循环应力作用下，由于不可避免的制造缺陷，容易产生疲劳裂纹。基于局部应变监测，研究了实际交通流条件下OSD典型连接节点的应力行为，包括桥面-肋连接节点、肋-横隔板连接节点和横隔板开孔节点。根据两周热点应力监测数据对OSD的疲劳性能进行了评价。结果表明，在轮载作用下，各典型连接节点的局部效应均较显著，且各节点的横向影响范围均在两条纵肋内。疲劳易损部位的应力水平较高，膜片开孔部位的应力峰值达到246 MPa。在不考虑交通量变化的情况下，所监测的正交异性钢桥面典型连接细节的疲劳寿命均小于100年，应采取紧急措施提高疲劳性能。有限元分析结果表明，超高性能混凝土复合路面系统可以有效降低结构细节的疲劳应力幅。桥面板与肋连接细节的应力改善效果最为明显，桥面板焊趾细节影响线峰值可降低80-90%，可有效消除OSD疲劳开裂风险。
Orthotropic steel decks (OSDs) are prone to fatigue cracks due to long-term wheel loading with high cyclic stress and unavoidable manufacturing defects. In this study, the stress behavior of the typical connection details in OSD under actual traffic flows is investigated based on local strain monitoring, including the deck-to-rib connection detail, the rib-to-diaphragm connection detail, and the cut-outs detail of the diaphragm. The fatigue performance of the OSD was evaluated based on two weeks monitoring data of hot spot stress. Result shows that the local effect of all the typical connection details is significant under wheel load, and the transverse influence area of each detail is within two longitudinal ribs. The stress level of fatigue vulnerable details was high, the peak value of the cut-outs detail of the diaphragm reached 246 MPa. The fatigue life of the typical connection details of the monitored orthotropic steel deck were all less than 100 years without considering change in the traffic volume, urgent measures should be implemented to improve the fatigue performance. The finite element analysis result shows that an ultra-high performance concrete composite pavement system can effectively reduce the fatigue stress amplitude of structural details. The stress improvement effect of the deck-to-rib connection details was the most obvious, the peak value of the influence line of the weld toe detail of the deck can be reduced to 80-90%, which can effectively eliminate the risk of fatigue cracking of the OSD.