Wang Zhiyu, Shi Yunzhong, You Xiang, Jiang Ruijuan, Gai Weiming
Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, B1-B2, 10th Floor, Shunji Building, St No. 252, Chengdu 610065, China.
Sichuan Provincial Key Laboratory of Failure Mechanics and Engineering Disaster Prevention & Mitigation, Sichuan University, B1-B2, 10th Floor, Shunji Building, St No. 252, Chengdu 610065, China.
Materials (Basel). 2020 Dec 24;14(1):38. doi: 10.3390/ma14010038.
The aim of this study is to find out the degradation of dynamic behaviour of bridge girders with trapezoidal profiled webs when subjected to different vehicle moving loads. Finite element modelling based parametric analysis is demonstrated to be desirable in capturing the dynamic deflection and stress state of critical structural details of girders. The model is validated in the modal analysis through a comparison with theoretical eigenfrequencies. The vibration characteristics are shown to be significantly affected by the corrugation details. The structural service life results of analysed bridge girders are in close agreement with experimental data. It is shown that the dynamic nodal velocity and deflection of analysed bridge girders are greatly affected by the magnitude of the load corresponding to the overload of the vehicle in contrast to the vehicle travel speed. Similar observations can be made for the fatigue life prediction analysis related to the crack initiation when unfavourable effects of the overload vehicle are concerned. Presented analytical results using a fracture mechanics approach could be taken as a good basis for the service life assessment of related bridges with the desired level of performance or functionality.
本研究的目的是找出梯形腹板桥梁大梁在承受不同车辆移动荷载时其动力性能的退化情况。基于有限元建模的参数分析被证明对于捕捉大梁关键结构细节的动态挠度和应力状态是可取的。通过与理论固有频率进行比较，该模型在模态分析中得到了验证。结果表明，振动特性受波纹细节的影响显著。分析的桥梁大梁的结构使用寿命结果与实验数据密切吻合。结果表明，与车辆行驶速度相比，分析的桥梁大梁的动态节点速度和挠度受对应于车辆超载的荷载大小的影响很大。当考虑超载车辆的不利影响时，对于与裂纹萌生相关的疲劳寿命预测分析也可得出类似的结论。使用断裂力学方法给出的分析结果可为相关桥梁在期望的性能或功能水平下的使用寿命评估提供良好的基础。
