两种人行桥的人致振动性能的仿真与比较

Simulation and Comparison of Two Different Pedestrian Bridges in Vibration Performance Under Crowd Load

为了验证以钢管混凝土材料代替传统钢材用于人行桥主梁能否进一步改善钢结构人行桥的人致振动性能,以现有的一座由H型钢梁和钢筋混凝土板组成的简支单跨人行桥为原型,按照刚度等效原则将钢梁桥的主梁替换为钢管混凝土梁,然后运用有限元软件对两种桥分别建模,并对模型进行人群荷载作用下的时程分析,以峰值加速度和均方根加速度为指标比较两者的振动性能。结果显示钢管混凝土梁人行桥的振动响应加速度最大值和均方根值都比钢梁桥的小的多。可见以矩形钢管混凝土构件为梁的人行桥比钢梁人行桥具有更优越的人致振动性能。

To verify whether the pedestrian bridge with steel beams have better vibration performance under crowd load in replacing the steel beams with concrete -filled rectangular steel tube beams, this paper chose a simply sup- ported pedestrian bridge with single span which was built with H - Section Steel Beams and reinforced concrete slabs. Then the H - Section Steel Beams was changed into concrete - filled rectangular steel tube beams based on equivalent stiffness principle. The two bridges were modeled by ANSYS and brought to make time - history analysis under crowd load. Their vibration performances were compared with maximum and mean square root acceleration. The results show that the pedestrian bridge with concrete -filled rectangular steel tube beams has much lower acceleration maxi- mum and mean Square root than that with steel beams, which verifies the pedestrian bridge with concrete - filled rec- tangular steel tube beams has better vibration performance under crowd load than that with steel beams.