基于模态参数的铁路站台张弦结构损伤识别

Damage Identification of Beam String Structure on the Railway Platform Based on Modal Parameter

研究目的:随着铁路客运站规模的不断扩大,为使站台的使用空间增加,我国很多铁路站台使用无站台柱式的大跨度雨棚,张弦结构因具有优异的受力性能而在无站台柱式雨棚中有着广阔的应用前景。因此,对服役中的铁路客运站张弦结构损伤状况进行识别、预测损伤后的极限承载力具有十分重要的意义。研究结论:(1)建议以频率变化率FRC_i和正则化频率变化率NFRC_i作为站台张弦结构体系的损伤识别参数;(2)建议以NFRC_1作为张弦结构的桁架损伤定位参数,以NFRC_2作为撑杆和拉索损伤定位参数,以FRC_3作为预应力损失识别参数;(3)给出了不同部位损伤后结构模态参数FRC_i与相对极限承载力k之间的关系;(4)本研究结果可为铁路站台张弦结构的损伤识别和极限承载力评估提供参考。

Research purposes： With the development of railway passenger station in our country, the long - span canopy without platform column was used in many railway platforms in order to increase the space of platform. The beam string structure （BSS） possesses excellent structural performance and has broad application prospects in canopy without platform column. Therefore, it is very important to identify the ultimate carrying capacity of BSS after the damage. damage of BSS on railway platform, and to predict the Research conclusions： （ 1 ） Frequency rate - of - change （FRC） and normalized frequency rate - of - change （NFRC） were suggested as the parameters of damage identification for BSS on railway platform. （2） It is suggested that NFRCj as parameter for truss damage location, NFRC2 as parameter for strut and string damage location, and FRC3 as parameter for prestressing loss identification. （3） The relationships between modal parameter FRCi and relative ultimate carrying capacity k were suggested. （4） The study in this paper can provide a reference for the damage identification and assessment of ultimate carrying capacity for BSS on railway platform.