基于测点位移差的中、下承式拱桥吊杆损伤识别

根据摄动有限元法原理,提出了基于测点间位移差的变化进行吊杆损伤识别的方法。进行吊杆损伤识别时,先测试吊杆节点间的高程差,并减去损伤前相同2个节点竖向位移差,得到吊杆损伤后2个节点竖向位移差的变化;再通过节点竖向位移差的变化构成吊杆损伤识别方程;当损伤识别初定方程和确定方程识别结果基本一致时,即判定吊杆发生损伤,并取2个方程所得吊杆损伤程度均值作为损伤程度;最后,以京珠高速郑州黄河二桥主桥为例验证了该方法。结果表明：采用该方法进行吊杆损伤识别,识别结果精度较高,即使对于小程度损伤也可识别,且测量误差对识别结果影响较小。

Damage Identification for Suspender of Through and Half-through Arch Bridges Based on Displacement Differences of Monitoring Points

According to the matrix perturbation theory,a new damage detection method for suspender based on displacement differences of monitoring points was proposed.When suspender damage was detected,differences of elevation of suspender nodes were tested firstly,then,authors subtracted vertical displacement differences of the same two nodes of undamaged bridge to get the change of vertical displacement differences caused by the suspender damage.The damage detection equations for suspender were got from the change of vertical displacement differences of suspender nodes.When the identified results from damage pre-determination and determination equations were nearly same,the suspender damage was determined,and the mean value of suspender damage degree was regarded as the damage extent.Main bridge of the second Zhengzhou Yellow River Bridge on Beijing-Zhuhai Expressway was taken as an example to verify this method.The numerical results show that the precision of this method of damage identification for suspender of through and half-through arch bridges is high even if the damage extent is little.The measurement error has a little influence on the damage identification results.