Research on Measuring Point Arrangement for Modal Testing of Simply Supported Girder Bridges
The Load Test Methods for Highway Bridge only stipulates the minimum measurement point arrangement during modal testing of the bridge,which will lead to the underutilization of modal test data in the operation and maintenance of bridges.In order to reveal the relationship between bridge damage and modal test data,based on the basic theories of structural dynamics and damage mechanics,this study takes simply supported beam bridges as the research object and constructs damage identification indexes based on modal flexibility matrix,such as modal flexibility curvature,modal flexibility difference curvature,modal flexibility curvature difference and modal flexibility mean curvature difference rate of change.On this basis,the layout of the vibration pickup during the modal test and the order of the modal data on the identification effect are studied.The results show that:during the modal test,the modal data obtained by the vibration pickups arranged according to the main beam 16 equal distribution can better complete the damage identification of the structure;the modal flexibility curvature difference should be used as the identification index;the impact of higher order modal data on the damage identification is not obvious.The structural damage can be well identified by using the identification index of the first order modal test data components for the simply supported girder bridges.
damage identificationmodal testmeasuring point arrangement
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