Wide span rail traffic bridge damnification recognition method

Abstract

The invention relates to a large span rail traffic bridge damage recognition method, including the steps:(1) a sensor is arranged on the bridge which will be examined, the dynamic response signal of a large span rail traffic bridge is measured and is driven by that when a rail vehicle crosses the large span bridge, the signal on the sensor is red by a computer; (2) the benchmark bridge numerical model and the rail vehicle numerical model of the bridge are established; (3) a coupled mechanical analysis system comprising the benchmark bridge numerical model and the rail vehicle numerical model is initialized, an explicit integral method is used to solve the system, the simulated dynamic response signal of the benchmark bridge numerical model on a relative position is red according to the installment position of the sensor; (4) the energy spectrums of the dynamic response signal obtained by monitoring and the simulated dynamic response signal obtained by numerical simulation calculation of the bridge are solved by a multi-scale wavelet packet analysis method, and a damage recognition is carried on by recognizing index. The invention increases the precision of the bridge damage recognition, and the normal use of the bridge structure can not be affected.

Description

technical field [0001] The invention relates to a bridge detection method in the technical field of metrology, in particular to a damage identification method for a large-span rail transit bridge. Background technique [0002] With the advancement of science and technology and the growth of transportation demand, many rail transit bridges or long-span bridges for both road and rail transit (such as: Wuhan Yangtze River Bridge, Nanjing Yangtze River Bridge, Shanghai "Minpu Second Bridge" under construction) has been or will be completed. During the use of these bridges, they are constantly eroded by external environments such as temperature changes, strong winds, long-term repeated effects of vehicle loads, vehicle impacts, and natural disasters such as earthquakes and floods. With the increase of the service life, the structural materials continue to age and the fatigue effect continues to increase, resulting in different degrees of natural cumulative damage and sudden dama...

AI Technical Summary

Problems solved by technology

However, when domestic and foreign experts use vehicle-bridge coupled vibration analysis to identify bridge damage, the excitation of the bridge uses moving loads instead of moving vehicles, thus ignoring the impact of vehicle inertia on the bridge; in addition, for rail transit bridges, if Using a single moving load to replace complex multi-degree-of-freedom excitation loads such as trains, subways, and light rails cannot reflect the real working conditions, and will inevitably cause large errors in the damage identification process of such bridges

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