Random recognition method for bridge floor moving vehicle loads

Abstract

The invention discloses a random recognition method for bridge floor moving vehicle loads. The method comprises the following steps that (1) raster sensors, strain sensors and acceleration sensors are arranged on a bridge floor to obtain running speeds of moving vehicles and the dynamic strain and acceleration responses of a bridge under the action of the moving vehicle loads; (2) an accurate structural finite element model is established for a bridge structure, model condensation is carried out, and the freedom degree of the bridge model after the model condensation is made to be matched with dynamic strain signal measuring positions; (3) the deterministic components of bridge random dynamic displacement, speed and acceleration are obtained by utilizing a KL decomposition technique on the basis of actual measurement dynamic strain response samples; (4) the deterministic components random moving vehicle loads on the bridge floor are recognized by directly adopting a sample matrix inversion and a Tikhonov regularization method; (5) the statistical properties, average time history and variance, of the random moving vehicle loads are obtained.

Description

technical field [0001] The invention belongs to the technical field of random dynamic load identification, and relates to a random identification method of moving vehicle loads on a bridge deck based on KL decomposition technology. Background technique [0002] The load of moving vehicles is one of the main types of loads on bridges. Accurately obtaining the load information of moving vehicles on bridges is very important for life prediction and state assessment of bridge structures. The traditional parking weighing method is time-consuming and laborious, and can only obtain the axle load information of the vehicle; the mobile weighing system can obtain the equivalent axle load information of the vehicle when the vehicle passes by, which improves the weighing efficiency, but can only obtain the equivalent static axle load . Studies have shown that the dynamic load of the same vehicle can damage bridges 2 to 4 times that of the static axle load. Therefore, it is of great val...

AI Technical Summary

Problems solved by technology

Although this type of method can obtain the moving load information of the bridge deck more accurately based on the single-measured bridge dynamic response data, it cannot consider the randomness of the excitation load when only relying on the single-measured response data to identify the moving dynamic load.

In fact, due to the unevenness of the road surface, the exciting force of the moving wheels on the bridge surface itself presents a certain "randomness". When it acts on the bridge structure, the dynamic response of the bridge will also present "randomness"; The measured dynamic response of the bridge can only be one sample of the random dynamic response information of the structure, and the dynamic load information obtained by using the deterministic moving load identification method based on a certain response sample can only partially reflect the random dynamic load excitation; The errors contained in the secondary dynamic response measurement are also taken as part of the "true response" in the deterministic moving load identification, causing deviations in the load identification results

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