Dynamic deflection monitoring method for 32-meter high-speed rail standard simply supported beam

Abstract

A dynamic deflection monitoring method for a 32-meter high-speed rail standard simply supported beam relates to a dynamic deflection monitoring method. The method comprises: extracting displacement and strain influence lines of the key measuring points based on Ansys finite element numerical simulation; establishing a UM multi-body dynamic model to extract a displacement and strain time travel curve of the key measuring points; based on unbalance load distribution of train loads of two lanes of the bridge and sparse distribution of external loads of generalized nodes of the bridge floor, adopting l1 regularization sparse reconstruction by the strain influence line to invert external loads of equivalent generalized nodes, reconstructing a full-bridge displacement field by the displacement influence line, and solving the external loads of the equivalent generalized nodes to determine optimal regularization parameters; and calculating the relative error percentage between the reconstruction and the theoretical or actually measured time-history displacement vector to verify the accuracy. The equivalent generalized node external load is reconstructed by adopting an l1 regularization sparse reconstruction theory based on a strain influence line of a bridge key measuring point, and the problem that a train does not conform to a plane section hypothesis under the unbalance loading bending-torsion coupling action is solved.

Description

technical field [0001] The invention relates to a dynamic deflection monitoring method, in particular to a dynamic deflection monitoring method of a 32-meter high-speed rail standard simply supported beam, and belongs to the technical field of high-speed rail bridge health monitoring. Background technique [0002] As of 2020, the total mileage of high-speed railways in my country will exceed 35,000 kilometers, and the total number of high-speed railway bridges will reach more than 30,000, with a total mileage of more than 16,000 kilometers. China is the world's largest high-speed railway bridge country. As the throat and main road of high-speed railway traffic, the safety of high-speed rail bridges directly affects the normal operation of traffic and the development of the national economy. However, more than 85% of the high-speed rail bridges with such a huge volume are prestressed concrete simply supported box girder bridges with equal span layout. Due to the influence of ...

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Problems solved by technology

However, the current analysis methods all simplify the bridge girder body to an Euler-Bernoulli beam, assuming that the deformation of the bridge section conforms to the assumption of a plane section. For the characteristics of the partial load distribution of the train load on the 32-meter standard beam of the high-speed railway, the bending-torsion The traditional "strain-dynamic deflection" conversion equation cannot be established under the coupling effect

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