A Dynamic Deflection Monitoring Method of Standard Simply Supported Beams for 32-meter High-speed Railway

Abstract

A dynamic deflection monitoring method of a standard simply supported beam of a 32-meter high-speed railway relates to a dynamic deflection monitoring method. The displacement and strain influence lines of key measuring points are extracted based on Ansys finite element numerical simulation; the UM multi-body dynamics model is established to extract the displacement and strain time-history curves of key measuring points; The external loads are sparsely distributed, the strain influence line adopts l1 regularization sparse reconstruction to invert the equivalent generalized nodal external load, and the displacement influence line reconstructs the displacement field of the whole bridge, and the equivalent generalized nodal external load is calculated to determine the optimal regularization parameter; The relative error percentage between the reconstruction and the theoretical or measured time-history displacement vector verifies the accuracy. Based on the strain influence line of the key measuring points of the bridge, the equivalent generalized out-of-node load is reconstructed by using the l1-regularized sparse reconstruction theory to solve the problem that the train does not conform to the assumption of plane section under the eccentric load bending-torsional coupling.

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 ...

AI Technical Summary

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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