A method for identifying the modal characteristics of railway track structures

Abstract

A method for identifying the modal characteristics of a railway track structure, comprising: arranging a plurality of sensors on the railway track, and the position of each sensor is used as a measuring point; selecting part or all of the measuring points as the excitation points for hammering; When the hammer strikes the excitation point, the response of the measuring point is recorded by the plurality of sensors, and then used to analyze the modal characteristics of the railway track structure; A plurality of fastener intervals are used as a test range for arranging the measuring points; the test range is fixed, and the position of the excitation point is fixed. The invention has a wide range of test frequency and good test quality, can effectively identify the vertical and transverse modal characteristics of the rail, has high test efficiency, can complete the work within the maintenance window period, and has good comparison between test data of multiple tests. Effective comparison and analysis of test data at different times and locations can be carried out.

Description

technical field [0001] The invention relates to the technical field of rail transportation, in particular to a method for identifying the modal characteristics of a railway track structure. Background technique [0002] The rail mode is the embodiment of the comprehensive modal characteristics of the railway track structure, which reflects the inherent dynamic characteristics of the track structure, and is useful for analyzing the dynamic characteristics of the track structure, optimizing the design parameters of the track structure and components, and revealing the dynamic damage mechanism of the track structure and components, etc. Therefore, the modal feature identification method and system of the track structure are very important. The modal feature identification of the rail is divided into two types: the vertical and transverse modal feature identification of the rail, both of which adopt the hammer test method. The existing rail The modal feature identification metho...

AI Technical Summary

Problems solved by technology

[0003] First of all, from the perspective of the vertical modal measuring point layout of the rail, the range L of the measuring point layout is not clear, and it is randomly set based on experience during the test. If the measuring point range is small, the low-order modal characteristics of the rail cannot be effectively tested. If the measuring point range is too large If the value is too large, the test efficiency will be greatly reduced; the location and quantity of the hammer excitation points are not clear, and they are set randomly based on experience during the test. If the excitation points are too few or too concentrated, the data will be poor and the modal characteristics cannot be obtained effectively; if the excitation points If there are too many, the test efficiency will also be greatly reduced; the measuring points are arranged at equal intervals, the distance between the measuring points is 0.5 fasteners, and the effective range of the vertical test modal frequency is 0-1500Hz. Because there are not enough measuring points, it cannot be tested Higher frequency modal characteristics; due to the lack of clear measurement point layout range L, excitation point location and quantity, the comparability between test data is poor, and there is no comparability between test results in multiple test cycles. Detected changes where it is not possible to determine whether the structure itself has changed or is due to differences between the stimulus points for multiple tests

[0004] Furthermore, from the perspective of the layout of the rail transverse mode measuring points, the range L of the measuring point layout is not clear, and the test is randomly set based on experience, which is greatly influenced by the experimenter. If the range of measuring points is small, the low-order mode of the rail cannot be effectively tested. If the range of measuring points is too large, the test efficiency will be greatly reduced. In the online test, the test window period is short, and it is very likely that the test cannot be completed at one time. It may be necessary to repeat the test for many times. The location and quantity of the hammer excitation points are not clear, and they are set randomly based on experience during the test. If the excitation points are too few or too concentrated, the data will be poor and the modal characteristics cannot be obtained effectively; if there are too many excitation points, the same It will greatly reduce the test efficiency; the measuring points are arranged at equal intervals, the distance between the measuring points is 0.5 fasteners, and the effective range of the transverse test modal frequency is 0-600Hz, and the modal characteristics of higher frequencies cannot be tested; because the measuring points are not clear Layout range L, location and quantity of excitation points, so the comparability between test data is poor

[0005] To sum up, the existing test methods have shortcomings such as low test efficiency, poor test quality, poor test data contrast and small test frequency range.

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