Method for identifying modal characteristics of railway track structure

Abstract

The invention discloses a method for identifying the modal characteristics of a railway track structure. The method includes the following steps: arranging multiple sensors on a railway track, and taking the position of each sensor as a measuring point; selecting partial or total measuring points as incentive points knocked by a hammer; recording the response situations of the measuring points through the multiple sensors when the hammer knocks the incentive points so that the modal characteristics of a railway track structure can be analyzed; and selecting multiple fixed fastener spacing on the railway track as test ranges used for arranging the measuring points, wherein the test ranges are fixed, and the positions of the measuring points are fixed. The method is large in test frequency range and god in test quality; the vertical and horizontal modal characteristics of steel rails can be effectively identified; the method is high in test efficiency and can accomplish operation withina maintenance window period; and the method is good in contrast between test data of multiple tests, so that effective contrast analysis can be performed on the test data at different time and different places.

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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