CN-115544758-B - Method for calculating equivalent stress of framework by eliminating large impact interference of wheel track

CN115544758BCN 115544758 BCN115544758 BCN 115544758BCN-115544758-B

Abstract

The invention discloses a method for eliminating large impact interference of wheel tracks and calculating equivalent stress of a framework, relates to the field of bogie systems of high-speed motor train units, and solves the problems that an existing equivalent stress calculating method cannot guide line maintenance, test signals of large impact interference of the wheel tracks are included in data of actual line tests and cannot be eliminated. According to the method, the large impact equivalent stress amplitude of the frame is calculated by eliminating the large impact interference of the wheel track, the state of a maintenance line is evaluated, and the actual equivalent stress of the frame under the condition of no large impact is predicted. Reasonable line maintenance standards are formulated, so that the structural strength of the bogie frame in the use process meets the requirements, and the bogie frame is not damaged.

Inventors

LI ZHONG
CUI LITONG
LIU CHUANG

Assignees

中车长春轨道客车股份有限公司

Dates

Publication Date: 20260512
Application Date: 20220929

Claims (4)

1. A method for eliminating large impact interference of wheel tracks and calculating equivalent stress of a framework is characterized by comprising the following steps: step one, collecting measured data, calculating the kurtosis value of a measured signal, and analyzing whether a large impact signal exists in the signal; Counting the large impact points, judging whether the number and the amplitude of the impact points meet the requirements, if so, executing the fourth step, otherwise, executing the third step; Step three, carrying out delay correlation analysis on the vibration acceleration of the axle box and the vehicle speed as the basis and the stress of the framework, verifying the positions of the impact points, and then eliminating the impact points of all periods respectively to meet the requirements directly, and executing the step four; and fourthly, performing equivalent stress calculation on the stress time domain signals after elimination, comparing the equivalent stress before and after elimination, and outputting a report by using life and kurtosis indexes.
2. The method for calculating equivalent stress of a frame by eliminating large impact interference of a wheel track according to claim 1, wherein in the first step, the collected actual measurement data comprises actual measurement data collection of vehicle speed, axle box vibration and frame stress by adopting a sensor, an acceleration sensor and a strain gauge.
3. The method for calculating equivalent stress of a frame by eliminating large impact interference of a wheel track according to claim 1, wherein in the second step, the large impact ratio of the frame stress data and the axle box vibration acceleration data is calculated, whether the large impact meets the requirement is judged, the impact acceleration amplitude of the axle box vibration acceleration is smaller than or equal to 70g, and the time occupied by the impact with the axle box acceleration amplitude smaller than 70g is smaller than the speed measurement time in a non-zero state of 3 parts per million.
4. The method for eliminating the large impact interference of the wheel track to calculate the equivalent stress of the framework according to claim 1, wherein the specific process of the third step is as follows: calculating delay time through delay correlation analysis according to the vibration acceleration of the axle box and the stress of the framework, and determining the time of a strain impact point and the position of the strain impact point in test data according to the speed of the vehicle; The impact point position in all periods is eliminated from the velocity, strain and vibration acceleration signals.

Description

Method for calculating equivalent stress of framework by eliminating large impact interference of wheel track Technical Field The invention relates to the field of high-speed motor train unit bogie systems, in particular to a method for eliminating large impact interference of wheel tracks and calculating equivalent stress of a framework. Background With the rapid development of the rail transit industry, higher requirements are put on rail transit equipment. The running part of the railway vehicle is taken as the most important part for influencing the safety of the railway vehicle, and the safety of the running part of the railway vehicle is particularly important. The bogie frame is used as a bridge for supporting and connecting other parts of the running part, and the service life of the bogie frame is always an important subject in the rail traffic industry. At present, the bogie frame of the railway vehicle can evaluate the structural strength of the newly designed bogie frame by using various means such as simulation analysis, bench test, line test and the like before the railway vehicle bogie frame is used in a offline manner, so that the structural strength of the bogie frame meets the requirement in the use process, the bogie frame is not damaged, the driving safety is influenced, and life and property loss is caused. In a line test, the evaluation method of the equivalent stress is a more reasonable evaluation method commonly adopted in the rail transit industry. Although the bogie frame at the beginning of design can be put into use only by meeting strict inspection flow and strict test conditions, in the practical bogie use process, the problem that the frame has cracks or short life expectancy is still caused by different types of reasons, and the problems all cause the equivalent stress index to exceed the standard. Of which wheel rail impact is the most important cause of equivalent stress overscaling. In order to extend the life of the frame, it is sometimes unavoidable to trim the line. At this time, the measured data needs to be analyzed to evaluate the line trimming standard. However, the data of the actual line test is a test signal containing the large impact disturbance of the wheel track, and a method is needed to evaluate the equivalent stress of the framework under the condition of no large impact of the wheel track. At present, the conventional equivalent stress calculation application of the measured line is very common, but an equivalent stress calculation method in the field of eliminating the measured data interference is not available. As shown in FIG. 1, the conventional equivalent stress evaluation method mainly performs rain flow counting calculation after removing interference filtering and trend filtering of an electrical system according to actual measured stress data, then classifies the rain flow counting result for computer calculation, and then calculates the equivalent stress according to the actual S-N curve of the material. The traditional equivalent stress calculation method can calculate the equivalent stress of the framework in the actual track state, but the equivalent stress in the actual track state does not guide line maintenance, and a method for calculating the equivalent stress of the framework in different line sign states is required to be sought, so that the method for calculating the equivalent stress of the framework by eliminating the large impact interference of the wheel track can meet the requirements. Disclosure of Invention The invention provides a method for eliminating equivalent stress of a wheel-rail large impact interference calculation framework, which aims to solve the problems that the existing equivalent stress calculation method cannot guide line maintenance, and the actual line test data comprise test signals of the wheel-rail large impact interference and cannot be eliminated. A method for eliminating large impact interference of wheel tracks to calculate equivalent stress of a framework is realized by the following steps: step one, collecting measured data, calculating the kurtosis value of a measured signal, and analyzing whether a large impact signal exists in the signal; Counting the large impact points, judging whether the number and the amplitude of the impact points meet the requirements, if so, executing the fourth step, otherwise, executing the third step; Step three, carrying out delay correlation analysis on the vibration acceleration of the axle box and the vehicle speed as the basis and the stress of the framework, verifying the positions of the impact points, and then eliminating the impact points of all periods respectively to meet the requirements directly, and executing the step four; and fourthly, performing equivalent stress calculation on the stress time domain signals after elimination, comparing the equivalent stress before and after elimination, and outputting a report by using life and kurtosis indexes. The