CN116542042A - Description method and test method for steel rail welded joint - Google Patents

Abstract

The application discloses a description method and a test method of a steel rail welding joint, and belongs to the technical field of rail transit. The method mainly comprises the following steps: obtaining measured data of the geometric shape of the steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the measured data; according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments; performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function. The method solves the problem that the description of the existing steel rail welding joint is inaccurate, so that the wheel rail high-frequency impact force identification in the simulation analysis is inaccurate.

Description

Description method and test method for steel rail welded joint

Technical Field

The application relates to the technical field of rail transit, in particular to a description method and a test method of a steel rail welding joint.

Background

In order to eliminate the influence of interaction between wheel and rail caused by rail joints on a wheel and rail coupling power system, ultra-long welded seamless rails are commonly used in high-speed railways in China. However, due to the factors of the welding process level, the later maintenance and repair and the like, the phenomenon that the partial rail surface of the rail is short-wave and unsmooth in the rail welding area can be formed due to the fact that the partial rail surface is high and the rail welding joint is under the repeated action of the wheel rail contact force. Even when the magnitude of the rail weld joint irregularity is small, serious wheel-rail impact load is caused, which may cause damage to vehicle-rail system components such as rails, fastener systems, wheels and the like, and may pose a serious threat to the safety and riding comfort of train operation.

Therefore, accurately obtaining the wheel rail impact load under the rail welded joint irregularity is the basis for studying the damage to the vehicle-rail system components, and the premise of completing the study is to accurately describe the rail welded joint irregularity. The mathematical model of the unsmooth condition of the steel rail welding joint in the prior art has a certain difference with the actual unsmooth condition of the steel rail welding joint, and the problem can not be accurately reflected when the simulation test of the wheel rail impact load is carried out.

Disclosure of Invention

Aiming at the problem of inaccurate description of the steel rail welding joint in the prior art, the application mainly provides a description method and a test method of the steel rail welding joint.

In order to achieve the above object, a first technical solution adopted in the present application is: a method of describing a rail weld joint comprising: obtaining measured data of the geometric shape of the steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the measured data; according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments; performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

Optionally, segmenting the waveform according to the shape of the waveform to obtain a plurality of segments, including: the waveform is analyzed to obtain amplitude and wavelength reflecting the waveform shape, and the waveform is segmented according to the amplitude and wavelength to obtain a plurality of segments.

Optionally, according to the waveform shape, carrying out segmentation processing on the waveform to obtain a first segment and a third segment which are positioned at two ends of the waveform and a second segment which is positioned in the middle of the waveform; and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

Optionally, fitting the plurality of segments to obtain a corresponding parabolic function and cosine function includes: and determining the parabolic function and the cosine function by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, wherein the product between the train running speed and the time is the wavelength corresponding to the segment.

Optionally, performing product operation with the time and the first predetermined multiple and the magnitudes corresponding to the first segment and the third segment respectively to obtain a first product and a second product; dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient; subtracting the ratio between the time and the first quotient or the second quotient by using a preset value to obtain a first difference value and a second difference value; and describing a first segment of the fitted waveform shape using a ratio between the first product and a product of the first quotient and the first difference, and describing a third segment of the fitted waveform shape using a ratio between the second product and a product of the second quotient and the second difference.

The second technical scheme adopted by the application is as follows: a method of testing a rail welded joint comprising: carrying out wheel rail impact force numerical simulation analysis of the steel rail welding joint by utilizing a pre-obtained mathematical model; the obtaining process of the pre-obtained mathematical model comprises the following steps: obtaining measured data of the geometric shape of the steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the measured data; according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments; performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

Optionally, segmenting the waveform according to the shape of the waveform to obtain a plurality of segments, including: the waveform is analyzed to obtain amplitude and wavelength reflecting the waveform shape, and the waveform is segmented according to the amplitude and wavelength to obtain a plurality of segments.

Optionally, according to the waveform shape, carrying out segmentation processing on the waveform to obtain a first segment and a third segment which are positioned at two ends of the waveform and a second segment which is positioned in the middle of the waveform; and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

Optionally, fitting the plurality of segments to obtain a corresponding parabolic function and cosine function includes: and determining the parabolic function and the cosine function by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, wherein the product between the train running speed and the time is the wavelength corresponding to the segment.

Optionally, performing product operation with the time and the first predetermined multiple and the magnitudes corresponding to the first segment and the third segment respectively to obtain a first product and a second product; dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient; subtracting the ratio between the time and the first quotient or the second quotient by using a preset value to obtain a first difference value and a second difference value; and describing a first segment of the fitted waveform shape using a ratio between the first product and a product of the first quotient and the first difference, and describing a third segment of the fitted waveform shape using a ratio between the second product and a product of the second quotient and the second difference.

The beneficial effect that this application's technical scheme can reach is: the actual irregularity of the steel rail welded joint is described more accurately by accurately fitting the irregularity of the steel rail welded joint through the parabolic function and the cosine function, and the problem that the wheel rail high-frequency impact force identification in simulation analysis is inaccurate due to the inaccuracy of the description of the steel rail welded joint is solved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is a schematic view of one embodiment of a method of describing a rail weld joint of the present application;

FIG. 2 is a schematic illustration of a specific classification of rail weld irregularities of the present application;

FIG. 3 is a schematic illustration of the wheel rail impact load of the wheel of the present application as it passes over a rough rail;

FIG. 4 is a schematic illustration of the geometric description of the various models of the present application versus field test results for three types of weld irregularities;

FIG. 5 is a schematic illustration of simulation results of the wheel-rail vertical force time domain versus convex-A irregularity of the present application;

FIG. 6 is a schematic illustration of simulation results of the wheel-rail vertical force time domain versus convex-B irregularity of the present application;

FIG. 7 is a schematic illustration of simulation results of wheel-track vertical force time domain versus concave irregularity in the present application;

FIG. 8 is a schematic diagram of error analysis of simulation results and measured data of the wheel-rail vertical force time domain comparison of the present application;

FIG. 9 is a graph showing simulation results of wheel-rail vertical force frequency domain versus convex-A irregularity in the present application;

FIG. 10 is a graph of simulation results of wheel-rail vertical force frequency domain versus convex-B irregularity in the present application;

FIG. 11 is a graph showing simulation results of wheel-rail vertical force frequency domain versus concave irregularity in the present application.

Specific embodiments thereof have been shown by way of example in the drawings and will herein be described in more detail. These drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments.

Detailed Description

The preferred embodiments of the present application will be described in detail below with reference to the drawings so that the advantages and features of the present application can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present application.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

In the prior art, according to field actual measurement data at a rail welding joint, common irregularity conditions of the rail welding joint are divided into three types as shown in fig. 2, and description methods adopted for the three types of prior art are as follows:

1. the description is directly made using the measured data. Although the description method is accurate, the influence of each key parameter on the high-frequency impact force of the wheel track is difficult to analyze;

2. the cosine harmonic function model is fully utilized for description. The description method adopts a cosine function to describe the irregularity of the steel rail welding joint, and the formula is as follows:

wherein z0 (t) represents the vertical displacement caused by the welded joint of the steel rail; a and lambda respectively represent the amplitude and the wavelength of the steel rail welding joint; v is the train running speed and t is the time. The shape difference between the description method and the actual steel rail welding joint is large, and the wheel rail high-frequency impact force numerical simulation analysis of the shape of the steel rail welding joint is not facilitated.

3. The description is made using a complex cosine harmonic model. The description mode adopts two cosine function segments to describe the irregularity of the steel rail welding joint, wherein the description formulas of the irregularity of the three steel rails of the convex type-A, the convex type-B and the concave type in the figure 2 are as follows:

wherein a1 and a2 represent magnitudes corresponding to the first segment and the second segment, respectively; λ1 and λ2 represent the wavelengths corresponding to the first segment and the second segment, respectively. Although the description method is closer to the actual shape of the steel rail welding joint, the recognition force of the high-frequency impact load is poor when the wheel rail high-frequency impact force numerical simulation analysis is carried out, and the subsequent analysis is not convenient.

In summary, please propose a method, a device, a medium, a device, a program product and a method for testing a rail welded joint. Under the condition that the steel rail welded joint described by the mathematical model is closer to the real condition, the method simultaneously enables the test result of the wheel rail high-frequency impact force numerical simulation analysis by using the mathematical model to more intuitively reflect the problem, so that the problem analysis can be carried out better according to the test result.

The following describes the technical solution of the present application and how the technical solution of the present application solves the above technical problems in detail with specific embodiments. The specific embodiments described below may be combined with one another to form new embodiments. The same or similar ideas or processes described in one embodiment may not be repeated in certain other embodiments. Embodiments of the present application will be described below with reference to the accompanying drawings.

Fig. 1 shows an embodiment of a method of describing a rail welded joint according to the present application.

The method for describing the steel rail welding joint shown in fig. 1 comprises the following steps: step S101, obtaining actual measurement data of the geometric shape of the steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the actual measurement data;

step S102, carrying out segmentation processing on the waveform according to the waveform shape to obtain a plurality of segments;

step S103, performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and

and step S104, obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

In the specific embodiment, the geometric shape of the steel rail welding joint is described through a parabolic function and a cosine function, so that the obtained mathematical model can be better matched with the actual situation, the simulation error of the wheel-rail force response and test data in the time domain is smaller, and the wheel-rail force response in the frequency domain, particularly the high-frequency component of the wheel-rail force response, can be better reflected.

Specifically, as shown in the schematic diagram of specific classification of the rail welding irregularity in fig. 2, actual measurement data of the rail welding joint irregularity is obtained through in-situ testing, and a convex-a waveform shown in a diagram in fig. 2, a convex-B waveform shown in B diagram in fig. 2 and a concave waveform shown in c diagram in fig. 2 are obtained through actual measurement data processing, wherein the waveforms shown in fig. 2 are only schematic, and in actual situations, rail welding joint geometries of other shapes may exist. The male-a waveform, the male-B waveform, and the female waveform in fig. 2 are divided into three segments according to the shape of the waveform. Fitting the three segments to obtain corresponding parabolic functions and cosine functions, and further obtaining a mathematical model describing the geometric shape of the steel rail welding joint.

In the embodiment shown in fig. 1, the method for describing the rail welded joint includes step S101, obtaining measured data of the geometry of the rail welded joint, and obtaining a waveform reflecting the geometry of the rail welded joint according to the measured data. According to the embodiment, the waveform of the obtained geometric shape of the steel rail welding joint is enabled to be more close to the geometric shape of the actual steel rail welding joint, and the subsequent fitting result is enabled to be more accurate.

Specifically, testing is performed at the steel rail welding joint by using an instrument or manually, so as to obtain detection data of multiple groups of steel rail welding joint geometric shapes, calculation screening is performed on the detection data of the multiple groups of steel rail welding joint geometric shapes, actual measurement data are obtained, and waveforms reflecting the steel rail welding joint geometric shapes are drawn according to the actual measurement data, wherein the calculation screening process comprises the step of removing error data.

In the specific embodiment shown in fig. 1, the method for describing the rail welded joint further includes step S102, where the waveform is subjected to segmentation processing according to the waveform shape, so as to obtain a plurality of segments. The step lays a foundation for obtaining a more accurate mathematical model of the geometric shape of the steel rail welding joint.

In a specific embodiment of the present application, step S102 includes: the waveform is analyzed to obtain amplitude and wavelength reflecting the waveform shape, and the waveform is segmented according to the amplitude and wavelength to obtain a plurality of segments.

Specifically, as shown in fig. 2, according to wavelengths λ1 and λ2 corresponding to the convex-a waveform, the convex-B waveform and the concave waveform in fig. 2, and corresponding amplitudes a1 and a2, the convex-a waveform, the convex-B waveform and the concave waveform in fig. 2 are respectively subjected to segmentation processing to obtain a first segment, a second segment and a third segment, wherein the wavelengths λ1 corresponding to the first segment and the third segment are the wavelengths λ2 corresponding to the second segment. The waveform is segmented according to amplitude and wavelength to obtain three segments, and particularly, the segments are only exemplary, and the segmentation mode can be asymmetric in the practical application process.

In the specific embodiment shown in fig. 1, the method for describing the rail welded joint further includes step S103, where a parabolic fit or a cosine curve fit is performed on a plurality of segments, so as to obtain a corresponding parabolic function or cosine function.

In a specific embodiment of the present application, step S103 includes: according to the waveform shape, carrying out segmentation processing on the waveform to obtain a first segment and a third segment which are positioned at two ends of the waveform and a second segment which is positioned in the middle of the waveform; and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

In a specific embodiment of the present application, step S103 includes: and determining the parabolic function and the cosine function by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, wherein the product between the train running speed and the time is the wavelength corresponding to the segment.

Further, performing product operation with the time and the first preset multiple and the amplitudes corresponding to the first segment and the third segment respectively to obtain a first product and a second product; dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient; subtracting the ratio between the time and the first quotient or the second quotient by using a preset value to obtain a first difference value and a second difference value; and describing a first segment of the fitted waveform shape using a ratio between the first product and a product of the first quotient and the first difference, and describing a third segment of the fitted waveform shape using a ratio between the second product and a product of the second quotient and the second difference.

Specifically, as shown in fig. 2, the waveform in fig. 2 is subjected to segmentation processing according to the waveform shape to obtain a first segment, a second segment and a third segment, the first segment and the third segment are respectively fitted to obtain corresponding parabolic functions, and the second segment is fitted to obtain corresponding cosine functions, so that the obtained fitting result is that:

wherein, formula 5 is the fitting result to the male pattern-a in fig. 2, formula 6 is the fitting result to the male pattern-B in fig. 2, and formula 7 is the fitting result to the female pattern waveform in fig. 2. Z0 (t) in the above formula represents the vertical displacement caused by the welded joint of the steel rail; a1 and λ1 respectively represent the short wave amplitude and the short wave wavelength of the steel rail welding joint, and a2 and λ2 respectively represent the long wave amplitude and the long wave wavelength of the steel rail welding joint; v is the train running speed that needs to be changed at the time of simulation, t is the time the train is running to the area of influence of the rail weld joint, and the product of v and t is the wavelength.

In the specific embodiment shown in fig. 1, the method for describing the rail welded joint further includes step S104, obtaining a mathematical model describing the geometry of the rail welded joint according to a parabolic function and a cosine function.

Specifically, fig. 3 is a schematic diagram of a wheel rail impact load when the wheel passes through a rough rail, as shown in fig. 3, for a wheel rail impact force caused by a rail joint, a developer generally uses a low-order head rail dynamics analysis model, and thus defines two special types of acting forces objectively existing in the wheel rail impact vibration, namely a high-frequency impact load P1 and a low-frequency quasi-static load P2. The P1 force and the P2 force not only evaluate important indexes of the rolling stock on track damage, but also have important theoretical significance for analyzing the mechanism of track component failure and geometric state deterioration, and researching and developing high-speed and heavy-load track structures. As is well known, various pulse excitation sources exist in wheel-rail contact systems, for example, when a wheel impacts a rail, the rail is subjected to high-frequency impact load P1 and low-frequency quasi-static load P2, the frequency of the P1 force is very high, generally above 500Hz, the frequency of the P1 force is generally equal to the vibration frequency of the Hz contact between the unsprung mass of the vehicle and the mass of the rail, and the P1 force generally only occurs at the moment about 0.5ms after the wheel impacts the rail, and the P1 force decays very fast due to the inertia force of the rail, so that the force is not transmitted to the upper and lower sides of the vehicle, and the rail head cannot be directly damaged. While the P2 force acts on the entire rail system at a relatively low frequency, typically between 30 and 100Hz, the P2 force is sufficiently propagated to the rail substructure due to its long duration, and thus, while typically the magnitude of the load is somewhat smaller than P1, it is primarily responsible for the deformation of the rail and the destruction of the underlying structure.

In the prior art, when a cosine harmonic model is adopted to carry out wheel-rail coupling dynamics simulation analysis, the simulation analysis can accurately describe the P2 force under the action of the steel rail welding joint, but the description error of the P1 force is larger, and when a composite cosine harmonic model is adopted to carry out wheel-rail coupling dynamics simulation analysis, the simulation analysis can accurately describe the P1 force and the P2 force under the action of the steel rail welding joint, but the simulation result of irregularity of the steel rail welding joint of the convex-B in FIG. 2 is poorer. Therefore, in order to enable the modeled type to accurately describe the P1 and P2 forces from both the frequency domain and the time domain, the present application describes the waveform of the weld joint using a parabolic function and a cosine function according to the classification of the weld joint in the field.

Compared with the prior art, the mathematical model obtained by the method can better reflect the data characteristics in the aspects of describing the geometric shape of the steel rail welding joint, the wheel rail vertical force numerical simulation analysis under the time domain condition and the wheel rail vertical force numerical simulation analysis under the frequency domain condition. FIG. 4 is a schematic diagram of the geometric description of the three types of welding irregularities by various models of the present application in comparison with the results of the field test, as shown in FIG. 4, and the geometric description of the three types of welding irregularities by various models in comparison with the results of the field test, as shown in FIG. 2, for example, the geometric model employed in the present application can better describe the geometric shapes of the three types of welding joints as shown in FIG. 2, compared with the prior art. Fig. 5 is a schematic diagram of a simulation result of a wheel track vertical force time domain versus middle convex-a irregularity situation in the present application, fig. 6 is a schematic diagram of a simulation result of a wheel track vertical force time domain versus middle convex-B irregularity situation in the present application, fig. 7 is a schematic diagram of a simulation result of a wheel track vertical force time domain versus middle concave irregularity situation in the present application, and as shown in fig. 5 to fig. 7, wheel track vertical force responses under three types of welding irregularities are calculated by adopting a wheel track coupling dynamics model, and the comparison of the three irregularity model simulation results with a data simulation result of numerical simulation analysis of the irregularity situation shows that the present application can better reflect P1 force and P2 force under the time domain condition. Fig. 8 is an error analysis schematic diagram of simulation results and measured data of time domain comparison of wheel track vertical force in the application, as shown in fig. 8, description errors of three models on P2 force are all within 10%, cosine harmonic model errors are all greater than 10% for description of P1 force, when the composite cosine harmonic model describes male-B irregularity, error is greater than 10% when train speed is 300km/h and 350km/h, and mathematical models fitted in the application are all within 10% for P1 force and P2 force errors.

And, fourier transform is performed on the wheel-rail vertical force responses of the geometric shapes of the three types of welding joints to obtain responses in a frequency domain, and the comparison results of the simulation results corresponding to the geometric shapes of the three types of welding joints and the data simulation results of the numerical simulation analysis of the irregularity are shown in fig. 9 to 11 respectively, wherein fig. 9 is a schematic diagram of the wheel-rail vertical force frequency domain comparison of the wheel-rail vertical force frequency domain of the application and the simulation results of the bulge-a irregularity, fig. 10 is a schematic diagram of the wheel-rail vertical force frequency domain comparison of the bulge-B irregularity, and fig. 11 is a schematic diagram of the wheel-rail vertical force frequency domain comparison of the application and the simulation results of the bulge-a irregularity. As shown in fig. 9-11, the wheel-rail vertical force response in the frequency domain can be divided into two independent frequency bands, one of which is below 100Hz, approximately around 50Hz, which corresponds to the frequency of the P2 force, and both the mathematical model fitted by the present application and the prior art are consistent with the measured data. In a high-frequency region, it can be obviously seen that the cosine harmonic model can not simulate the high-frequency P1 force composite cosine harmonic model and can reflect high-frequency characteristics to a certain extent, but the high-frequency characteristics and the low-frequency characteristics can be reflected well by the fitted model in the application according to the simulation results of the high-frequency response and the test data.

In another embodiment of the present application, a method of testing a rail weld joint includes: carrying out wheel rail impact force numerical simulation analysis of the steel rail welding joint by utilizing a pre-obtained mathematical model; the obtaining process of the pre-obtained mathematical model comprises the following steps: obtaining measured data of the geometric shape of the steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the measured data; according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments; performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

In a specific embodiment of the present application, segmenting the waveform according to the shape of the waveform, to obtain a plurality of segments, includes: the waveform is analyzed to obtain amplitude and wavelength reflecting the waveform shape, and the waveform is segmented according to the amplitude and wavelength to obtain a plurality of segments.

In a specific embodiment of the present application, according to the waveform shape, the waveform is segmented to obtain a first segment and a third segment at two ends of the waveform, and a second segment at the middle of the waveform; and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

In a specific embodiment of the present application, the parabolic function and the cosine function are determined by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, where the product between the train running speed and the time is the wavelength corresponding to the segment.

In a specific embodiment of the present application, product operation is performed with the time and the first predetermined multiple, and the magnitudes corresponding to the first segment and the third segment respectively, so as to obtain a first product and a second product; dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient; subtracting the ratio between the time and the first quotient or the second quotient by using a preset value to obtain a first difference value and a second difference value; and describing a first segment of the fitted waveform shape using a ratio between the first product and a product of the first quotient and the first difference, and describing a third segment of the fitted waveform shape using a ratio between the second product and a product of the second quotient and the second difference.

The method for testing the steel rail welded joint can be used for executing the method for describing the steel rail welded joint described in any embodiment, and the implementation principle and the technical effect are similar and are not repeated here.

The foregoing description is only exemplary embodiments of the present application and is not intended to limit the scope of the present application, and all equivalent structural changes made by the present application and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present application.

Claims (10)

1. A method of describing a rail weld joint comprising:

obtaining measured data of the geometric shape of the steel rail welding joint, and obtaining a waveform reflecting the geometric shape of the steel rail welding joint according to the measured data;

according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments;

performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and

and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

2. A method of describing a rail welded joint according to claim 1, wherein the step of segmenting the waveform according to the waveform shape to obtain a plurality of segments comprises:

analyzing the waveform to obtain amplitude and wavelength reflecting the shape of the waveform;

and segmenting the waveform according to the amplitude and the wavelength to obtain a plurality of segments.

3. A method of describing a rail welded joint according to claim 1, wherein the step of segmenting the waveform according to the waveform shape to obtain a plurality of segments comprises:

according to the waveform shape, carrying out segmentation processing on the waveform to obtain a first segment and a third segment which are positioned at two ends of the waveform and a second segment which is positioned in the middle of the waveform;

and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

4. A method of describing a welded joint of rails according to claim 1, wherein said performing parabolic or cosine curve fitting on each of said segments to obtain a corresponding parabolic or cosine function comprises:

and determining the parabolic function and the cosine function by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, wherein the product between the train running speed and the time is the wavelength corresponding to the segment.

5. The method of claim 4, wherein performing parabolic fit or cosine curve fit on the segments to obtain corresponding parabolic functions or cosine functions, respectively, comprises:

performing product operation with the time and the first preset multiple and the amplitudes corresponding to the first segment and the third segment respectively to obtain a first product and a second product;

dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient;

subtracting the ratio between the time and the first quotient or the second quotient by a preset value to obtain a first difference value and a second difference value; the method comprises the steps of,

a first segment of the fitted waveform shape is described using a ratio between the first product and a product of the first quotient and the first difference, and a third segment of the fitted waveform shape is described using a ratio between the second product and a product of the second quotient and the second difference.

6. A method of testing a rail welded joint comprising:

carrying out wheel rail impact force numerical simulation analysis of the steel rail welding joint by utilizing a pre-obtained mathematical model;

the method comprises the steps of obtaining actual measurement data of the geometric shape of a steel rail welding joint, and obtaining waveforms reflecting the geometric shape of the steel rail welding joint according to the actual measurement data; according to the waveform shape, carrying out segmentation processing on the waveform to obtain a plurality of segments; performing parabolic fitting or cosine curve fitting on the segments respectively to obtain corresponding parabolic functions or cosine functions; and obtaining a mathematical model describing the geometric shape of the steel rail welding joint according to the parabolic function and the cosine function.

7. The method of testing a rail welded joint according to claim 6, wherein the step of segmenting the waveform according to the waveform shape to obtain a plurality of segments comprises:

analyzing the waveform to obtain amplitude and wavelength reflecting the shape of the waveform;

and segmenting the waveform according to the amplitude and the wavelength to obtain a plurality of segments.

8. The method of testing a rail welded joint according to claim 6, wherein the step of segmenting the waveform according to the waveform shape to obtain a plurality of segments comprises:

according to the waveform shape, carrying out segmentation processing on the waveform to obtain a first segment and a third segment which are positioned at two ends of the waveform and a second segment which is positioned in the middle of the waveform;

and performing parabolic fitting on the first segment and the third segment respectively to obtain corresponding parabolic functions, and performing cosine curve fitting on the second segment to obtain corresponding cosine functions.

9. The method of claim 6, wherein performing a parabolic fit or a cosine curve fit on the plurality of segments, respectively, to obtain a corresponding parabolic function or cosine function, comprises:

and determining the parabolic function and the cosine function by using the amplitude and the wavelength corresponding to the segment, the set train running speed and the time corresponding to the train running speed under the segment, wherein the product between the train running speed and the time is the wavelength corresponding to the segment.

10. The method of claim 9, wherein performing a parabolic fit or a cosine curve fit on the plurality of segments, respectively, to obtain a corresponding parabolic function or cosine function, comprises:

performing product operation with the time and the first preset multiple and the amplitudes corresponding to the first segment and the third segment respectively to obtain a first product and a second product;

dividing the wavelength corresponding to the first segment and the third segment with the train running speed to obtain a first quotient and a second quotient;

subtracting the ratio between the time and the first quotient or the second quotient by a preset value to obtain a first difference value and a second difference value; the method comprises the steps of,

a first segment of the fitted waveform shape is described using a ratio between the first product and a product of the first quotient and the first difference, and a third segment of the fitted waveform shape is described using a ratio between the second product and a product of the second quotient and the second difference.