Method for predicting steel rail light band

Abstract

To provide a method useful for maintenance of a steel rail, capable of evaluating a wheel-rail matching state on the basis of a predicted light band by predicting a state of the light band formed on the steel rail after a vehicle passes through the steel rail, in a technical field of track engineering data processing.SOLUTION: Determining a first material loss amount of the steel rail in a process from a state in which no light band occurs to a state in which a light band occurs on a surface of the steel rail, and determining a second material loss amount of each grid cell of a contact patch formed on the steel rail to be detected after the vehicle passes over the steel rail to be detected for a predetermined number of times; Further, a target area in which the second material loss amount is equal to or larger than the first material loss amount is determined as an area having a light band, and the position and width of the light band formed on the steel rail to be detected are predicted based on the information of the contact patch formed after the vehicle passes over the steel rail to be detected the predicted number of times.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the technical field of track engineering data processing, in particular to predicting steel rail light bands Regarding the method. [Background technology]

[0002] The steel rail light band is the contact area between the wheel and the steel rail after the vehicle has passed over the steel rail several times. The change in the light band reflects whether the wheel-rail relationship is normal. This is an important feature and can effectively prevent some problems caused by the change in the steel rail light band. It is possible. However, currently, there is a lack of technology to predict the light band of steel rails, and railway maintenance work is The work is incomplete. Summary of the Invention

[0003] The present application provides a method for predicting the steel rail light band, and after a vehicle passes through the steel rail, The state of the light band formed on the steel rail is predicted, and the wheel-rail contact is calculated based on the predicted light band. It is possible to evaluate the matching condition and is useful for the maintenance of steel rails. To achieve this, the present application adopts the following technical solutions: In a first aspect, the present application provides a method for predicting steel rail light bands, the method comprising: The process includes the steps of: The first material loss amount of the steel rail during the process is determined, and the vehicle is located on the steel rail to be detected. After a certain number of passes, the second grid cell of each contact patch formed on the steel rail to be detected The amount of material loss is predicted, and a target area where the second amount of material loss is equal to or greater than the first amount of material loss is detected by light. The area is determined to have a band, which is formed after the vehicle passes over the steel rail to be detected a predicted number of times. Based on the information of the contact patch, the position and Predict the width of the gap. In a possible implementation, each time a vehicle passes over a steel rail to be detected, Elliptical contact patches are formed on the steel rail, and the target area is the overlap of multiple elliptical contact patches. Based on this, the predicted number of times the vehicle passes over the steel rail to be detected is calculated. Based on the information of the contact patch formed after passing through the steel rail, The step of predicting the position and width of the light band includes: The information of the elliptical contact patch formed each time the object passes over the ball is acquired, and the elliptical contact patch The information includes the center point and semi-axis length of the elliptical contact patch, where the coordinates of the center point are the wheel center. The origin of the wheelset coordinate system is 0, and the origin of the wheelset coordinate system is the center of the wheelset. The X axis of the wheelset coordinate system is located on the center line and extends along the longitudinal direction of the steel rail. The Z axis of the wheelset coordinate system is vertically downward, and the Y axis of the wheelset coordinate system is the steel rail. The contact pad extends along the horizontal direction of the contact pad and forms a right-handed coordinate system with the X and Z axes. The major axis of the contact patch is along the X-axis direction, and the minor axis of the elliptical contact patch is along the Y-axis direction. Based on the center points and semi-axis lengths of the multiple elliptical contact patches that form the region, points within the target region are Determine the two intersections with the boundary of the target area along the Y axis of the wheelset coordinate system, where , the coordinate of the point in the target area on the X axis of the wheelset coordinate system, and The coordinates of the two intersections on the Y axis indicate the position of the light band formed on the steel rail to be detected. is used to indicate the distance between the coordinates of these two intersections on the Y axis of the wheelset coordinate system. The distance is used to indicate the width of the light band. In a possible implementation, the surface of the steel rail is changed from a state in which no light bands are generated to a state in which light bands are generated. The step of determining the first material loss amount of the steel rail in the process includes: , the first surface fractal dimension of the steel rail with the light band and the first surface fractal dimension of the steel rail without the light band The second surface fractal dimension is obtained, and the surface fractal dimension of the steel rail is The surface fractal dimension is used to indicate the roughness of the wheel specimen and the second surface fractal dimension. Wheel-rail friction tests were performed on the steel rail specimens with the same dimensions, and the steel rail specimens were of steel rail specimens when the surface fractal dimension of the specimen reaches the first surface fractal dimension The material loss amount is determined as a first material loss amount. In a possible implementation, the first surface fractal dimension is made of a steel rail with a light band. The maximum value of the surface fractal dimension of the multiple steel rail specimens was The surface fractogram of several steel rail specimens made of steel rails without a light band was calculated. is the average value of the dimension. In a possible implementation, the contacts formed each time the vehicle passes over the steel rail to be detected. When the contact patch is divided into a plurality of grid cells, the vehicle is positioned on a predetermined steel rail to be detected. After passing the number of times, the second material of each grid cell of the contact patch formed on the steel rail to be detected The step of predicting the amount of material loss includes: a vehicle passing over a steel rail to be detected; Each time, the amount of material loss in each grid cell of the contact patch formed on the steel rail to be detected is After the vehicle passes over the steel rail to be detected a predetermined number of times, The amount of material loss in each grid cell of the contact patch formed on the grid is accumulated to obtain the second material loss of each grid cell. The loss amount is obtained, and during the process of the vehicle passing over the steel rail to be detected a predetermined number of times, When the wheel passes through the steel rail, the contact point between the wheel and the steel rail to be detected is in one of the multiple grid cells. Located within the In a possible implementation, each time a vehicle passes over a steel rail to be detected, The steps for predicting the amount of material loss in each grid cell of the contact patch formed on the steel rail are as follows: Each time the vehicle passes over a steel rail to be detected, the wheel-rail contact point determine wheel-rail contact information corresponding to the grid cell in which the wheel-rail contact information is located, and the wheel-rail contact information is Wheel-rail contact stress in the grid cell where the wheel-rail contact point is located, and The wheel-rail contact information includes the relative sliding amount between the wheel and rail when rolling through the cell. Input the material loss amount of the grid cell into the wheel-rail wear model to obtain the wheel-rail wear amount. The model is designed to describe the relationship between wheel-rail contact information and steel rail material loss. Used. In a possible implementation, the wheel-rail contact points within the grid cell in which the wheel-rail contact points are located. stress JPEG2026015156000002.jpg79 is JPEG2026015156000003.jpg27119, where x is the coordinate of the wheel-rail contact point on the X axis of the wheelset coordinate system. where y is the coordinate of the wheel-rail contact point on the Y axis of the wheelset coordinate system, and a is the ellipse is the length of the major semi-axis of the elliptical contact patch, b is the length of the minor semi-axis of the elliptical contact patch, and N is the vehicle is the wheel-rail contact normal force when passing over the steel rail to be detected. In a possible implementation, the wheel-rail relative slip as the wheel rolls through the grid cells is calculated. running distance JPEG2026015156000004.jpg79 is JPEG2026015156000005.jpg2683, where JPEG2026015156000006.jpg77 is the lateral sliding velocity of the wheel within the grid cell, JPEG2026015156000007.jpg87 is the longitudinal sliding speed of the wheel within the grid cell, JPEG2026015156000008.jpg77 is the wheel rolling forward speed, JPEG2026015156000009.jpg710 is the length of the grid cell, Here, the lateral and longitudinal sliding velocities of the wheel within one grid cell are calculated based on the track rigidity. Based on the flexible coupling dynamic model and wheel-rail rolling contact model Required. In a possible implementation, the method for predicting steel rail light bands provided by the present application includes: The method further includes generating a plurality of sets of stochastic dynamics parameters, The dynamic parameters are used to simulate the movement of a vehicle passing through a steel rail. Each set of stochastic dynamic parameters is used, and the vehicle axle load, vehicle passing speed, wheel-rail Including coefficient of friction and steel rail irregularity. This application uses a test method to measure the time from when a steel rail does not produce light bands until the time when light bands appear. The first material loss amount in the process is determined, and the first material loss amount formed after the wheel-rail contact is determined after the wheel-rail contact is determined after the wheel-rail contact is determined. When the material loss of each grid cell of the contact patch reaches the first loss amount, a light band appears on the steel rail. The light band formed on the surface of the steel rail was determined based on the contact patch information. By predicting the position and width, the state of the light band formed on the steel rail can be predicted and the situation can be predicted. Based on the measured light band, the wheel-rail matching condition can be evaluated. This is useful for maintenance of the system. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 2 is a schematic diagram of a wheelset coordinate system provided by an embodiment of the present application. [Figure 2] 1 is a schematic diagram of a method for predicting steel rail light bands provided by an embodiment of the present application; [Figure 3] 2 is a schematic diagram of a method for predicting steel rail light bands provided by an embodiment of the present application. [Figure 4] FIG. 1 is a dimensional schematic diagram of a wheel specimen and a steel rail specimen provided by an example of the present application. [Figure 5] FIG. 1 is a schematic diagram illustrating the change in material loss of steel rail during wheel-rail friction process provided by an embodiment of the present application. [Figure 6] FIG. 1 is a schematic diagram illustrating the change in material loss rate of steel rail during wheel-rail friction process provided by an embodiment of the present application. [Figure 7] FIG. 1 is a schematic diagram illustrating the change of surface fractal dimension of steel rail during wheel-rail friction process provided by an embodiment of the present application; [Figure 8] 3 is a schematic diagram of a method for predicting steel rail light bands provided by an embodiment of the present application. [Figure 9] 4 is a schematic diagram of a method for predicting steel rail light bands provided by an embodiment of the present application. [Figure 10] 1 is a schematic diagram of a steel rail light band provided by an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0005] First, some technical terms related to the embodiments of this application will be explained. 1. Steel rail light band During repeated contact and friction between the steel rail surface and the wheels, an oxide layer forms on the steel rail surface. The bright marks formed by the wear are called photic bands. Observing and analyzing the light bands on steel rails provides important information such as steel rail wear and wheel wear. This information reflects the operational status of the railway and allows timely maintenance and repair measures to be taken as needed. Measures can be taken. The light band is formed by long-term wheel-rail interaction and the light band on the steel rail surface The formation process includes a material rapid wear stage, a light band formation stage and a light band stabilization stage. Here, the rapid material wear stage refers to the stage in which the steel rail loses material after wheel-rail friction begins. The amount of ions increases rapidly, but no obvious bright mark has yet formed on the steel rail surface. The light band formation stage refers to the stage where the wheel-rail continues to rub against each other, and the amount of material loss of the steel rail increases. The material loss rate slows and a visible bright mark gradually appears on the steel rail surface. The light band stabilization stage refers to the stage in which the material loss of the steel rail gradually increases and the material The material loss rate continues to decrease, and the light band traces in the wheel-rail contact area gradually become apparent. This refers to a stage where the new area is basically stable. 2. Surface fractal dimension Surface fractal dimension measures the roughness (i.e., the degree of irregularity and unevenness) of an object surface. It is a quantitative indicator that determines In the examples of this application, the surface roughness of a steel rail refers to the degree of unevenness of the surface of the steel rail. The unevenness of the steel rail surface is due to the manufacturing process of the steel rail or due to overuse. This is due to wear or corrosion during the process. The surface fractal dimension of the steel rail is determined by different methods, and in the examples of this application The box counting method was used to determine the surface fractal dimension of the steel rail. The estimating method mainly uses measuring instruments (such as microscopes) to observe the microscopic surface morphology of steel rails and measure the steel Count the number of boxes required to cover the rail surface and calculate the fractal dimension. Calculate the value of fractal dimension according to the formula. The formula for calculating fractal dimension is as follows: can be, JPEG2026015156000010.jpg2582In the above formula, Ds represents the surface fractal dimension of the steel rail, and i represents the surface fractal dimension of the steel rail during the measurement process. represents the smallest measurement scale continuously distributed on the surface of the lens (i.e., the positive The length of a side of a rectangular cell, a unit cube used to measure the third dimension in a three-dimensional rough surface field), and N(i) is the number of measurement scales, i.e., the number of squares packed into the rough surface. , i.e., the number of boxes required to cover the steel rail surface configuration. Details of determining the surface fractal dimension of steel rails using the box-counting method The details belong to the prior art, and further detailed description will be omitted in the examples of the present application. will be done. 3. Wheelset coordinate system The wheelset coordinate system is defined based on the running state of the vehicle on the steel rails. For example, as shown in FIG. 1, the origin 0 of the wheelset coordinate system is The X coordinate system of the wheelset is located on the center line of the vehicle (i.e., the center line of the left and right wheels of the vehicle). The axis extends along the longitudinal direction of the steel rail (i.e., the direction of vehicle travel or wheel rolling). , the Z axis of the wheelset coordinate system is vertically downward, and the Y axis of the wheelset coordinate system is steel It extends along the horizontal direction of the rail (i.e., the horizontal direction to the right in Figure 1) and is connected to the X-axis and Z-axis. Together they form a right-handed coordinate system. The wheelset coordinate system is used to calculate the position and orientation of the wheelset relative to the track, the wheel and the steel It serves as a reference standard used to describe contact relationships of steel rails, etc. When a vehicle passes over a steel rail, the contact point between the wheel and the steel rail (wheel-rail) The wheel-rail contact relationship is described by the Hertzian mechanics theory. Based on this relationship, after the vehicle passes over the steel rail, the wheel-rail contact point is placed on the steel rail. An elliptical contact patch is formed with its center point at the center of the wheel set. The major axis is along the X-axis of the wheelset coordinate system, and the minor axis is along the Y-axis of the wheelset coordinate system. In view of the current situation where there is no method for predicting the light band of a steel rail, the embodiment of the present application A method for predicting the light band of a steel rail after a vehicle has passed over the steel rail a predetermined number of times is provided. The condition of the light band formed on the surface is predicted in advance, the matching condition of the wheel and rail is evaluated, and the steel Useful for rail maintenance. The method provided by the embodiments of the present application is applicable to any scenario where wheel-rail friction exists. Steel rails in the light zone, steel rails in some turnout areas (areas where multiple tracks intersect) It is used to predict the rail light zone. In the following examples, it is mainly the turn-out zone. This paper takes the example of a steel rail light band prediction process in the turnout zone. As shown in FIG. 2, the method for predicting the steel rail light band provided by the embodiment of the present application is Includes S100 to S300. S100, the process from when no light bands appear on the surface of the steel rail to when light bands appear. Determine the first material loss of the steel rail. The first material loss is the light band that appears on the steel rail during the contact process between the wheel and the steel rail. The first material loss is the limit value. When the steel rail material loss reaches the first material loss amount, a clear light band will appear on the steel rail surface. is known to appear. Optionally, as shown in FIGS. 2 and 3, the above S100 may be specifically replaced with S101 to S102. This can be achieved by: S101, the first surface fractal dimension of steel rails with light bands and steel without light bands Obtain the second surface fractal dimension of the rail. The surface fractal dimension of the steel rail is used to indicate the roughness of the steel rail surface, The larger the value of the surface fractal dimension of the steel rail, the rougher the steel rail surface. do. Here, the steel rail having a light band is a steel rail in which a visible light band occurs on the surface of the steel rail. rails, for example, steel rails are selected as steel rails with light bands; Or other steel rails with light bands may be selected. Steel rails without light bands are also available. Steel rails without a light band on the surface of the iron rail. For example, steel rails without a light band are not used. Unused steel rails (steel rails shipped from the factory and not used) may also be used. stomach. In the examples of this application, for steel rails with and without light bands The fractal dimension was measured respectively to obtain the first surface fractal dimension and the second surface fractal dimension. Get the original. Selectable, the first surface fractal dimension is made of steel rails with light bands. is the maximum value of the surface fractal dimension of the multiple steel rail specimens, and the second surface fractal The dimension is the surface fractal of several steel rail specimens made of steel rails without light bands. is the average value of the dimension. In one implementation, the steel rail used is selected as a steel rail with a light band. The unused steel rails were selected as steel rails without light bands and counted by box count. The surface fractal dimensions of the steel rail with and without the light band were calculated using the The measurement process includes steps 1 to 3: Step 1: Using steel rails with and without light bands, Prepare a test piece. For example, the dimensions of the steel rail specimen are 2*2*1cm, and the number of steel rail specimens is The number is 50. Step 2, determine the surface fractal dimension of each steel rail specimen. The surface morphology of each steel rail test piece is observed using a laser microscope, etc., and the corresponding The number of boxes is counted and the surface fractal dimension is calculated by the above formula (1). Calculate the surface fractal dimension. All steel rails, selectable between steel rails without light strips and steel rails with light strips After obtaining the surface fractal dimension of the specimen, the Rajada rule (i.e., the 3σ rule) Steel rail test pieces of steel rails with a light band and steel rails of steel rails without a light band The surface fractal dimension of each test piece was subjected to outlier removal processing, and the surface fractal dimension was calculated. The processing principle of the 3σ standard is as follows: (μ-3σ, μ +3σ) and exclude surface fractal dimensions outside the range. , where μ is the average value of the surface fractal dimension, and σ is the standard deviation of the surface fractal dimension. be. Step 3: Surface fractal dimension of multiple steel rail specimens of steel rails with light bands The maximum value is taken as the first surface fractal dimension, and multiple steel rail samples of steel rails without light bands are used. The average value of the surface fractal dimensions of the test pieces is taken as the second surface fractal dimension. For example, a plurality of steel rails with a light band after being processed according to the Rajada criteria. The maximum value of the surface fractal dimension of the test piece was 2.09 (i.e., the first surface fractal (dimension), multiple steel rails of steel rails without light bands after processing by Rajada criteria The average value of the surface fractal dimension of the ball specimen is 2.24 (i.e., the second surface fractal dimension). In the examples of this application, the surface fractal dimension is used to calculate the surface fractal dimension of a steel rail. When determining whether there is a light band, 2.24 is used as the judgment standard for steel rails without a light band, and 2 .09 is selected as the standard for steel rails with light bands. S102, wheel test specimen and steel rail whose surface fractal dimension is the second surface fractal dimension Wheel-rail friction tests were performed on the steel rail specimens, and the surface fractographs of the steel rail specimens were The amount of material loss of the steel rail specimen when the surface fractal dimension reaches the first surface fractal dimension is calculated as the first Determined as the amount of material loss. In the examples of this application, wheel-rail friction tests were carried out on wheel specimens and steel rail specimens. A rubbing test was carried out to measure the change in the steel rail from the state where no light bands were generated to the state where light bands were generated. Calculate the amount of material loss of the steel rail (i.e., the first material loss amount). Specifically, During the friction process, material wear occurs on the steel rail surface, and the surface fractal dimension of the steel rail increases to When the surface fractal dimension reaches 1, it means that a light band appears on the steel rail, and this The material loss of the steel rail is the first material loss. The steel rail specimens used for wheel-rail friction tests have a surface fractal dimension of 2. The steel rail specimens are of the same structural dimension (i.e., steel rails without light bands) and have a surface flatness of 1000 mm. Steel rails whose fractal dimension is the second surface fractal dimension have been shipped and are not in use. After being shipped, the steel rails are subject to various factors and corrosion may occur. In actual sampling, the first steel rail specimens selected were shipped. The selected flat surface is likely to be relatively smooth because it is freshly cut and uncorroded. A smooth steel rail specimen was prepared so that its surface fractal dimension was the second surface fractal dimension. They may be subjected to a corrosion treatment before use in wheel-rail friction tests. In some examples, steel rail specimens were subjected to accelerated corrosion treatment using a neutral salt spray test. For example, a steel rail specimen may be prepared so that its surface fractal dimension is 2.24. After atomizing it at a concentration of 5%, it is placed in an environment of a sodium chloride neutral salt solution. In the wheel-rail friction test, the dimensions of the wheel test piece, the steel rail test piece and the vehicle axle load can be calculated according to the Hertz simulation rule (see the prior art for the specific calculation process) (This is not described in detail in this application.) By way of example, referring to FIG. The outer diameter of the piece is 59.4mm, the inner diameter is 29.7mm, and the wheel width is 10mm. There is a 5mm wide protrusion in the middle of the wheel, and the test specimen is fixed to the inner annular wall of the wheel test specimen. To accommodate this, there is a 6mm x 3.5mm slot. The outer diameter of the steel rail specimen is The inner diameter is 29.7 mm, and the width of the steel rail is 10 mm. The vehicle's axle load may be 17t (tons). Furthermore, the parameters of the wheel-rail friction test are load, wheel specimen rotation speed, steel rail The wheel test specimen rotation speed and rotation slip ratio are included. The rotation speed was 400 r / min, the steel rail specimen rotation speed was 398 r / min, and the rotating slide The test piece was rotated every 100 turns during the wheel-rail friction process. The surface condition of the steel rail was observed and the micromorphology of the surface of the steel rail was recorded until a contact light zone appeared. The surface roughness and diameter are measured. With the above settings, wheel-rail rolling contact fatigue is measured using a friction machine (e.g., a GPM rolling contact fatigue test machine). The process of forming the light band on the steel rail after the friction machine is The diameter change of the steel rail surface is measured using a micrometer, and the steel rail test piece is observed using a microscope. The surface morphology was observed, its surface fractal dimension was calculated, and the surface fractal dimension of the steel rail specimen was calculated. Obtain the amount of material loss of the steel rail specimen when the surface fractal dimension is equal to or greater than the first surface fractal dimension. do. In the examples of this application, the standard for measuring the amount of material loss of the steel rail is the wear of the steel rail. The wear depth is the change in the radius of the steel rail (i.e., the above It should be understood that the change in diameter is half of the change in diameter of the Based on the data recorded during the friction test, the change in the amount of material loss of the steel rail during the friction process was The change in the material loss rate of steel rails (shown in Figure 5) and the change in the material loss rate of steel rails (shown in Figure 6) The change in the surface fractal dimension of the ball (shown in Figure 7) can be analyzed. 5 to 7, the initial steel rail surface fractal dimension was 2.24. When rotating and rubbing at 100 to 500 turns, the amount of material loss increases rapidly, and the material loss rate The value of the specimen rapidly decreased, which was the stage of rapid wear of the material. As the specimen rotates and rubs, the amount of material loss continues to increase and the rate of material loss decreases. A visible light-bright mark gradually forms on the surface, and this stage belongs to the light band formation stage. The light band is considered to have formed when the specimen is rotated and rubbed at 1200 turns. When rotating and rubbing at 200 to 20,000 turns, the amount of material loss gradually increases, and the material loss rate The intensity continues to decrease, and the light band traces in the contact area gradually become apparent, and the bright areas are basically stable. If the surface fracturing of steel rails does not increase any more, this stage belongs to the photic zone stable stage. When the fractal dimension is 2.09 (first surface fractal dimension), the amount of material loss is 0.09 mm is. The above S100 and S200 allow a light band to appear on the steel rail surface from a state where there is no light band. During the process, the amount of material loss of the steel rail is obtained, and the amount of material loss is displayed as a light on the steel rail. It is used as a criterion for determining whether a band exists, and if so, predicts the position and width of the band. do. S200, after the vehicle passes over the steel rail to be detected a predetermined number of times, A second amount of material loss is predicted for each grid cell of the contact patch formed on the substrate. In addition, the light band of the steel rail to be detected (one steel rail) is predicted and the steel rail is detected. Each time a vehicle passes over the steel rail to be detected, An elliptical contact patch is formed on the steel rail to be detected. After passing over the rail several times, the steel rail to be detected comes into contact with the wheel repeatedly, resulting in multiple contact points. After the formed contact patches are overlapped to different degrees, the steel rail to be detected A final contact patch is formed on the surface of the (not necessarily a light zone). Each elliptical contact patch is divided into a number of grid cells, and the vehicle is positioned on the steel rail to be detected. The final contact patch formed after a number of passes contains a number of lattice cells, Material loss occurs in the surface area of ​​the steel rail corresponding to each grid cell. The following simulation method is used to simulate the vehicle passing through the steel rail in different postures. As shown in Figure 3 and Figure 8, the above S200 is specifically for predicting the amount of material loss of steel rails. This includes S201 to S202 described below. S201, every time the vehicle passes over the steel rail to be detected, The amount of material loss for each grid cell of the formed contact patch is predicted. When a vehicle passes over a steel rail, the wheels come into contact with the steel rail at a single point (i.e., the wheels (There is only one contact point between the rail and the steel rail), and each time the vehicle passes over the steel rail, the shape of the vehicle Since the force may be different, the contact point between the wheel and the steel rail (hereinafter referred to as the wheel-rail contact point) After the wheel comes into contact with the steel rail, friction occurs at the wheel-rail contact point. Wear occurs and bright contact patches form. In one embodiment, the above step S201 is realized by the following steps S2011 to S2012. This can be done. S2011, each time the vehicle passes through the steel rail to be detected, the wheel-rail contact point is located The wheel-rail contact information corresponding to the grid cells is determined. Here, the wheel-rail contact information is the wheel-rail contact point in the lattice cell where the wheel-rail contact point is located. Wheel contact stress and wheel-rail relative slippage when the wheel rolls through the grid cell Includes: Selectably, wheel-rail contact points and shapes are detected every time the vehicle passes a steel rail. Based on the shape parameters of the contact patch, the grid cell where the wheel-rail contact point is located is determined. The wheel-rail contact stresses in the rail can be calculated. In the actual analysis of wheel-rail contact mechanics, the geometry and contact of the wheel and steel rail are considered. Considering factors such as contact stress distribution, the elliptical model better represents the shape of the contact patch. Therefore, the shape of the contact patch is considered to be elliptical. Wheel-rail contact stress within the grid cell where the wheel-rail contact point is located JPEG2026015156000011.jpg79 satisfies equation (2): JPEG2026015156000012.jpg27119 formula (2) where x is the coordinate of the wheel-rail contact point on the X axis of the wheelset coordinate system, and y is is the coordinate of the wheel-rail contact point on the Y axis of the wheelset coordinate system. In equation (2), a and b are the shape parameters of the elliptical contact patch, and a is the represents the length of the major semi-axis of the patch (i.e., the longitudinal semi-axis length of the contact patch), and b represents the radius of the elliptical contact patch. represents the length of the minor semi-axis of the contact patch (lateral semi-axis length of the contact patch), and N is the wheel-rail contact normal force. Represents. In one implementation, the coordinates (x, y, z) of the wheel-rail contact point are calculated in the wheel-rail space It can be calculated according to the contact geometry (see prior art for details) For example, the coordinates of the wheel-rail contact point can be solved using the tracing method, specifically: As shown in equation (3): JPEG2026015156000013.jpg57129 formula (3) In the above equation, d w is the wheel tread contact angle, JPEG2026015156000014.jpg1590, l x , l y , l zare the direction cosines of the X, Y, and Z directions in the wheelset coordinate system, respectively. , JPEG2026015156000015.jpg861, JPEG2026015156000016.jpg955, JPEG2026015156000017.jpg834, f, y and y w are the side roll angle, swing head angle and lateral displacement of the wheel set, respectively. is the quantity, x o2 , y o2 , z o2 is the center of the wheel rolling circle in the wheelset coordinate system are the coordinates of JPEG2026015156000018.jpg950, JPEG2026015156000019.jpg951, JPEG2026015156000020.jpg949, R r is the radius of the wheel rolling circle, and d w is the wheel tread rolling circle in the wheelset coordinate system is the Y-axis coordinate. In one implementation, the longitudinal semi-axis length a and the lateral semi-axis length b of the elliptical contact patch are Hertzian contacts. It can be calculated according to the haptic mechanics assumption, specifically shown in the following equation (4): JPEG2026015156000021.jpg5379 formula (4) In the formula, N is the wheel-rail contact normal force, m and n are Hertz contact coefficients, A and B are the relative curvature constants, and k1 and k2 are constants related to the wheel-rail material. When the wheel-rail contact points of the steel rail are different, N, m, n, A and B are different. In some embodiments, the wheel rolling forward speed, the grid cell in which the wheel-rail contact point is located, The wheels are gridded based on the length of the grid cell, the lateral and longitudinal sliding speeds of the wheels within the grid cell. Calculate the relative wheel-rail slippage when rolling through a child cell. Specifically, the relative wheel-rail slippage when the wheel rolls through a grid cell JPEG2026015156000022.jpg79 is calculated using the following formula (5): JPEG2026015156000023.jpg2683 formula (5) In the above equation, JPEG2026015156000024.jpg77 is the lateral sliding velocity of the wheel within the grid cell, JPEG2026015156000025.jpg87 is the longitudinal sliding speed of the wheel within the grid cell, JPEG2026015156000026.jpg77 is the wheel rolling forward speed. In equation (5), the lateral sliding velocity of the wheel within the grid cell ( JPEG2026015156000027.jpg77) and longitudinal sliding velocity ( JPEG2026015156000028.jpg87) is a track rigid-flexible coupling dynamic model and wheel-rail rolling contact Specifically, first, the track rigid-flexible coupling dynamics Based on the dynamic model, the lateral displacement, swing head angle and side roll angle of the wheel set are calculated. Then, based on the lateral displacement of the wheelset, the swing head angle and the side roll angle, The coordinate system transformation matrix required for the wheel-rail rolling contact model is calculated using the The creep rate, rigid lateral creep rate and rigid rotational creep rate are obtained. Finally, Based on the rigid longitudinal creep rate, rigid transverse creep rate and rigid rotational creep rate. Based on this, the lateral sliding velocity of the wheel within the grid cell is JPEG2026015156000029.jpg77 and the longitudinal sliding velocity of the wheel within the grid cell Calculate JPEG2026015156000030.jpg87. In addition, since the vehicle's motion state may be different each time it passes over the steel rail, The wheel-rail contact points of the wheels and steel rails may be different, and the degree of wear of the steel rails may also be different. There is a possibility that it may differ. In an embodiment of the present application, a plurality of sets of stochastic dynamics parameters are used to estimate the speed at which a vehicle moves along a steel rail. The different motion states of the vehicle are simulated when passing through, and a set of stochastic dynamic parameters is Also called one stochastic dynamics sample, where each set of stochastic dynamics parameters is including vehicle axle load, vehicle passing speed, wheel-rail friction coefficient and steel rail irregularity, where: Vehicle axle load, vehicle passing speed and wheel-rail friction coefficient are important influencing factors of wheel wear. ,Steel rail irregularity (also called stochastic irregularity) is the geometrical change of the track in the turnout zone. It refers to the irregular situation where the geometric shape deviates from the ideal state in the spatial position. Different postures when passing through the gate (e.g. different entrance and turnout postures) The irregularities are horizontal irregularities, directional irregularities, height irregularities and gauge irregularities. Includes convex etc. The plurality of sets of stochastic dynamic parameters are generated stochastically and selectively sampled. 100 stochastic dynamics samples were collected using the Latin hypercube stochastic sampling method. The wavelength range of 100 stochastic irregularities is 1 to 100 m. do. Based on the description of stochastic dynamics parameters, specifically for the turnout zone, the trajectory The road rigid-flexible coupling dynamic model is given by the following equation (6): Using the out-orbit rigid-flexible coupling dynamics model: JPEG2026015156000031.jpg8147 formula (6) where G is the vehicle axle load, JPEG2026015156000032.jpg811 is the turnout total mass, JPEG2026015156000033.jpg85 is the vehicle turnout system acceleration, K is the total rigid matrix, JPEG2026015156000034.jpg106 C is the vehicle passing speed, JPEG2026015156000035.jpg86 is the wheel-rail friction coefficient, x, y, z are the coordinates of the wheel-rail contact point, {P} C teeth is the total weight matrix, JPEG2026015156000036.jpg843 is the steel rail unevenness. In Eq. (6), except for the stochastic dynamics parameters, the other parameters The meter is a constant. Note that m1 in equation (3) for calculating the wheel-rail contact point is calculated by {P} C in (3) and (6), the wheel-rail contact point and the lateral displacement of the wheelset The amount, swing head angle and side roll angle can be calculated, and further, in conjunction with Eq. (2), Wheel-rail contact stress You can get JPEG2026015156000037.jpg79. For the ith grid cell of the contact patch, its wheel-rail rolling contact model is given by the following equation (7 ) becomes: JPEG2026015156000038.jpg5741 formula (7) where: JPEG2026015156000039.jpg810 is the rigid longitudinal creep rate, JPEG2026015156000040.jpg910 is the rigid lateral creep rate, JPEG2026015156000041.jpg911 is the rigid rotation creep rate, JPEG2026015156000042.jpg915 is the vertical forward speed difference, JPEG2026015156000043.jpg1725 is the lateral forward velocity difference, JPEG2026015156000044.jpg1625 is the relative rotation speed difference, JPEG2026015156000045.jpg812 is the initial speed of the wheel rolling forward, JPEG2026015156000046.jpg1011 is the coordinate system transformation matrix ( JPEG2026015156000047.jpg1011 needs to be calculated). Coordinate system transformation matrix JPEG2026015156000048.jpg1011 JPEG2026015156000049.jpg1012 and Contains JPEG2026015156000050.jpg1011, and the calculation formula is as follows: In the JPEG2026015156000051.jpg46159 formula, JPEG2026015156000052.jpg88 is the left-hand transformation matrix, JPEG2026015156000053.jpg89 is the right-hand transformation matrix, JPEG2026015156000054.jpg88, JPEG2026015156000055.jpg89 is the wheel-rail contact angle on the left and right sides. The above vehicle-turnout track rigid-flexible coupling dynamic model is used to After calculating the lateral displacement of the rule set, the swing head angle, and the side roll angle, the coordinate system transformation Substitute into the column formula JPEG2026015156000056.jpg1011 is calculated, and then the coordinate system transformation matrix JPEG2026015156000057.jpg1011 is substituted into equation (7) to obtain the rigid longitudinal creep rate JPEG2026015156000058.jpg88, JPEG2026015156000059.jpg98, You can get JPEG2026015156000060.jpg99, JPEG2026015156000061.jpg88, JPEG2026015156000062.jpg98, JPEG2026015156000063.jpg99 is substituted into the equation below, and the lateral sliding velocity of the wheel within the grid cell is calculated. JPEG2026015156000064.jpg77 and the longitudinal sliding velocity of the wheel within the grid cell JPEG2026015156000065.jpg87 is obtained: JPEG2026015156000066.jpg23101x, y are the coordinates of the wheel-rail contact point, and y w is the lateral displacement of the wheelset. As mentioned above, JPEG2026015156000067.jpg77 and JPEG2026015156000068.jpg87 is substituted into equation (5) to obtain the wheel-rail relative slippage in the wheel-rail contact information. I get JPEG2026015156000069.jpg710. S2012, wheel-rail contact information is input into the wheel-rail wear model, and one lattice cell Obtain the amount of material loss in the loop. The above wheel-rail wear model is based on the change between wheel-rail contact information and steel rail material loss. Used to describe relationships. The wheel-rail wear model is shown in equation (8): JPEG2026015156000070.jpg2048 formula (8) In the above equation, JPEG2026015156000071.jpg611 is the amount of material loss in the grid cell, JPEG2026015156000072.jpg810 is the wear coefficient, JPEG2026015156000073.jpg68 is the wheel-rail contact stress within the grid cell, JPEG2026015156000074.jpg69 is the wheel-rail relative sliding distance when the wheel rolls through the cell, JPEG2026015156000075.jpg66 is the hardness of steel rails. In an embodiment of the present application, a vehicle is controlled by a plurality of sets of stochastic dynamics parameters to move along a steel rail. The different motion states of the vehicle are simulated as it passes through, and each set of stochastic dynamic parameters is Since the data corresponds to the wheel-rail contact point, S2011 to S2012 The grid cells in which each wheel-rail contact point is located during one pass of the steel rail in motion. Calculate the amount of material loss. S202, after the vehicle passes over the steel rail to be detected a predetermined number of times, The amount of material loss in each grid cell of the contact patch formed on the Get the loss amount. Here, during the process of the vehicle passing over the steel rail to be detected a predetermined number of times in different postures, When passing, the contact point between the wheel and the steel rail to be detected is one of the multiple grid cells. Located inside. In the embodiment of the present application, a vehicle passes over the steel rail to be detected a predetermined number of times in different postures. During the process, the number of times the wheel-rail contact point falls into each lattice cell is counted, and the material of the lattice cell is calculated. The loss amount is accumulated, and the material loss amount of the grid cell is calculated by dividing the loss amount by the amount of material loss that occurs each time the vehicle passes through the grid cell. It is the product of the amount of material lost and the number of times. S300, the target area where the second material loss amount is equal to or greater than the first material loss amount is defined as an area having a light band. and determining the contact patch formed after the vehicle passes over the steel rail to be detected a predicted number of times. Based on the information, the position and width of the light band formed on the steel rail to be detected is predicted. After the vehicle passes over the steel rail to be detected a predetermined number of times, the second material loss amount of a certain grid cell is Above the first material loss amount, a light band will appear in this area on the steel rail to be detected. The area consisting of the lattice cells in which the second material loss amount is equal to or greater than the first material loss amount is a light The area of ​​the band and further predict the position and width of the light band based on the contact patch information. If the second material loss amount of the grid cell is smaller than the first material loss amount, the steel rail to be detected is This indicates that there is no obvious light band in this area yet, and there is no need to predict the location and width of the light band. stomach. As can be seen from the above description of the embodiment, every time a vehicle passes over the steel rail to be detected, An elliptical contact patch is formed on the steel rail to be detected, and the target area with the light band is multi-layered. is the overlapping area of ​​the number of elliptical contact patches. As shown in FIGS. 8 and 9, the above step S300 can be selectively replaced by steps S301 and S302. This can be achieved. S301, an elliptical contact patch formed every time a vehicle passes over a steel rail to be detected The information of the elliptical contact patch includes the center point and semi-axis length of the elliptical contact patch. In addition, the function formula for the elliptical contact patch can be obtained from the center point and semi-axis length of the elliptical contact patch. It should be understood that the coordinates of the center point of the ellipse are based on the wheelset coordinate system. The wheelset coordinate system is shown in FIG. 1 and the wheelset coordinate system in the above embodiment. Please refer to the related description of the rulet coordinate system. When a vehicle passes over the steel rail to be detected M times (M is a predetermined number of times), the wheels and the steel There are M wheel-rail contact points between the rails, and each wheelset contact point is an elliptical contact pad. Corresponds to Chi. The center point of the elliptical contact patch is the wheel-rail contact point when the vehicle passes through the steel rail. The coordinates of the wheel-rail contact point and the semi-major axes (a and b) of the ellipse are calculated. See equations (3) and (4) for examples. S302, based on the center points and semi-axial lengths of the multiple elliptical contact patches forming the target area, A point in the target area has two intersections with the boundary of the target area along the Y axis of the wheelset coordinate system. and determining the coordinate of a point within the target area on the X-axis of the wheelset coordinate system, and The coordinates of the two intersections on the Y axis of the coordinate system are the coordinates of the light bands formed on the steel rail to be detected. Used to indicate the position, between the coordinates of two intersections on the Y axis of the wheelset coordinate system The distance is used to indicate the width of the light band. For example, referring to FIG. 10, the target area (light band) is the overlapping area of ​​contact patch 1 and contact patch 2. The boundary of the target area is assumed to be an elliptical contact area (i.e., the shaded area in the figure). The target area is composed of a part of the boundary of patch 1 and a part of the boundary of elliptical contact patch 2. For example, if we take an arbitrary point (say point C) in the wheelset coordinate system, the coordinates of point C on the X axis are Once given, point C is located at the intersection of two points with the boundary of the target area along the Y axis of the wheelset coordinate system. The method for determining the intersection points (points A and B in the figure) is as follows: The coordinates of point C on the X axis are The coordinate of point A on the Y axis can be calculated by substituting it into the function formula of patch 1, and the coordinate of point C on the X axis can be calculated by The coordinates of point B on the Y axis can be calculated by substituting the coordinates into the function formula for elliptical contact patch 2. , and calculate the distance between points A and B, which is the width of the light band at point C. By the above method, determining two corresponding intersection points of a plurality of points in the target area on the X axis; In this way, the situation of the entire light band can be known. For example, if we take one point C, Then, the coordinate of point C on the X axis is c1, the coordinate of point A on the Y axis is b1, and the coordinate of point B on the Y axis is If it is assumed that the distance between points A and B is b2 and d, the position of the light band is given by c1 and ( b1, b2), and the width range (b 1, b2), indicating the presence of a light band of width d. The coordinates representing the position and width of the light bands are in the wheelset coordinate system and can be selected. The position and width of the light strip may be expressed using a steel rail coordinate system. The coordinates of the set coordinate system can be converted to the steel rail coordinate system by coordinate transformation. The origin of the steel rail coordinate system is located on the center line of the steel rail, and the three axes are defined by the wheel set. This is the same as the definition of the three axes of the coordinate system. The above method allows the vehicle to pass over the steel rail a predetermined number of times, and then to measure the different cross sections of the steel rail. The width of the formed light band is predicted, and the wheel-rail matching status evaluation index is calculated to -The matching status of the rail can be evaluated, so that the steel rail can be maintained in a timely manner. For example, the evaluation index for the wheel-rail matching condition is The longitudinal rate of change in width (LRW) may be used, and the method for calculating the longitudinal rate of change in width of the light band is the same as that of the prior art. For details, please refer to the art and they will not be repeated in the examples of this application. Based on the above, the method for predicting the steel rail light band provided by the embodiment of the present application The method uses a test method to measure the progress of a steel rail from the state without a light band to the state where a light band appears. A first amount of material loss is determined for each grid cell of the contact patch after a predetermined number of wheel-rail contacts. When the amount of material loss reaches a first loss amount, it is determined that a light band has formed on the steel rail; Predicting the location and width of light bands formed on steel rail surfaces based on contact patch information This allows us to predict the state of the light band that will form on the steel rail, Based on the predicted light band, the wheel-rail matching condition can be evaluated, and the steel rail This is useful for maintaining the system. The above is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. However, all modifications and substitutions that can be easily thought of by a person skilled in the art within the technical scope of the present invention are included. Therefore, the scope of protection of the present invention is as defined in the claims. Subject to the scope.

Claims

1. The process from when no light bands appear on the surface of the steel rail to when light bands appear. determining a first amount of material loss of the roll; After the vehicle passes over the steel rail to be detected a predetermined number of times, a shape is formed on the steel rail to be detected. predicting a second amount of material loss for each grid cell of the contact patch; determining a target area in which the second amount of material loss is equal to or greater than the first amount of material loss as an area having a light band; , the contact patch formed after the vehicle has passed over the steel rail to be detected a predicted number of times. Based on the information, the position and width of the light band formed on the steel rail to be detected are predicted. and A method for predicting steel rail light bands, comprising:

2. Every time the vehicle passes over the steel rail to be detected, The target area is an overlapping area of ​​the elliptical contact patches. It is an area, The contact pattern formed after the vehicle passes over the steel rail to be detected a predicted number of times. Based on the information of the switch, the position and width of the light band formed on the steel rail to be detected are determined. The predicting step includes: An elliptical contact patch formed each time the vehicle passes over the steel rail to be detected The information of the elliptical contact patch includes the center point and semi-axis length of the elliptical contact patch. Including, The coordinates of the center point are expressed in coordinates based on the wheelset coordinate system, and the wheelset seat The origin 0 of the coordinate system is located on the center line of the wheel set, and the X axis of the wheel set coordinate system is The Z axis of the wheelset coordinate system extends along the longitudinal direction of the steel rail, and is directed vertically downward. The Y axis of the wheelset coordinate system extends along the lateral direction of the steel rail, and the X axis and Together with the Z axis, they form a right-handed coordinate system, with the long axis of the elliptical contact patch along the X axis, The minor axis of the elliptical contact patch is along the Y-axis direction, The target area is determined based on the center points and semi-axial lengths of the plurality of elliptical contact patches that form the target area. A point within the region is located at two intersections with the boundary of the target region along the Y axis of the wheelset coordinate system. Determine the difference score, where the coordinate of the point in the target area on the X axis of the wheelset coordinate system, and The coordinates of the two intersections on the Y axis of the railset coordinate system are is used to indicate the position of the light band formed on the Y axis of the wheelset coordinate system. the distance between the coordinates of the two intersections is used to indicate the width of the light band; The method of claim 1 ,

3. The steel rail surface is subjected to a process from when no light band is generated to when a light band is generated. The step of determining a first amount of material loss of the iron rail includes: The first surface fractal dimension of the steel rail with the light band and the second surface fractal dimension of the steel rail without the light band 2. The surface fractal dimension of the steel rail is obtained. The surface fractal dimension of the steel rail is the roughness of the steel rail surface. Used to indicate the size Wheel specimens and steel rail specimens whose surface fractal dimension is the second surface fractal dimension A wheel-rail friction test is performed on the specimen, and the surface fractograph of the steel rail specimen is the amount of material loss of the steel rail specimen when the surface fractal dimension reaches the first surface fractal dimension.

2. The method of claim 1, wherein the first amount of material loss is determined as:

4. The first surface fractal dimension is a surface fractal dimension of a plurality of steel rails made of the steel rails having the light bands. is the maximum value of the surface fractal dimension of the specimen, The second surface fractal dimension is a surface fractal dimension of a plurality of steel rails made of steel rails without the light band.

4. The method according to claim 3, wherein the surface fractal dimension is an average value of the surface fractal dimension of the test piece. Law.

5. The contact patch formed each time the vehicle passes over the steel rail to be detected is a plurality of divided into grid cells, After the vehicle passes over the steel rail to be detected a predetermined number of times, predicting the amount of second material loss for each grid cell of the contact patch formed on the Including, Every time a vehicle passes over the steel rail to be detected, a shape is formed on the steel rail to be detected. Predict the amount of material loss for each grid cell of the contact patch formed; After the vehicle passes over the steel rail to be detected a predetermined number of times, The amount of material loss in each grid cell of the contact patch formed on the A loss amount is obtained, and during the process of the vehicle passing over the steel rail to be detected a predetermined number of times, At each pass, the contact point between the wheel and the steel rail to be detected is located in one of the plurality of grid cells.

2. The method of claim 1, wherein the plurality of pixels are located within one grid cell.

6. Every time the vehicle passes over the steel rail to be detected, The step of predicting the amount of material loss for each grid cell of the contact patch formed on the surface includes: fruit, Each time the vehicle passes over the steel rail to be detected, the wheel-rail contact point is located. determining wheel-rail contact information corresponding to a grid cell, the wheel-rail contact information being Wheel-rail contact stress in the lattice cell where the wheel-rail contact point is located, and The wheel-rail relative sliding distance when rolling through a child cell is included. The wheel-rail contact information is input into a wheel-rail wear model, and the material loss of the grid cells is calculated. The wheel-rail wear model is based on wheel-rail contact information and steel rail material loss.

6. The method of claim 5, wherein the method is used to describe variation relationships between quantities.

7. Wheel-rail contact stress within the grid cell where the wheel-rail contact point is located teeth, where x is the coordinate of the wheel-rail contact point on the X axis of the wheelset coordinate system. y is the coordinate of the wheel-rail contact point on the Y axis of the wheelset coordinate system, and a is the is the length of the major semi-axis of the elliptical contact patch, and b is the length of the minor semi-axis of the elliptical contact patch. N is the wheel-rail contact normal force when the vehicle passes through the steel rail to be detected. and The relative wheel-rail slippage when the wheel rolls through the grid cell teeth, where is the lateral sliding velocity of the wheel within the grid cell, is the longitudinal sliding speed of the wheel within the grid cell, is the wheel rolling forward speed, is the length of the grid cell, The lateral and longitudinal sliding speeds of the wheels within the grid cells are calculated based on the track rigid-flexible It is calculated based on the bull coupling dynamic model and the wheel-rail rolling contact model.

7. The method of claim 6, wherein:

8. The method comprises: generating a plurality of sets of stochastic kinetic parameters; The plurality of sets of stochastic dynamics parameters are used to estimate the behavior of the vehicle as it passes through the steel rail. Each set of stochastic dynamic parameters is used to simulate the dynamic state of the vehicle. , including vehicle passing speed, wheel-rail friction coefficient and steel rail unevenness. The method of claim 1.

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