Railway fastener system rigidity optimization design method for reducing steel rail side abrasion

Abstract

The invention discloses a railway fastener system rigidity optimization design method for reducing steel rail side abrasion. The method comprises the steps that a vehicle-rail coupling dynamic model is established, analogue simulation is conducted, and a plurality of wheeltrack transverse force time travel curves and railhead transverse movement time travel curves when a train passes under the condition of different rigidities are obtained; establishing a relation curve of the wheel rail transverse force and the fastener vertical rigidity and a relation curve of the rail head transverse movement and the fastener vertical rigidity; obtaining a changing curve of the transverse force of the outer steel rail and the wheel rail along with the vertical rigidity of the fastener and a changing curve of the gauge enlargement along with the vertical rigidity of the fastener; and normalizing to the same coordinate system, and taking the fastener vertical rigidity corresponding to the intersection point of the two change curves as the optimized elastic backing plate rigidity. The method is used for solving the problem that in the prior art, the development speed of steel rail head side grinding is high, and consequently the maintenance and repair workload is large, and the purposes that the occurrence and development speed of steel rail side grinding is reduced by optimizing the rigidity of the fastener system, and the maintenance and repair workload is reduced are achieved.

Description

Technical Field

[0001] This invention relates to the field of railway fastening systems, and more specifically to a method for optimizing the stiffness of railway fastening systems to reduce rail side wear. Background Technology

[0002] Fasteners in rail structures play a crucial role in securing rails, maintaining rail gauge, providing track elasticity and longitudinal resistance, and adjusting rail height and lateral alignment. Taking the commonly used Type II elastic rail fastener in my country as an example, this type of fastener consists of an elastic rail clip, a rail under-rail elastic pad, a gauge baffle, a baffle seat, a spiral spike, a flat washer, and a nut. The rail under-rail elastic pad is the main component providing vertical and lateral stiffness to the fastener.

[0003] Rail head wear has a certain limit (generally 19mm according to relevant technical specifications). Once this limit is reached, the rail must be replaced promptly to avoid excessive gauge changes and safety risks such as derailment. Field statistics show that rail head wear develops extremely rapidly in some curved sections, reaching the replacement limit in approximately 1-2 years, resulting in a sharp increase in maintenance workload.

[0004] In existing technologies, the main measures to mitigate rail side wear on curved tracks are to increase the frequency of rail profile grinding and maintain the rail profile from significant changes due to rail head side wear, thereby ensuring stable contact between the wheel tread and the rail profile. However, while this existing technology can slow down the rate of rail side wear to some extent, rail grinding still requires a significant amount of additional manpower and resources, resulting in a substantial workload and high maintenance costs for track operators. Summary of the Invention

[0005] This invention provides a method for optimizing the stiffness of railway fastener systems to reduce rail side wear, thereby addressing the problem of rapid development of rail head side wear and resulting in a large workload for maintenance in existing technologies. The method aims to reduce the rate of occurrence and development of rail side wear and alleviate the workload of maintenance by optimizing the stiffness of the fastener system.

[0006] It is known that the stiffness of a fastening system consists of two parts: first, the vertical stiffness of the fastener, which is the vertical displacement of the rail when a unit load is applied vertically to the rail head; and second, the anti-overturning stiffness of the fastener, which is the lateral displacement of the rail head when a unit load is applied horizontally to the rail head. Therefore, the vertical stiffness and lateral anti-overturning stiffness of the fastener are strongly correlated. However, the inventors' team in this case found during their research that existing fastening system stiffness designs only consider vertical stiffness. Although the lateral anti-overturning capacity and gauge maintenance capacity of the fastener are core functions of the fastening system, they are not currently considered when designing the stiffness of the fastening system. At the same time, existing technologies lack research on the correlation between the lateral anti-overturning stiffness of the fastener and the side wear of curved rails, and have not combined the design of the vertical stiffness and lateral anti-overturning stiffness of the fastener. Furthermore, existing technologies only consider factors such as rail stress and sleeper support pressure when designing the vertical stiffness of fasteners. However, due to the safety margin in the track structure design, small variations in the vertical stiffness of fasteners will not cause the rail stress and sleeper support pressure to exceed the limits. Moreover, the rail stress and sleeper support pressure have not caused serious damage to track components in field use.

[0007] In summary, it is necessary to improve and optimize the existing fastener system stiffness design method from the perspective of reducing rail side wear. Therefore, this application is proposed. This application achieves this through the following technical solution:

[0008] A method for optimizing the stiffness of railway fastening systems to reduce rail side wear includes the following steps:

[0009] S1. Establish a vehicle-track coupled dynamics model, determine the stiffness range of the elastic pad, and determine the lateral stiffness of the fastener;

[0010] S2. Determine several different vertical stiffnesses of the fasteners based on the stiffness range of the elastic pad, and calculate the corresponding lateral anti-overturning stiffness of the fasteners respectively.

[0011] S3. Input the lateral stiffness of the fastener, several different vertical stiffnesses of the fastener and their corresponding lateral anti-overturning stiffness of the fastener into the vehicle-track coupled dynamics model, and simulate to obtain the time history curves of wheel-rail lateral force and rail head lateral displacement when the train passes under several different stiffness conditions.

[0012] S4. Based on the time history curves of the wheel-rail lateral force and the rail head lateral displacement, extract the maximum value of the wheel-rail lateral force and the maximum value of the rail head lateral displacement under different stiffness conditions.

[0013] S5. Based on the maximum value of wheel-rail lateral force under different stiffness conditions, establish the relationship curve between wheel-rail lateral force and fastener vertical stiffness; based on the maximum value of rail head lateral displacement under different stiffness conditions, establish the relationship curve between rail head lateral displacement and fastener vertical stiffness.

[0014] S6. Based on the relationship curve between the wheel-rail lateral force and the fastener vertical stiffness, obtain the curve showing the change of the outer rail wheel-rail lateral force with the fastener vertical stiffness; based on the relationship curve between the rail head lateral displacement and the fastener vertical stiffness, obtain the curve showing the change of the track gauge expansion with the fastener vertical stiffness.

[0015] S7. Normalize the curve of the lateral force of the outer rail wheel and rail as a function of the vertical stiffness of the fastener and the curve of the gauge expansion as a function of the vertical stiffness of the fastener to the same coordinate system, and take the vertical stiffness of the fastener corresponding to the intersection of the two curves as the optimized stiffness of the elastic pad.

[0016] To address the issues of rapid rail head wear and high maintenance workload in certain curved sections in existing technologies, this invention proposes a stiffness optimization design method for railway fastener systems to reduce rail head wear. This method first calculates several sets of different stiffness conditions as input to the simulation model, based on the existing structure of the fastener system and the assumption of uniform stiffness distribution of the rail pad. Each set of stiffness conditions includes: vertical fastener stiffness, lateral anti-overturning stiffness, and lateral fastener stiffness. The vertical fastener stiffness is set within the stiffness range of the elastic pad, the lateral anti-overturning stiffness is calculated based on the vertical fastener stiffness, and the lateral fastener stiffness can be adaptively set according to specific working conditions.

[0017] Subsequently, the time history curves of wheel-rail lateral force and rail head lateral displacement were obtained through simulation. Then, through relevant calculations, the curves of wheel-rail lateral force of the outer rail as a function of fastener vertical stiffness and the curves of gauge expansion as a function of fastener vertical stiffness were obtained. After normalizing these two curves, they were placed in the same figure, and their intersection point is the optimized elastic pad stiffness of this application.

[0018] This application creatively introduces the lateral anti-overturning stiffness of the fasteners to optimize the stiffness design of the fastener system. The principle is that when the bogie wheels pass through curved track sections, the lateral anti-overturning stiffness of the fasteners will affect the magnitude of the lateral displacement of the rail head. Appropriate lateral anti-overturning stiffness of the fasteners can reduce the impact between the wheel flange and the rail head, changing it from hard contact to soft contact, thereby reducing the lateral force between the wheel and the rail, and thus slowing down the occurrence and development rate of rail head side wear and reducing the workload of maintenance.

[0019] Furthermore, this application can ensure that the fasteners stably clamp the rails, preventing them from overturning excessively, and keeping the track gauge expansion within limits when the train passes, thus reducing the risk of train derailment. Therefore, this application achieves an optimized and coordinated design of the vertical stiffness and anti-overturning stiffness of the fastener system.

[0020] This application provides scientific and advanced guidance for the structural design and selection of fastener systems, and is particularly applicable to the technical requirements of low maintenance and high performance in small-radius curve sections.

[0021] Furthermore, in step S2, several point values ​​are selected at equal intervals within the stiffness range of the elastic pad as different vertical stiffnesses of the fastener.

[0022] This solution determines the corresponding range of elastic pad stiffness based on different line types and / or track structure types. Then, several points are selected at equal intervals within this range as point values ​​to represent different fastener vertical stiffnesses. This solution ignores the less influential spring clip clamping stiffness when determining the fastener vertical stiffness, which reduces computational load and improves optimization efficiency.

[0023] Furthermore, in step S2, the lateral anti-overturning stiffness of the fastener is calculated using the following formula:

[0024] ;

[0025] In the formula: k t For the lateral overturning stiffness of the fastener, k p For the vertical stiffness of the fastener, k c denoted as , b is the elastic clip clamping stiffness, d is the length of the elastic pad, and d is the spacing between clamping points.

[0026] Furthermore, the spring clip clamping stiffness k c Calculated using the following formula:

[0027] ;

[0028] In the formula: F c t represents the spring clip clamping pressure, and t represents the spring clip travel distance.

[0029] Furthermore, in step S3: the wheel-rail lateral force time history curve includes the outer rail lateral force time history curve and the inner rail lateral force time history curve, and the rail head lateral displacement time history curve includes the outer rail rail head lateral displacement time history curve and the inner rail rail head lateral displacement time history curve.

[0030] In this scheme, the time history curves of lateral force and rail head lateral displacement of the outer rail and inner rail are obtained through simulation, respectively, which provides sufficient support for subsequent calculations.

[0031] Furthermore, in step S4: the maximum value of the wheel-rail lateral force includes the maximum value of the outer rail lateral force and the maximum value of the inner rail lateral force under different stiffness conditions; the maximum value of the rail head lateral displacement includes the maximum value of the outer rail head lateral displacement and the maximum value of the inner rail head lateral displacement under different stiffness conditions.

[0032] In this scheme, the maximum value of the lateral force of the outer rail under different stiffness conditions is extracted from the time history curve of the lateral force of the outer rail; the maximum value of the lateral force of the inner rail under different stiffness conditions is extracted from the time history curve of the lateral force of the inner rail; the maximum value of the lateral displacement of the outer rail head under different stiffness conditions is extracted from the time history curve of the lateral displacement of the outer rail head; and the maximum value of the lateral displacement of the inner rail head under different stiffness conditions is extracted from the time history curve of the lateral displacement of the inner rail head.

[0033] Furthermore, in step S5:

[0034] The relationship curves between the wheel-rail lateral force and the fastener vertical stiffness include: the relationship curve between the maximum lateral force of the outer rail and the fastener vertical stiffness, and the relationship curve between the maximum lateral force of the inner rail and the fastener vertical stiffness.

[0035] The relationship curves between the rail head lateral displacement and the fastener vertical stiffness include: the relationship curve between the outer rail head lateral displacement and the fastener vertical stiffness, and the relationship curve between the inner rail head lateral displacement and the fastener vertical stiffness.

[0036] In this scheme, based on the maximum lateral force of the outer rail under several different stiffness conditions, several different fastener vertical stiffnesses and the corresponding maximum lateral force of the outer rail can be obtained, thus establishing the relationship curve between the maximum lateral force of the outer rail and the vertical stiffness of the fastener; the relationship curve between the maximum lateral force of the inner rail and the vertical stiffness of the fastener is similar.

[0037] Furthermore, based on the maximum lateral displacement of the outer rail head under several different stiffness conditions, several different fastener vertical stiffnesses and the corresponding maximum lateral displacement of the outer rail head can be obtained, thus establishing the relationship curve between the lateral displacement of the outer rail head and the vertical stiffness of the fastener; the relationship curve between the lateral displacement of the inner rail head and the vertical stiffness of the fastener is similar.

[0038] Furthermore, in step S6:

[0039] The curve showing the relationship between the maximum lateral force of the outer rail and the vertical stiffness of the fastener is used as the curve showing the variation of the wheel-rail lateral force of the outer rail with the vertical stiffness of the fastener.

[0040] By superimposing the lateral displacement of the outer rail head with the lateral displacement of the inner rail head, the curve of the gauge expansion as a function of the vertical stiffness of the fastener is obtained.

[0041] In this scheme, the lateral displacement of the outer rail head and the lateral displacement of the inner rail head under the same stiffness conditions (fastener vertical stiffness) are summed to obtain the gauge expansion. Then, the gauge expansion is matched with the corresponding stiffness conditions (fastener vertical stiffness) to obtain the curve of gauge expansion as a function of fastener vertical stiffness.

[0042] The optimized railway fastener system designed in this application has a stiffness sufficient for most railway lines. However, the inventors discovered during their research that for certain tracks with specific vibration reduction requirements (such as urban rail lines with high vibration reduction needs due to nearby residential areas or shopping malls) or those using ballastless track, it is necessary to use fastener elastic pads with lower vertical stiffness to ensure track elasticity. In these conditions requiring low vertical stiffness, directly reducing the vertical stiffness of the fasteners based on the optimized design in this application would lead to a simultaneous decrease in the lateral anti-overturning stiffness of the fasteners, thus hindering the suppression of rail side wear. To overcome this problem, this application also provides two technical means to maintain relatively stable lateral anti-overturning stiffness of the fasteners based on the optimized design in this application:

[0043] Technical means 1: After obtaining the optimized elastic pad stiffness in step S7, the actual elastic pad stiffness used is made smaller than the optimized elastic pad stiffness obtained in step S7, and also includes:

[0044] Grooves and / or holes are formed on the top and / or bottom surfaces of the elastic pad, and the density of the grooves and / or holes in the inner direction of the elastic pad is greater than the density in the outer direction of the elastic pad.

[0045] This solution involves reserving more grooves and / or holes on the inner side of the fastener pad, while using more flat plate structures on the outer side to provide rigidity. This results in uneven stiffness in the fastener pad, with the outer side having higher stiffness than the inner side. This approach can relatively increase the lateral overturning stiffness of the fastener. By setting the shape and / or number of grooves and / or holes according to specific working conditions, the lateral overturning stiffness of the fastener can remain relatively stable compared to the optimized elastic pad stiffness obtained in step S7, thereby overcoming the problem of simultaneous reduction in the lateral overturning stiffness of the fastener.

[0046] Those skilled in the art should understand that the inner side of the elastic pad in this solution refers to the side of the elastic pad closest to the center of the sleeper.

[0047] Technical means two: After obtaining the optimized elastic pad stiffness in step S7, the actual stiffness of the elastic pad used is made smaller than the optimized elastic pad stiffness obtained in step S7, and also includes:

[0048] The lateral overturning stiffness of the fastener corresponding to the optimized elastic pad stiffness is calculated and defined as the required lateral overturning stiffness k of the fastener. t1 ;

[0049] Keep k t1 Without changing the design stiffness of the elastic pad, the optimized length b1 of the elastic pad is calculated.

[0050] A metal pad of the same length b1 is added between the elastic pad of length b1 and the existing rail pad.

[0051] It should be noted that the design stiffness of the elastic pad in this scheme refers to the stiffness of the elastic pad required according to the design requirements when there are special vibration reduction needs (such as urban rail with high vibration reduction needs due to nearby residential areas or shopping malls) or when using track forms such as ballastless track.

[0052] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0053] 1. The present invention provides a method for optimizing the stiffness design of railway fastener systems to reduce rail side wear. By optimizing the stiffness design of the fastener system, the impact between the wheel flange and the rail head can be reduced, changing the contact from hard to soft, thereby reducing the lateral force between the wheel and rail, thus slowing down the rate of occurrence and development of rail head side wear and reducing the workload of maintenance.

[0054] 2. This invention provides a method for optimizing the stiffness of railway fastening systems to reduce rail side wear. This method ensures that the fasteners stably clamp the rails, preventing excessive overturning and keeping the track gauge expansion within limits when trains pass, thus reducing the risk of train derailment. Therefore, this application truly achieves optimized and coordinated design of the vertical stiffness and anti-overturning stiffness of the fastening system. It has scientific and advanced guiding significance for the structural design and selection of fastening systems, and is especially suitable for the technical requirements of low maintenance and high performance in small-radius curve sections.

[0055] 3. This invention provides a method for optimizing the stiffness of railway fastener systems to reduce rail side wear. It also proposes two technical means to maintain the relative stability of the lateral anti-overturning stiffness of the fasteners based on the optimized design. This overcomes the problem that when using fastener elastic pads with lower vertical stiffness to ensure the elasticity of the track for track types such as those with special vibration reduction requirements or ballastless track, the lateral anti-overturning stiffness of the fasteners is reduced simultaneously. Attached Figure Description

[0056] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0057] Figure 1 This is a flowchart illustrating a specific embodiment of the present invention;

[0058] Figure 2 This is the time history curve of the wheel-rail lateral force when a train passes through in a specific embodiment of the present invention;

[0059] Figure 3 This is a curve showing the relationship between the lateral force of the wheel and rail and the vertical stiffness of the fastener in a specific embodiment of the present invention.

[0060] Figure 4 This is a curve showing the relationship between the lateral displacement of the rail head and the vertical stiffness of the fastener in a specific embodiment of the present invention.

[0061] Figure 5 This is a schematic diagram illustrating the optimization of the vertical stiffness of the fastener in a specific embodiment of the present invention;

[0062] Figure 6 This is a cross-sectional view of the elastic pad in Embodiment 2 of the present invention;

[0063] Figure 7 This is a schematic diagram of the metal pad arrangement in Embodiment 3 of the present invention.

[0064] The attached diagram shows the markings and corresponding component names:

[0065] 1-Elastic pad, 2-Groove, 3-Rail pad, 4-Metal pad. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explaining the invention only and are not intended to limit the invention. In the description of this application, it should be understood that terms such as "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "high," "low," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application.

[0067] Example 1:

[0068] like Figure 1 The method for optimizing the stiffness of a railway fastening system to reduce rail side wear, as shown, includes the following steps:

[0069] Step S1: Establish a vehicle-track coupled dynamics model, determine the stiffness range of the elastic pad, and determine the lateral stiffness of the fastener.

[0070] In this embodiment, the method for establishing the vehicle-track coupled dynamics model includes:

[0071] Determine the track parameters of the fastener application curve, such as curve radius, curve superelevation, transition curve length, circular curve length, and track structure type, and establish a track model based on the above parameters.

[0072] Determine the train type, speed, axle load, wheelset distance, bogie center distance, and other vehicle information for the trains operating on the line where the fasteners are applied, and establish a vehicle model based on the above vehicle information;

[0073] Based on the track model and the vehicle model, a vehicle-track coupled dynamics model is established.

[0074] In this embodiment, the selectable range of elastic pad stiffness is set according to conditions such as line type and track structure type; for example, the selectable range is 10~100kN / mm for urban rail transit, 50~160kN / mm for conventional railways, and 70~200kN / mm for heavy-haul railways.

[0075] In this embodiment, the lateral stiffness of the fastener is set at 50 kN / mm.

[0076] Step S2: Select several points at equal intervals within the stiffness range of the elastic pad as different vertical stiffnesses of the fastener, and calculate the corresponding lateral anti-overturning stiffness k of the fastener for each. t :

[0077] (1)

[0078] (2)

[0079] In the formula: k t For the lateral overturning stiffness of the fastener, k p For the vertical stiffness of the fastener, k c Where is the spring clip clamping stiffness, b is the length of the elastic pad, d is the spacing between clamping points; F c t represents the spring clip clamping pressure, and t represents the spring clip travel distance.

[0080] Of course, in a more preferred embodiment, if the calculation cost is not considered, the vertical stiffness of the fastener in this embodiment can be the selected elastic pad stiffness plus the spring clip clamping stiffness.

[0081] Step S3: Input the lateral stiffness of the fastener, several different vertical stiffnesses of the fastener and their corresponding lateral anti-overturning stiffness into the vehicle-track coupled dynamics model, and perform simulation to obtain the time history curves of wheel-rail lateral force and rail head lateral displacement when the train passes under several different stiffness conditions.

[0082] The different stiffness conditions in this embodiment refer to different vertical stiffness of the fasteners and their corresponding lateral anti-overturning stiffness.

[0083] In this embodiment, the wheel-rail lateral force time history curve includes the outer rail lateral force time history curve and the inner rail lateral force time history curve, and the rail head lateral displacement time history curve includes the outer rail rail head lateral displacement time history curve and the inner rail rail head lateral displacement time history curve.

[0084] Taking a 23t axle load train passing through a 300m curve at a speed of 50km / h as an example, the time history curve of the wheel-rail lateral force during the train's passage is as follows: Figure 2 As shown.

[0085] Step S4: Based on the wheel-rail lateral force time history curve and the rail head lateral displacement time history curve, extract the maximum wheel-rail lateral force and the maximum rail head lateral displacement under different stiffness conditions;

[0086] In this embodiment, the maximum value of the wheel-rail lateral force includes the maximum value of the outer rail lateral force and the maximum value of the inner rail lateral force under different stiffness conditions; the maximum value of the rail head lateral displacement includes the maximum value of the outer rail head lateral displacement and the maximum value of the inner rail head lateral displacement under different stiffness conditions.

[0087] Step S5: Based on the maximum value of the wheel-rail lateral force under different stiffness conditions, establish the relationship curve between the wheel-rail lateral force and the vertical stiffness of the fastener; based on the maximum value of the rail head lateral displacement under different stiffness conditions, establish the relationship curve between the rail head lateral displacement and the vertical stiffness of the fastener.

[0088] In this embodiment, the relationship curve between the wheel-rail lateral force and the fastener vertical stiffness includes: the relationship curve between the maximum value of the outer rail lateral force and the fastener vertical stiffness, and the relationship curve between the maximum value of the inner rail lateral force and the fastener vertical stiffness.

[0089] The relationship curves between the rail head lateral displacement and the fastener vertical stiffness include: the relationship curve between the outer rail head lateral displacement and the fastener vertical stiffness, and the relationship curve between the inner rail head lateral displacement and the fastener vertical stiffness.

[0090] This embodiment is in Figure 2 Based on the time history curve of wheel-rail lateral force during train passage, the relationship curve between wheel-rail lateral force and fastener vertical stiffness is established as follows: Figure 3 As shown. Furthermore, the relationship curve between the rail head lateral displacement and the fastener vertical stiffness established in this embodiment is as follows: Figure 4 As shown.

[0091] Step S6: Based on the relationship curve between the wheel-rail lateral force and the fastener vertical stiffness, obtain the curve showing the change of the outer rail wheel-rail lateral force with the fastener vertical stiffness; based on the relationship curve between the rail head lateral displacement and the fastener vertical stiffness, obtain the curve showing the change of the track gauge expansion with the fastener vertical stiffness.

[0092] In this embodiment, the curve showing the relationship between the maximum lateral force of the outer rail and the vertical stiffness of the fastener is used as the curve showing the variation of the lateral force of the outer rail wheel and rail with the vertical stiffness of the fastener.

[0093] In this embodiment, the lateral displacement of the outer rail head is superimposed with the lateral displacement of the inner rail head to obtain the curve of the gauge expansion as a function of the vertical stiffness of the fastener.

[0094] Step S7: Normalize the curve of the lateral force of the outer rail wheel and rail as a function of the vertical stiffness of the fastener and the curve of the gauge expansion as a function of the vertical stiffness of the fastener to the same coordinate system, and take the vertical stiffness of the fastener corresponding to the intersection of the two curves as the optimized stiffness of the elastic pad.

[0095] In this embodiment, the normalization method is to treat the minimum value as 0 and the maximum value as 1 in the curves showing the variation of the lateral force of the outer rail wheel and rail with the vertical stiffness of the fastener and the variation of the gauge expansion with the vertical stiffness of the fastener, respectively.

[0096] In this embodiment, the two variation curves are normalized to the same coordinate system, as shown below. Figure 5 As shown; Figure 5 The black curve reflects the variation of the lateral force between the outer rail and the wheel with the vertical stiffness of the fastener, while the red curve reflects the variation of the gauge widening with the vertical stiffness of the fastener. The two curves... Figure 5 The vertical stiffness of the fastener corresponding to the intersection point is approximately 120 kN / mm. Therefore, the elastic pad stiffness of the fastener system optimized in this embodiment is 120 kN / mm. Substituting this back into formula (1), the corresponding lateral anti-overturning stiffness of the fastener can be obtained as 222010 N•m / rad.

[0097] The application effect of this embodiment is as follows:

[0098] On an actual R300 radius curve, field tests were conducted using elastic pads with different stiffnesses of 70kN / mm, 100kN / mm, 120kN / mm, 140kN / mm, and 200kN / mm to measure wheel-rail vertical and lateral forces, rail head lateral displacement, and other parameters. The test results are as follows:

[0099] When using an elastic pad with a stiffness of 70 kN / mm, the maximum lateral wheel-rail force is 23.9 kN, and the maximum gauge widening is 1.84 mm. When using an elastic pad with a stiffness of 200 kN / mm, the maximum lateral wheel-rail force is 37.1 kN, and the maximum gauge widening is 1.49 mm. However, when using the elastic pad with a stiffness of 120 kN / mm optimized by the method of this application, the maximum lateral wheel-rail force is 27.3 kN, which is 26.4% lower than that of the 200 kN / mm pad; the maximum gauge widening is 1.55 mm, which is 15.8% lower than that of the 70 kN / mm pad.

[0100] The above test results demonstrate that the elastic pad stiffness optimized by the method of this application can significantly optimize the wheel-rail lateral force and track gauge retention capability. Under the condition of ensuring that the fastener has excellent track gauge retention capability, it significantly reduces the wheel-rail lateral force and can delay the occurrence and development rate of rail side wear.

[0101] Example 2:

[0102] A method for optimizing the stiffness of railway fastener systems to reduce rail side wear is proposed. For certain conditions requiring lower vertical stiffness fastener elastic pads to ensure track elasticity, such as those with special vibration reduction needs (e.g., urban rail lines with high vibration reduction requirements due to nearby residential areas or shopping malls) or those using ballastless track, the vertical stiffness of the fasteners can be further reduced to meet the set requirements based on the optimized design in Example 1, and the following measures can be taken:

[0103] like Figure 6 As shown, grooves and / or holes are formed on the top and / or bottom surfaces of the elastic pad, and the density of the grooves and / or holes in the inner direction of the elastic pad is greater than the density in the outer direction of the elastic pad. Figure 6 The right side is the inside, and the left side is the outside.

[0104] This embodiment uses fasteners to assemble fatigue testing fixtures for elastic pads without grooves, and also uses... Figure 6 The lateral overturning stiffness of the rail was tested under two structures: one with a grooved elastic pad and the other with a grooved elastic pad. The vertical stiffness of the elastic pad in both structures was 100 kN / mm, and the total test load was 125 kN. The test results showed that with the elastic pad without grooves, the rail head lateral displacement was 1.36 mm, and the lateral overturning stiffness was 202197 N·m / rad; with the elastic pad with grooves, the rail head lateral displacement was 1.06 mm, and the lateral overturning stiffness was 280273 N·m / rad, an increase of approximately 38.6%. This demonstrates that the method of this embodiment can effectively improve the lateral overturning stiffness of the fastener while reducing its vertical stiffness, maintaining a side-wear resistance close to that under the optimized vertical stiffness conditions of the fastener in Example 1.

[0105] In a more preferred embodiment, the grooves and / or holes on the top and bottom surfaces of the elastic pad are distributed alternately.

[0106] Example 3:

[0107] A method for optimizing the stiffness of railway fastener systems to reduce rail side wear is proposed. For certain conditions requiring lower vertical stiffness fastener elastic pads to ensure track elasticity, such as those with special vibration reduction needs (e.g., urban rail lines with high vibration reduction requirements due to nearby residential areas or shopping malls) or those using ballastless track, the vertical stiffness of the fasteners can be further reduced to meet the set requirements based on the optimized design in Example 1, and the following measures can be taken:

[0108] The lateral overturning stiffness of the fastener corresponding to the optimized elastic pad stiffness is calculated and defined as the required lateral overturning stiffness k of the fastener. t1 In this embodiment, k t1 =222010 N•m / rad.

[0109] Keep k t1 Without changing the design stiffness of the elastic pad, the optimized length b1 of the elastic pad is calculated. In this embodiment, the design stiffness of the elastic pad is 60kN / mm. Substituting 60kN / mm into k in formula (1) p Substitute 222010 N•m / rad into k in formula (1) t The length of the elastic pad at this point is calculated to be b1 = 206 mm.

[0110] Therefore, this embodiment uses a 206mm long elastic pad, and sandwiches a 206mm long metal pad above the elastic pad and below the rail pad, such as... Figure 7 As shown.

[0111] This embodiment provides elasticity through an elastic pad under the metal pad. Traditional rail pads only serve as a buffer between the rail and the metal pad and do not provide elasticity.

[0112] Preferably, the metal pad is an iron pad.

[0113] Preferably, the thickness of the metal pad is greater than the thickness of the elastic pad.

[0114] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0115] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

Claims

1. A method for optimizing the stiffness design of a railway fastening system to reduce rail side wear, characterized in that, Includes the following steps: S1. Establish a vehicle-track coupled dynamics model, determine the stiffness range of the elastic pad, and determine the lateral stiffness of the fastener; S2. Determine several different vertical stiffnesses of the fasteners based on the stiffness range of the elastic pad, and calculate the corresponding lateral anti-overturning stiffness of the fasteners respectively. S3. Input the lateral stiffness of the fastener, several different vertical stiffnesses of the fastener and their corresponding lateral anti-overturning stiffness of the fastener into the vehicle-track coupled dynamics model, and simulate to obtain the time history curves of wheel-rail lateral force and rail head lateral displacement when the train passes under several different stiffness conditions. S4. Based on the time history curves of the wheel-rail lateral force and the rail head lateral displacement, extract the maximum value of the wheel-rail lateral force and the maximum value of the rail head lateral displacement under different stiffness conditions. S5. Based on the maximum value of wheel-rail lateral force under different stiffness conditions, establish the relationship curve between wheel-rail lateral force and fastener vertical stiffness; based on the maximum value of rail head lateral displacement under different stiffness conditions, establish the relationship curve between rail head lateral displacement and fastener vertical stiffness. S6. Based on the relationship curve between the wheel-rail lateral force and the fastener vertical stiffness, obtain the curve showing the change of the outer rail wheel-rail lateral force with the fastener vertical stiffness; based on the relationship curve between the rail head lateral displacement and the fastener vertical stiffness, obtain the curve showing the change of the track gauge expansion with the fastener vertical stiffness. S7. Normalize the curve of the lateral force of the outer rail wheel and rail as a function of the vertical stiffness of the fastener and the curve of the gauge expansion as a function of the vertical stiffness of the fastener to the same coordinate system, and take the vertical stiffness of the fastener corresponding to the intersection of the two curves as the optimized stiffness of the elastic pad.

2. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 1, characterized in that, In step S2, several point values ​​are selected at equal intervals within the stiffness range of the elastic pad to serve as different vertical stiffnesses of the fastener.

3. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 1, characterized in that, In step S2, the lateral anti-overturning stiffness of the fastener is calculated using the following formula: ； In the formula: k t For the lateral overturning stiffness of the fastener, k p For the vertical stiffness of the fastener, k c denoted as , b is the elastic clip clamping stiffness, d is the length of the elastic pad, and d is the spacing between clamping points.

4. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 3, characterized in that, The spring clip clamping stiffness k c Calculated using the following formula: ； In the formula: F c t represents the spring clip clamping pressure, and t represents the spring clip travel distance.

5. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 1, characterized in that, In step S3: the wheel-rail lateral force time history curve includes the outer rail lateral force time history curve and the inner rail lateral force time history curve; the rail head lateral displacement time history curve includes the outer rail rail head lateral displacement time history curve and the inner rail rail head lateral displacement time history curve.

6. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 5, characterized in that, In step S4: the maximum value of the wheel-rail lateral force includes the maximum value of the outer rail lateral force and the maximum value of the inner rail lateral force under different stiffness conditions; the maximum value of the rail head lateral displacement includes the maximum value of the outer rail head lateral displacement and the maximum value of the inner rail head lateral displacement under different stiffness conditions.

7. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 6, characterized in that, In step S5: The relationship curves between the wheel-rail lateral force and the fastener vertical stiffness include: the relationship curve between the maximum lateral force of the outer rail and the fastener vertical stiffness, and the relationship curve between the maximum lateral force of the inner rail and the fastener vertical stiffness. The relationship curves between the rail head lateral displacement and the fastener vertical stiffness include: the relationship curve between the outer rail head lateral displacement and the fastener vertical stiffness, and the relationship curve between the inner rail head lateral displacement and the fastener vertical stiffness.

8. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 7, characterized in that, In step S6: The curve showing the relationship between the maximum lateral force of the outer rail and the vertical stiffness of the fastener is used as the curve showing the variation of the wheel-rail lateral force of the outer rail with the vertical stiffness of the fastener. By superimposing the lateral displacement of the outer rail head with the lateral displacement of the inner rail head, the curve of the gauge expansion as a function of the vertical stiffness of the fastener is obtained.

9. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 1, characterized in that, After obtaining the optimized elastic pad stiffness in step S7, the following steps are also included: Grooves and / or holes are formed on the top and / or bottom surfaces of the elastic pad, and the density of the grooves and / or holes in the inner direction of the elastic pad is greater than the density in the outer direction of the elastic pad.

10. The method for optimizing the stiffness design of a railway fastener system to reduce rail side wear according to claim 1, characterized in that, After obtaining the optimized elastic pad stiffness in step S7, the following steps are also included: The lateral overturning stiffness of the fastener corresponding to the optimized elastic pad stiffness is calculated and defined as the required lateral overturning stiffness k of the fastener. t1 ; Keep k t1 Without changing the design stiffness of the elastic pad, the optimized length b1 of the elastic pad is calculated. A metal pad of the same length b1 is added between the elastic pad of length b1 and the existing rail pad.

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