A design method suitable for track stiffness distribution and homogenization in switch area

Abstract

The application discloses a design method suitable for track stiffness distribution and homogenization of a turnout area, which comprises the following steps: according to the uneven distribution characteristics and structural features of the overall stiffness of the turnout, the turnout is divided into six substructures; considering that the sensitivity of the wheel-rail dynamic response parameters to the stiffness of the track under the pad and the stiffness of the pad under the plate is different, a function is constructed with the minimum comprehensive dynamic response of the track as the target, and the optimal value of the overall stiffness of the turnout area is obtained; under the condition of the optimal value, the train has the lowest response peak value when passing through the turnout at high speed, and the smoothness is good when passing through the turnout area; the distribution rule of the pad under the plate in different track sections is obtained reversely through the optimal overall stiffness value to ensure the overall stiffness to be stable; the application takes the matching of the dynamic response of the turnout area and the track stiffness and the uniformity of the stiffness distribution as the target, comprehensively considers the interaction mechanism of multiple components such as the interval iron and the shared long pad in the turnout and the super-elastic material performance of the pad under the plate, and realizes the homogenization design of the overall stiffness of the high-speed turnout.

Description

Technical Field

[0001] This invention belongs to the field of track uniformity design technology, specifically relating to a design method for track stiffness distribution and uniformity in turnout areas. Background Technology

[0002] Turnouts are essential basic equipment for enabling train switching or cross-track operation. The stiffness of a turnout track mainly consists of the bending stiffness of the rails, the stiffness of the fastening system, and the stiffness of the ballast and subgrade. Given a fixed ballast and subgrade stiffness, the stiffness of the turnout track requires careful consideration of the proper matching of the under-rail pads and under-slab pads due to the influence of special structures such as the turnout slide plate. Furthermore, turnouts connect multiple rails by sharing long pads and spacers. Combined with the variable cross-section rail profile of turnouts, the overall track stiffness is unevenly distributed longitudinally along the track due to the influence of multiple coupling factors, including rail cross-section, pad length, sleeper length, and spacers. Therefore, turnout track stiffness becomes a crucial factor affecting wheel-rail dynamics and ride comfort. With the further increase in railway operating speed and the lightweight improvement of CR450 trains, the track vibration and stiffness irregularity caused by unreasonable track stiffness design will be further amplified, which will affect the service life of turnout rails and significantly increase the cost of railway operation and maintenance. Therefore, it is necessary to adjust the track stiffness to adapt to the lightweight modification of 400 km / h high-speed trains.

[0003] Regarding the design method for uniform stiffness of turnouts, in foreign countries, the uniform stiffness of turnouts in French high-speed railways is controlled by the dynamic load change rate and the maximum vertical displacement of the wheel. By ensuring that the overall dynamic stiffness of the nodes in the ballastless / slabless turnout area is consistent with that of the section, the dynamic load change rate and the vertical displacement of the wheel do not exceed 1.3 and 0.2 mm / m, respectively. The uniform stiffness of turnouts in German high-speed railways is controlled by the stress at the bottom of the rail. The vertical nodes of the turnout and the section fastener are set at 17.5 kN / mm and 22.5 kN / mm, respectively. The uniform stiffness is achieved by designing the static stiffness of the elastic pads in different parts of the turnout. Foreign countries mainly achieve uniform stiffness by ensuring that the stiffness of the section and the turnout is consistent, ignoring the uniform stiffness of the track stiffness inside the turnout [1].

[0004] Domestically, Wang Ping, Sun Jialin, Qian Kun, and others have used the finite element method to design a uniform stiffness for turnout tracks. They analyzed the influence of spacers, slides, and the support layer under the point / core rail slab on turnout stiffness and proposed a uniform stiffness design scheme for ballastless turnouts. They mainly designed the turnout rail stiffness by setting elastic pads in stages, aiming at the overall stiffness of each turnout sleeper, and adjusting the rubber pads under the slab to achieve uniform turnout track stiffness. However, this method only optimizes the turnout stiffness distribution, neglecting the wheel-rail dynamic response and stiffness matching.

[0005] Therefore, how to provide a design method suitable for track stiffness distribution and homogenization in turnout areas is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a design method for track stiffness distribution and homogenization in turnout areas. With the goal of matching and homogenizing the dynamic response and track stiffness distribution in turnout areas, it realizes the homogenization design of track stiffness in high-speed turnouts, providing basic support and theoretical basis for the research and development of high-speed turnouts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a design method suitable for track stiffness distribution and homogenization in turnout areas, comprising the following steps:

[0008] Step 1: Divide the turnout track section. Based on the uneven distribution of the overall stiffness of the turnout and its structural characteristics, the turnout is divided into six substructures from one end to the other. The area between adjacent substructures is the turnout track section. The track components in different turnout track sections have different stiffness variation ranges.

[0009] Step Two: Both the rail pad and the slab pad are elastic components, directly affecting the stiffness variation of the turnout track. When designing for uniform turnout track stiffness, the matching of turnout track stiffness and dynamic response is the research objective. The matching of dynamic response is affected by the sensitivity of dynamic parameters, which include five parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration. The ratio of the rate of change of a dynamic parameter to the rate of change of the corresponding overall track stiffness is defined as the sensitivity coefficient of that dynamic parameter.

[0010]

[0011] In Equation 1, K1 is the overall track stiffness before optimization, K2 is the overall track stiffness after optimization, D1 is the selected dynamic parameters before optimization, and D2 is the selected dynamic parameters after optimization. All five dynamic parameters are processed according to Equation 1.

[0012] Step 3: Calculate the sensitivity coefficients of the changes in the stiffness of the rail pad and the changes in the stiffness of the slab pad to the dynamic parameters according to Formula 1. Obtain the average sensitivity coefficient of each dynamic parameter in the corresponding track section based on the aforementioned sensitivity coefficients. Since the calculated wheel-rail dynamic effect is a time history curve, a sensitivity coefficient can be calculated at each moment. Therefore, the average value of the corresponding track section is used as the subsequent evaluation index. Considering that the sensitivity of each dynamic parameter to the stiffness of the rail pad and the slab pad is different, a function is constructed with the goal of minimizing the overall dynamic response of the track. An evaluation formula f for the optimal overall track stiffness is proposed. This formula includes all track sections divided in the turnout area to obtain the overall stiffness of the track in the turnout area. Under the condition of optimal overall track stiffness, the peak value of the dynamic response of the train passing through the turnout is minimized.

[0013]

[0014] In Equation 2 and These are the sensitivity coefficients of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration to changes in track component stiffness, respectively. i=1 represents the stiffness of the under-rail rubber pad; i=2 represents the stiffness of the under-slab rubber pad, N. r U r U g A r A g These are the standard values ​​of five dynamic parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration; β knr β kur β kug β kar and β kag These represent the weighting coefficients for wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively; N br U br U bg A br and A bg These represent the calculated dynamic response values ​​of the corresponding parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively.

[0015] Step 4: After calculating the optimal value of the overall stiffness of the turnout track according to Formula 2, calculate the stiffness distribution law of the rail pad and the plate pad under different turnout track sections based on this value.

[0016] The beneficial effects of this invention are as follows: This invention divides the turnout into sections and then performs uniform design. With the track stiffness variation and wheel-rail dynamic response matching corresponding to different sections as the goal, the optimal value of the overall stiffness of the turnout track is obtained. Under this condition, the peak value of the dynamic response of the train passing through the turnout is the smallest, which is the most stable. Relying on the overall optimal stiffness of the turnout track, the under-rail rubber pad stiffness and under-slab rubber pad stiffness of each track section structure matching are calculated in reverse, thereby achieving the purpose of track stiffness distribution and uniformity in the turnout area.

[0017] Preferably, in step one, the six substructures include a first substructure, a second substructure, a third substructure, a fourth substructure, a fifth substructure, and a sixth substructure. The first substructure corresponds to the part in front of the tip of the switch rail, the second substructure corresponds to the switch part, the third substructure corresponds to the turnout track guide curve part, the fourth substructure corresponds to the part of the guide curve near the end of the frog where the two guide rails share a pad, the fifth substructure corresponds to the part of the frog where the two wing rails and the two frog rails share a pad, and the sixth substructure corresponds to the part of the turnout transition after the turnout, where the center rail and the wing rails share a pad.

[0018] The resulting technical effect is as follows: Due to the complex structure of the turnout area, the track structure in the turnout area is much more complex than that of the track in the section. Within the turnout area, there are various types of rail components, the length of sleepers and pads varies, and the stiffness of the pads under the pads also varies. In addition, there are track components that are not present in the section, such as spacers, guard rails, and slides. Because these components are unevenly distributed within the turnout area, the track stiffness in the turnout area is unevenly distributed along the longitudinal direction of the track. Therefore, the turnout area is divided into six substructures, and the overall stiffness of the turnout area is optimized based on the six substructures to solve for the optimal value.

[0019] Preferably, the first substructure consists of a main rail, a rail pad, fasteners, a steel pad, a plate pad, and sleepers; the second substructure consists of a switch rail, a main rail, and a shared steel pad. When wheel load is applied to the switch rail, it can be transferred to the main rail of the other track through the shared steel pad, and the main rail provides support; the third substructure mainly includes four rails: a straight main rail, a curved main rail, a straight guide rail, and a curved guide rail. Each rail is supported by a steel pad, and the wheel load is transferred through the sleepers, with all four rails providing support simultaneously; in the fourth substructure, the straight guide rail and the curved guide rail share a single steel pad, and the wheel load applied to the straight or curved guide rail is transferred to the other guide rail through the shared steel pad, providing support; in the fifth substructure, the wheel load is applied to the center rail and transferred through the steel pad, with the other center rail and the two wing rails providing support simultaneously; in the sixth substructure, the wheel load is applied to the center rail and transferred through the steel pad, with the wing rails providing support.

[0020] The resulting technical effect is that the force principle of different track sections under wheel load is different. There may be one or more rails bearing the load. Therefore, the stiffness of different substructures is different. So it is necessary to propose an optimal stiffness distribution law of the under-plate rubber pad based on dynamics to ensure the overall stiffness is stable.

[0021] Preferably, in step two, the rail pad is a rail rubber pad laid under the rail, and there is an iron pad under the rail rubber pad. The plate pad is a plate rubber pad under the iron pad.

[0022] The resulting technical effect is that many factors affect the change in track stiffness in the turnout area, but the two elastic components, the rail pad and the plate pad, have a greater impact on the change in track stiffness in the turnout area.

[0023] Preferably, in step three, the dynamic response calculation values ​​of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are obtained based on the vehicle-turnout coupled dynamics model.

[0024] Preferably, in step three, the weighting coefficients for the wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are 0.7, 0.4, 0.4, 0.6, and 0.6, respectively. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the six substructures of a design method for track stiffness distribution and homogenization in turnout areas according to the present invention.

[0026] Figure 2 This is a schematic diagram of the first substructure defined in this invention;

[0027] Figure 3 This is a schematic diagram of the second substructure defined in this invention;

[0028] Figure 4 This is a schematic diagram of the third substructure defined in this invention;

[0029] Figure 5 This is a schematic diagram of the fourth substructure defined in this invention;

[0030] Figure 6 This is a schematic diagram of the fifth substructure defined in this invention;

[0031] Figure 7 This is a schematic diagram of the sixth substructure defined in this invention;

[0032] Figure 8 This is a diagram showing the optimized stiffness distribution of high-speed turnouts according to the present invention.

[0033] 1. Basic rail, 2. Point rail, 3. Straight basic rail, 4. Curved basic rail, 5. Straight guide rail, 6. Curved guide rail, 7. Wing rail, 8. Long center rail, 9. Short center rail. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] See the appendix of this invention. Figures 1 to 8 According to an embodiment of the present invention, a design method for track stiffness distribution and homogenization in turnout areas includes the following steps:

[0036] Step 1: Divide the turnout track section. Based on the uneven distribution of the overall stiffness of the turnout and its structural characteristics, the turnout is divided into six substructures from one end to the other. The area between adjacent substructures is the turnout track section. The track components in different turnout track sections have different stiffness variation ranges.

[0037] Step Two: Both the rail pad and the slab pad are elastic components. The rail pad is the rubber pad under the rail, and the slab pad is the rubber pad under the iron pad. The rail pad and the slab pad directly affect the stiffness variation of the turnout track. When designing the turnout track stiffness uniformly, the matching of turnout track stiffness and dynamic response is taken as the research objective. The matching of dynamic response is affected by the sensitivity of dynamic parameters. The dynamic parameters include five dynamic parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration. The ratio of the rate of change of a dynamic parameter to the rate of change of the corresponding overall track stiffness is defined as the sensitivity coefficient of that dynamic parameter.

[0038]

[0039] In Equation 1, K1 is the overall track stiffness before optimization, K2 is the overall track stiffness after optimization, D1 is the selected dynamic parameters before optimization, and D2 is the selected dynamic parameters after optimization. All five dynamic parameters are processed according to Equation 1. This sensitive parameter is used to represent the degree of influence between the rate of change of dynamic parameters and the rate of change of stiffness.

[0040] Step 3: Calculate the sensitivity coefficients of the changes in the stiffness of the rail pad and the changes in the stiffness of the under-slab pad to the dynamic parameters according to Formula 1. Obtain the average sensitivity coefficient of each dynamic parameter in the corresponding track interval based on the aforementioned sensitivity coefficients. Since the calculated wheel-rail dynamic effect is a time history curve, a sensitivity coefficient can be calculated at each moment. Therefore, the average value of the corresponding track interval is used as the subsequent evaluation index. Considering that the sensitivity of each dynamic parameter to the stiffness of the rail pad and the under-slab pad is different, a function is constructed with the goal of minimizing the overall dynamic response of the track. An evaluation formula f for the optimal overall track stiffness is proposed. Under the condition of optimal overall track stiffness, the peak value of the dynamic response of the train passing through the turnout is minimized.

[0041]

[0042] In Equation 2 and These are the sensitivity coefficients of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration to changes in track component stiffness, respectively. i=1 represents the stiffness of the under-rail rubber pad; i=2 represents the stiffness of the under-slab rubber pad, N. r U r U g A r A g These are the standard values ​​of five dynamic parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration; β knr β kur β kug β kar and β kag These represent the weighting coefficients for wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively; N br U br U bg A br and A bg These represent the calculated dynamic response values ​​of the corresponding parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively.

[0043] Step 4: After calculating the optimal value of the overall stiffness of the turnout track according to Formula 2, calculate the stiffness distribution law of the rail pad and the plate pad under different turnout track sections based on this value.

[0044] In step one, the six substructures include the first substructure, the second substructure, the third substructure, the fourth substructure, the fifth substructure, and the sixth substructure. The first substructure corresponds to the front part of the tip of the switch rail. The first substructure is illustrated by section AA. (See attached diagram.) Figure 2The second substructure corresponds to the switch section. The second substructure is illustrated by the BB section. (See attached diagram.) Figure 3 The third substructure corresponds to the turnout track guide curve section, illustrated by the CC section. (See attached diagram.) Figure 4 The fourth substructure corresponds to the section of the guide curve near the end of the guide rail where the two guide rails share a common pad, as shown in the DD section diagram. (See attached diagram.) Figure 5 The fifth substructure corresponds to the portion of the feeder where the two wing rails and two center rails share the same pad, illustrated by the EE section diagram. (See attached diagram.) Figure 6 The sixth substructure corresponds to the section after the turnout transition. Its center rail and wing rail share a common pad, as shown in the FF section diagram. See attached diagram. Figure 7 .

[0045] The first substructure consists of the main rail 1, rail pads, fasteners, iron pads, under-slab pads, and sleepers. The second substructure consists of the switch rail 2, the main rail 1, and their shared iron pads. When wheel loads are applied to the switch rail, they can be transferred to the main rail of the other track via the shared iron pads, with the main rails providing support. The third substructure mainly includes four rails: a straight main rail 3, a curved main rail 4, a straight guide rail 5, and a curved guide rail 6. Each rail is supported by an iron pad, and wheel loads are transferred to the switch sleepers. In the transmission process, all four rails will simultaneously provide support; in the fourth substructure, the straight guide rail 5 and the curved guide rail 6 share a common pad, and the wheel load acting on the straight or curved guide rail is transmitted to the other guide rail through the shared pad, providing support; in the fifth substructure, the wheel load acts on the center rail (long center rail 8, short center rail 9) and is transmitted through the pad, while the other center rail and the two wing rails 7 will simultaneously provide support; in the sixth substructure, the wheel load acts on the center rail and is transmitted through the iron pad, while the wing rail 7 will provide support.

[0046] In step two, the rail pad is a rubber pad laid under the rail, and there is an iron pad under the rail pad. The plate pad is a rubber pad under the iron pad.

[0047] In step three, the dynamic response values ​​of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are calculated based on the vehicle-turnout coupled dynamics model.

[0048] In step three, the weighting coefficients for wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are 0.7, 0.4, 0.4, 0.6, and 0.6, respectively.

[0049] In engineering, the bending stiffness of the rails, the spacers, the under-rail rubber pads, the under-slab rubber pads, and the track bed support stiffness can all affect the overall stiffness of the track structure. Among these influencing factors, the rails and spacers are required for the turnout structure design and cannot be changed arbitrarily; the under-rail rubber pads are the guarantee of the torsional stiffness of the fastening system and cannot be used with lower stiffness; changing the track bed stiffness is neither economical nor easy to achieve, while the stiffness of the under-slab rubber pads has a large variable range and is easy to achieve. Therefore, by reasonably setting the stiffness of the under-slab pads (under-slab rubber pads), the track stiffness in the turnout area can be uniformly varied.

[0050] Specific application examples:

[0051] To adapt to the lightweight design of 400 km / h trains, based on the mechanical relationship between different substructures of the turnout and combined with the track stiffness homogenization design theory of the turnout area considering dynamic parameter sensitivity analysis, and taking the existing under-rail rubber pad stiffness of 25 kN / mm as a condition, the dynamic parameters under different track stiffnesses were calculated using vehicle-turnout coupled dynamics. The function values ​​under different under-rail rubber pad stiffness matching were studied. The smaller the function value, the smaller the corresponding comprehensive dynamic response of the track. The under-rail rubber pad stiffness corresponding to the smallest function value was taken as the optimized stiffness, and the stiffness distribution law of different substructures of the optimized turnout track was obtained.

[0052] The overall stiffness distribution law of the 400 high-speed turnout track, obtained through the above methods, is shown in Table 1 and Appendix 2 below. Figure 8 As shown:

[0053] Table 1400 High-Speed ​​Turnout Track Stiffness Distribution

[0054]

[0055] According to the optimization of this invention: the lateral stiffness ride comfort is improved: the maximum stiffness ratio is reduced from 2.561 to 1.926; the longitudinal stiffness ride comfort is improved: the maximum deflection rate is reduced from 0.345 mm / m to 0.142 mm / m.

[0056] This solution provides a method for accurately calculating the stiffness of each section in the turnout area, providing data support for subsequent solutions to achieve uniform stiffness in the turnout area. This technology adopts a multi-objective optimization design method, with the dynamic response of the turnout area, track stiffness matching, and uniform stiffness distribution as objectives. It comprehensively considers the interaction mechanism of multiple components such as the internal spacer and shared long pad, as well as the superelastic material properties of the under-plate rubber pad, and achieves the overall uniform stiffness design of the 400 high-speed turnout.

[0057] The apparatus and methods disclosed in the embodiments are described in a relatively simple manner since they correspond to the methods disclosed in the embodiments. For relevant details, please refer to the description in the method section.

[0058] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A design method for track stiffness distribution and homogenization in turnout areas, characterized in that, Includes the following steps: Step 1: Divide the turnout track section. Based on the uneven distribution of the overall stiffness of the turnout and its structural characteristics, the turnout is divided into six substructures from one end to the other. The area between adjacent substructures is the turnout track section. The track components in different turnout track sections have different stiffness variation ranges. Step Two: Both the rail pad and the slab pad are elastic components, directly affecting the stiffness variation of the turnout track. When designing for uniform turnout track stiffness, the matching of turnout track stiffness and dynamic response is the research objective. The matching of dynamic response is affected by the sensitivity of dynamic parameters, which include five parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration. The ratio of the rate of change of a dynamic parameter to the rate of change of the corresponding overall track stiffness is defined as the sensitivity coefficient of that dynamic parameter. In Equation 1, K1 is the overall track stiffness before optimization, K2 is the overall track stiffness after optimization, D1 is the selected dynamic parameters before optimization, and D2 is the selected dynamic parameters after optimization. All five dynamic parameters are processed according to Equation 1. Step 3: Calculate the sensitivity coefficients of the changes in the stiffness of the rail pad and the changes in the stiffness of the under-slab pad to the dynamic parameters according to Formula 1. Obtain the average sensitivity coefficient of each dynamic parameter in the corresponding track interval based on the aforementioned sensitivity coefficients. Since the calculated wheel-rail dynamic effect is a time history curve, a sensitivity coefficient can be calculated at each moment. Therefore, the average value of the corresponding track interval is used as the subsequent evaluation index. Considering that the sensitivity of each dynamic parameter to the stiffness of the rail pad and the under-slab pad is different, a function is constructed with the goal of minimizing the overall dynamic response of the track. An evaluation formula f for the optimal overall track stiffness is proposed. Under the condition of optimal overall track stiffness, the peak value of the dynamic response of the train passing through the turnout is minimized. In Equation 2 and These are the sensitivity coefficients of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration to changes in track component stiffness, respectively. i=1 represents the stiffness of the under-rail rubber pad; i=2 represents the stiffness of the under-slab rubber pad, N. r U r U g A r A g These are the standard values ​​of five dynamic parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration; β knr β kur β kug β kar and β kag These represent the weighting coefficients for wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively; N br U br U bg A br and A bg These represent the calculated dynamic response values ​​of the corresponding parameters: wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration, respectively. Step 4: After calculating the optimal value of the overall stiffness of the turnout track according to Formula 2, calculate the stiffness distribution law of the rail pad and the plate pad under different turnout track sections based on this value.

2. The design method for track stiffness distribution and homogenization in turnout areas according to claim 1, characterized in that, In step one, the six substructures include a first substructure, a second substructure, a third substructure, a fourth substructure, a fifth substructure, and a sixth substructure. The first substructure corresponds to the part in front of the tip of the switch rail, the second substructure corresponds to the switch part, the third substructure corresponds to the turnout track guide curve part, the fourth substructure corresponds to the part of the guide curve near the end of the frog where the two guide rails share a pad, the fifth substructure corresponds to the part of the frog where the two wing rails and the two frog rails share a pad, and the sixth substructure corresponds to the part of the turnout transition after the turnout, where the center rail and the wing rails share a pad.

3. The design method for track stiffness distribution and homogenization in turnout areas according to claim 2, characterized in that, The first substructure consists of a main rail, a rail base plate, fasteners, a steel base plate, a plate base plate, and sleepers. The second substructure consists of a switch rail, a main rail, and a shared steel base plate. When wheel load is applied to the switch rail, it can be transferred to the main rail of the other track through the shared steel base plate, and the main rail provides support. The third substructure mainly includes four rails: a straight main rail, a curved main rail, a straight guide rail, and a curved guide rail. Each rail is supported by a steel base plate, and wheel load is transferred through the sleepers. All four rails provide support simultaneously. In the fourth substructure, the straight guide rail and the curved guide rail share a base plate. Wheel load applied to the straight or curved guide rail is transferred to the other guide rail through the shared base plate, providing support. In the fifth substructure, wheel load is applied to the center rail and transferred through the base plate. The other center rail and the two wing rails provide support simultaneously. In the sixth substructure, wheel load is applied to the center rail and transferred through the steel base plate. The wing rails provide support.

4. The design method for track stiffness distribution and homogenization in turnout areas according to claim 1, characterized in that, In step two, the rail pad is a rubber pad laid under the rail, and there is an iron pad under the rail pad. The plate pad is a rubber pad under the iron pad.

5. The design method for track stiffness distribution and homogenization in turnout areas according to claim 1, characterized in that, In step three, the dynamic response values ​​of wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are calculated based on the vehicle-turnout coupled dynamics model.

6. The design method for track stiffness distribution and homogenization in turnout areas according to claim 1, characterized in that, In step three, the weighting coefficients for wheel-rail vertical force, rail vertical displacement, track slab vertical displacement, rail vertical acceleration, and track slab vertical acceleration are 0.7, 0.4, 0.4, 0.6, and 0.6, respectively.

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