Railway line flat and vertical section design method based on full-speed-domain wheel-rail interface characteristics

Abstract

The invention discloses a railway line flat and vertical section design method based on full-speed-domain wheel-rail interface characteristics. The method comprises the following steps: establishing a full-speed-domain wheel-rail creep characteristic database; constructing a target function; establishing a multi-target coupling optimization model based on the line geometric parameters, the wheel-rail microscopic contact behaviors and the passenger comfort indexes; and inputting an objective function into the multi-objective coupling optimization model, and outputting an optimal line flat and vertical section design scheme meeting the requirements of the objective function. The invention provides a railway line flat and vertical section design method based on full-speed-domain wheel-rail interface characteristics, and aims to solve the problem that an existing simulation design method is difficult to realize collaborative optimization of line geometric parameters, wheel-rail interface characteristics and passenger comfort under complex working conditions. The design scientificity and the operation adaptability of railway line parameters are improved, and the purposes of being more practical, more reliable and capable of supporting use of the passenger transport high-speed railway under the complex working condition are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit line design, in particular to a railway line plane and longitudinal section design method based on wheel-rail interface characteristics in full speed domain, which is particularly suitable for the geometric optimization design of high-speed railway and complex working condition line. BACKGROUND

[0002] The design parameters of railway line plane and longitudinal section in China are usually studied and determined by using driving dynamics method. This method cannot accurately reflect the vibration characteristics of the vehicle when running on the curve because it does not consider the coupling effect between the vehicle, the line structure and each other, and there is a deviation in the dynamic running safety and passenger comfort under the actual driving conditions. Therefore, this method has certain drawbacks.

[0003] In recent years, with the continuous development of simulation technology, there are existing technologies that rely on simulation technology to carry out the design of rail transit plane and longitudinal section. However, such existing technologies mainly focus on the correlation analysis of line parameters and vehicle running parameters (such as dynamic performance and safety), and often fail to take passenger comfort as the core design target or establish an effective coupling model of wheel-rail interface characteristics. This leads to the difficulty of fully guaranteeing the high-standard passenger comfort experience under the conditions of long and large slopes and complex curve lines. In summary, the existing technology is difficult to realize the collaborative optimization of line geometric parameters, wheel-rail interface characteristics and passenger comfort under complex working conditions. SUMMARY

[0004] The present application provides a railway line plane and longitudinal section design method based on wheel-rail interface characteristics in full speed domain, to solve the problem that the existing simulation design method is difficult to realize the collaborative optimization of line geometric parameters, wheel-rail interface characteristics and passenger comfort under complex working conditions, to realize the improvement of the design scientificity and running adaptability of railway line parameters, and to achieve the purpose of obtaining a more practical, reliable and able to support the use of passenger high-speed railway under complex working conditions.

[0005] The present application is realized by the following technical scheme:

[0006] A railway line plane and longitudinal section design method based on wheel-rail interface characteristics in full speed domain, comprising the following steps:

[0007] S1, establishing a wheel-rail creep characteristic database in full speed domain;

[0008] S2, constructing an objective function;

[0009] S3, based on line geometric parameters, wheel-rail micro-contact behavior and passenger comfort indicators, establishing a multi-objective coupling optimization model;

[0010] S4, input the objective function into the multi-objective coupling optimization model, and output an optimal line plan and profile design scheme meeting the requirements of the objective function.

[0011] In view of the fact that the railway line designed based on the simulation technology in the prior art fails to fully consider key factors such as micro behaviors of a wheel-rail interface and passenger comfort, and is difficult to realize collaborative optimization of line geometric parameters, wheel-rail interface characteristics and passenger comfort under complex working conditions, the present application provides a railway line plan and profile design method based on wheel-rail interface characteristics in a full speed range. The method first establishes a wheel-rail creep characteristic database in a full speed range, wherein the full speed range refers to all speed ranges that can be covered by a train during operation, as understood by those skilled in the art. Then, the method establishes a required objective function, and establishes a multi-objective coupling optimization model. Based on the multi-objective coupling optimization model and the objective function, an optimal line plan and profile design scheme is obtained.

[0012] The multi-objective coupling optimization model in the present application comprehensively considers three dimensions of line geometric parameters, wheel-rail micro contact behaviors and passenger comfort indicators, and the obtained design result is more practical, more consistent with actual working conditions, and more capable of supporting use of passenger high-speed railways under complex working conditions, thereby improving comprehensive adaptability and optimization level of line design under complex working conditions.

[0013] Further, the wheel-rail creep characteristic database includes any one or more of the following data under different line working conditions: contact patch shape data, creep force distribution data, wheel-rail contact stress data and wheel-rail wear data.

[0014] Further, the method for establishing the wheel-rail creep characteristic database in a full speed range includes:

[0015] S11, a wheel-rail contact creep characteristic curve under different speeds and different dry and wet track surface states is measured by a high-speed wheel-rail rolling test bed;

[0016] S12, a wheelset-rail finite element model is established; based on the wheel-rail contact creep characteristic curve and the wheelset-rail finite element model, a vehicle-line dynamics simulation model is established;

[0017] S13, based on the vehicle-line dynamics simulation model, contact patch shape data, creep force distribution data and wheel-rail contact stress data under different line working conditions are obtained;

[0018] S14, a wheel-rail multi-body dynamics-abrasion coupling simulation model is established, and wheel-rail wear data under different line working conditions are obtained;

[0019] S15, wheel-rail wear conditions of an actual operation line are tracked and measured, and the wheel-rail wear data are dynamically updated.

[0020] In the scheme, the wheel-rail wear data is dynamically updated according to the data obtained in the actual operation process. In addition, the wheel-rail contact creep characteristic curve and the vehicle-line dynamics simulation model are contents that can be obtained according to the existing technology, and details are not repeated here.

[0021] Further, the constructed objective function includes:

[0022] ;

[0023] In the formula: minF represents the objective function; f1 is the contact patch area coefficient of variation; w1 is the contact patch area coefficient of variation weight; f2 is the creep force unevenness; w2 is the creep force unevenness weight; f3 is the maximum contact stress ratio; w3 is the maximum contact stress ratio weight; f4 is the wear index; w4 is the wear index weight; f5 is the first passenger comfort index; w5 is the first passenger comfort index weight; f6 is the second passenger comfort index; and w6 is the second passenger comfort index weight.

[0024] It can be seen that the objective function in the scheme is coupled and optimized by the wheel-rail micro contact index and the passenger comfort index, which can meet the precise design requirements under complex working conditions such as long and large slope longitudinal section and complex curve line, and at the same time ensure that the designed line is relatively friendly to passenger comfort.

[0025] Further, in the objective function:

[0026] ;

[0027] ;

[0028] ;

[0029] ;

[0030] In the formula: σ(A) is the standard deviation of the contact patch area set; μ(A) is the mean of the contact patch area set; F x is the longitudinal creep force; F y is the transverse creep force; F z is the normal force; σ max is the maximum stress of the contact area; [σ] is the allowable contact stress of the steel rail material; ξ x is the longitudinal creep rate; ξ y is the transverse creep rate.

[0031] ;

[0032] ;

[0033] In the formula: a yis the lateral vibration acceleration of the vehicle body; a z is the vertical vibration acceleration of the vehicle body; f is the vibration frequency, and F(f) is the vibration frequency correction coefficient.

[0034] Each index parameter can be obtained through simulation or actual measurement, and is not specifically limited herein.

[0035] Further, the multi-objective coupling optimization model comprises:

[0036] a mapping relationship between the track geometric parameters and wheel-rail microscopic contact behavior, an influence model of the wheel-rail microscopic contact behavior on passenger comfort, and an adjustment model of passenger comfort feedback on the track geometric parameters.

[0037] The multi-objective coupling optimization model in the present application can be implemented using any existing model. However, in a traditional railway line plan and profile design model, only the correlation between the track parameters and the vehicle operation parameters is considered. In the present application, the following three design criteria are defined in the model: a mapping relationship between the track geometric parameters and wheel-rail microscopic contact behavior, an influence model of the wheel-rail microscopic contact behavior on passenger comfort, and an adjustment model of passenger comfort feedback on the track geometric parameters. Through these three design criteria, the dynamic correlation between the design result and passenger comfort can be ensured, and thus the actual usability of the designed railway line is improved.

[0038] Further, the mapping relationship between the track geometric parameters and the wheel-rail microscopic contact behavior is obtained by the following method:

[0039] A response model of the track geometric parameters and the wheel-rail contact parameters is constructed through multi-body dynamics simulation;

[0040] A sensitivity analysis method is used to determine the key track geometric influence parameters that affect the wheel-rail contact parameters, which are defined as sensitive parameters;

[0041] A parameter coupling database is established to store the data corresponding to the matched wheel-rail microscopic contact behavior under different combinations of the sensitive parameters;

[0042] An interpolation operation is performed on the parameter coupling database to obtain the mapping relationship between the track geometric parameters and the wheel-rail microscopic contact behavior.

[0043] In the present application, the sensitive parameters are determined based on the sensitivity analysis method, and the data representing the wheel-rail microscopic contact behavior corresponding to different combinations of the sensitive parameters are stored to obtain the parameter coupling database. Then, the mapping relationship between the track geometric parameters and the wheel-rail microscopic contact behavior can be obtained based on the interpolation operation.

[0044] Further, the adjustment model of passenger comfort feedback on the track geometric parameters is obtained by the following method:

[0045] According to the existing line plan and profile design scheme, the vehicle body vibration data is obtained through simulation or test, and the Sperling index is calculated;

[0046] If the Sperling index is out of limit, the parameter adjustment strategy is triggered, and the line plan and profile design scheme is adjusted;

[0047] The wheel-rail contact state corresponding to the adjusted line plan and profile design scheme is verified until the Sperling index meets the preset requirement.

[0048] In the scheme, the adjustment model of passenger comfort feedback on line geometric parameters is established based on the Sperling index, which provides strong constraint boundary conditions for the multi-objective coupling optimization model, and further improves the rationality of line design and passenger comfort. The Sperling index is a term in the art and is not repeated here.

[0049] Further, step S4 specifically comprises:

[0050] S41, obtaining initial line geometric parameters;

[0051] S42, performing micro contact behavior simulation and passenger comfort index calculation on the initial line geometric parameters based on a wheel-rail creep characteristic database;

[0052] S43, inputting the objective function into the multi-objective coupling optimization model, and constantly optimizing the line geometric parameters according to the objective function, iterating until the optimal solution is output.

[0053] Step S4 is to constantly iterate the designed line to output the optimal line plan and profile design scheme. The initial line geometric parameters are obtained based on the initial designed track line.

[0054] Compared with the prior art, the present application has at least the following advantages and beneficial effects:

[0055] 1. The railway line plan and profile design method based on the wheel-rail interface characteristics in the full speed domain, wherein the multi-objective coupling optimization model comprehensively considers the line geometric parameters, wheel-rail micro contact behavior and passenger comfort index, the obtained design result is more practical and more suitable for actual working conditions, and can better support the use of passenger high-speed railway under complex working conditions, and improve the comprehensive adaptability and optimization level of line design under complex working conditions.

[0056] 2. The railway line horizontal and vertical section design method based on the wheel-rail interface characteristics in the full speed domain, wherein the objective function is coupled and optimized by the wheel-rail microscopic contact index and the passenger comfort index, can meet the accurate design requirements under complex working conditions such as long and large slope vertical section and complex curve line, and ensure that the designed line is relatively friendly to passenger comfort.

[0057] 3. The railway line horizontal and vertical section design method based on the wheel-rail interface characteristics in the full speed domain, through three-dimensional design criteria, can ensure the dynamic correlation between the design result and the passenger comfort, and further improve the rationality and operation quality of the designed railway line.

[0058] 4. The existing railway line horizontal and vertical section design method mainly relies on macroscopic dynamics indexes (such as derailment coefficient and wheel load reduction rate) and empirical formula, and the microscopic behavior of the wheel-rail interface (such as contact spot shape, creep force distribution and contact stress) is not considered enough, and is usually only used for later checking or passive adjustment. The present application creatively takes the wheel-rail microscopic contact characteristics (contact spot, creep, stress and wear) as the core optimization target, directly drives the line geometric parameter design, realizes the whole-chain optimization from the microscopic to the macroscopic, and significantly improves the scientificity and accuracy of the design.

[0059] 5. The railway line horizontal and vertical section design method based on the wheel-rail interface characteristics in the full speed domain, by constructing a full-speed wheel-rail creep characteristic database, the dry and wet track surface state, different running speeds and various working conditions are covered. The database can be supported by both measured data and simulation model, can adapt to a wide range of application scenarios from medium and low speed to high speed railway, and has good scalability and applicability.

[0060] 6. The railway line horizontal and vertical section design method based on the wheel-rail interface characteristics in the full speed domain, can be compatible with new line and existing line reconstruction scenarios, can be used as the basis for preliminary design of new line, and can also be used for adaptability evaluation and design adjustment of existing line, serving the whole life cycle performance optimization of railway. DETAILED DESCRIPTION

[0061] The drawings described herein are used to provide further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0062] Figure 1 It is a flowchart of the specific embodiments of the present application. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application is further described in detail below in combination with embodiments and drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not constitute a limitation on the present application.

[0064] Embodiment 1:

[0065] As Figure 1 shown in a railway line horizontal and vertical section design method based on wheel-rail interface characteristics in full speed domain, comprising the following steps:

[0066] Step S1, establishing a wheel-rail creep characteristic database in full speed domain; the wheel-rail creep characteristic database includes contact patch shape data, creep force distribution data, wheel-rail contact stress data and wheel-rail wear data under different line conditions.

[0067] The full speed domain in this embodiment is 40km / h~400km / h.

[0068] Specifically, in this embodiment, the wheel-rail creep characteristic database in full speed domain is established by the following method:

[0069] S11, through a high-speed wheel-rail rolling test bench, the wheel-rail contact creep characteristic curve under different speeds and different dry and wet rail surface states is measured;

[0070] S12, establishing a wheelset-rail finite element model; based on the wheel-rail contact creep characteristic curve and the wheelset-rail finite element model, a vehicle-line dynamics simulation model is established;

[0071] S13, based on the vehicle-line dynamics simulation model, the contact patch shape data, the creep force distribution data and the wheel-rail contact stress data under different line conditions are obtained;

[0072] S14, based on the Archard wear model, a wheel-rail multi-body dynamics-wear coupling simulation model is established to obtain the wheel-rail wear data under different line conditions;

[0073] S15, tracking and measuring the wheel-rail wear condition of the actual operation line to dynamically update the wheel-rail wear data.

[0074] Step S2, constructing a target function, the expression is:

[0075] ;

[0076] In the formula: minF represents the target function; f1 is the contact patch area variation coefficient; w1 is the contact patch area variation coefficient weight; f2 is the creep force unevenness; w2 is the creep force unevenness weight; f3 is the maximum contact stress ratio; w3 is the maximum contact stress ratio weight; f4 is the wear index; w4 is the wear index weight; f5 is the first passenger comfort index; w5 is the first passenger comfort index weight; f6 is the second passenger comfort index; w6 is the second passenger comfort index weight. The values of w1~w6 can be adaptively adjusted according to the actual working condition.

[0077] in:

[0078] ;

[0079] ;

[0080] ;

[0081] ;

[0082] ;

[0083] ;

[0084] In the formula: σ(A) is the standard deviation of the set of contact patch areas; μ(A) is the mean of the set of contact patch areas; F x For longitudinal creep force; F y For lateral creep force; F z Normal force; σ max [σ] represents the maximum stress in the contact area; [σ] represents the allowable contact stress of the rail material; ξ x ξ represents longitudinal creep rate; y This refers to the lateral creep rate. y a is the lateral vibration acceleration of the vehicle body; z denoted as , where is the vertical vibration acceleration of the vehicle body; f is the vibration frequency, and F(f) is the vibration frequency correction coefficient.

[0085] Step S3: Based on the track geometry parameters, wheel-rail micro-contact behavior, and passenger comfort index, establish a multi-objective coupled optimization model;

[0086] Step S4: Input the objective function into the multi-objective coupled optimization model, and output the optimal horizontal and vertical profile design scheme that satisfies the objective function requirements. Specifically:

[0087] S41. Input the objective function into the multi-objective coupled optimization model to generate initial line geometric parameters;

[0088] S42. Based on the wheel-rail creep characteristic database, perform microscopic contact behavior simulation and passenger comfort index calculation on the initial track geometry parameters; specifically including:

[0089] I. Simulation process of microscopic contact behavior:

[0090] (1) Input of initial line geometric parameters;

[0091] The geometric parameters of the initial design route include: horizontal curve radius, superelevation, transition curve length, vertical curve radius, gradient, and slope length.

[0092] (2) Database parameter matching and interpolation calculation;

[0093] Using the initial track geometry parameters as independent variables, the matching micro-contact behavior data is extracted by interpolating or fitting the wheel-rail creep characteristic database. This data mainly includes: contact patch morphology, creep force distribution, contact stress, and wear index.

[0094] (3) Coupled modeling of finite element method and multibody dynamics;

[0095] If the database accuracy is insufficient, real-time calculations can be performed using a wheel-rail model combined with a vehicle track dynamics model to correct database interpolation errors.

[0096] (4) Normalization of micro-indicators and evaluation of objective function;

[0097] The above contact parameters, after being normalized, are used as inputs to the objective function and participate in subsequent weight combinations and line evaluation.

[0098] II. Calculation process of passenger comfort index:

[0099] (1) Acquisition of vehicle system dynamic response

[0100] The initial track geometry parameters are input into the vehicle dynamics simulation model to simulate the train's running response on the track and obtain the time history data of the car body acceleration, such as lateral acceleration and vertical acceleration.

[0101] (2) Calculation of passenger comfort index

[0102] Frequency domain analysis was performed on the acquired acceleration data, and the data was corrected according to the frequency weighting function to obtain the frequency weighted acceleration value. The lateral and vertical sperling indices were then calculated.

[0103] (3) Comfort evaluation and objective function feedback

[0104] The obtained comfort index is used as part of the objective function to participate in the optimization process of the line geometry parameters.

[0105] S43. Optimize the line geometry parameters continuously according to the objective function, iterating until the optimal solution is output.

[0106] Example 2:

[0107] A method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, building upon Example 1.

[0108] The established multi-objective coupled optimization model includes the following three dimensions of correlation mechanisms:

[0109] The first dimension: the mapping relationship between track geometry parameters and wheel-rail micro-contact behavior;

[0110] The second dimension: a model of the impact of wheel-rail micro-contact behavior on passenger comfort;

[0111] The third dimension: the adjustment model of line geometry parameters based on passenger comfort feedback.

[0112] In a more preferred embodiment, the mapping relationship between the track geometry parameters and the wheel-rail micro-contact behavior is obtained by the following method:

[0113] Through multibody dynamics simulation, the geometric parameters of the line (such as curve radius R, superelevation h, curve length L, gradient i, and vertical curve radius R) are constructed. v Length of slope segment L v The response model of wheel-rail contact parameters (contact patch area, creep force, contact stress, etc.) is described below; this response model can be expressed as:

[0114] Where v is the train speed.

[0115] Sensitivity analysis was used to determine the critical geometric influence parameters affecting wheel-rail contact parameters, which were defined as sensitive parameters.

[0116] Establish a parameter coupling database to store data corresponding to the wheel-rail micro-contact behavior under different combinations of the aforementioned sensitive parameters.

[0117] Interpolation operations are performed on the parameter coupling database to obtain the mapping relationship between the track geometry parameters and the wheel-rail micro-contact behavior.

[0118] In a more preferred embodiment, the influence model of wheel-rail micro-contact behavior on passenger comfort is obtained by the following method: by constructing a "contact mechanics-vibration transmission chain" to reveal the intrinsic relationship between wheel-rail interface characteristics and passenger comfort; and by using the vibration transmission chain of contact mechanics and vehicle response, namely "wheel-rail interface micro-characteristics → wheelset lateral force → frame vibration acceleration → vehicle body vibration response", the accurate prediction of wheel-rail micro-behavior on macro-comfort is achieved based on wheel-rail contact mechanics and vehicle dynamics.

[0119] In a more preferred embodiment, the passenger comfort feedback adjustment model for the line geometry parameters is obtained through the following method: based on the existing line horizontal and vertical profile design scheme, vehicle vibration data is obtained and the Sperling index is calculated through simulation or experiment; if the Sperling index exceeds the limit, the parameter adjustment strategy is triggered to adjust the line horizontal and vertical profile design scheme; the wheel-rail contact state corresponding to the adjusted line horizontal and vertical profile design scheme is verified until the Sperling index meets the preset requirements.

[0120] 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.

[0121] 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 designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, characterized in that, Includes the following steps: S1. Establish a database of wheel-rail creep characteristics across the entire speed domain; S2. Construct the objective function; S3. Based on the track geometry parameters, wheel-rail micro-contact behavior, and passenger comfort indicators, a multi-objective coupled optimization model is established. S4. Input the objective function into the multi-objective coupled optimization model and output the optimal horizontal and vertical profile design scheme that meets the requirements of the objective function.

2. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 1, is characterized in that... The wheel-rail creep characteristic database includes any one or more of the following data under different track conditions: contact patch morphology data, creep force distribution data, wheel-rail contact stress data, and wheel-rail wear data.

3. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 1, is characterized in that... The method for establishing a full-speed-domain wheel-rail creep characteristic database includes: S11. The wheel-rail contact creep characteristic curves under different speeds and different dry and wet rail surface conditions were measured by using a high-speed wheel-rail rolling test bench. S12. Establish a wheelset-track finite element model; based on the wheel-track contact creep characteristic curve and the wheelset-track finite element model, establish a vehicle-track dynamics simulation model; S13. Based on the aforementioned vehicle track dynamics simulation model, obtain contact patch morphology data, creep force distribution data, and wheel-rail contact stress data under different track conditions; S14. Establish a multibody dynamics-wear coupling simulation model of wheel and rail to obtain wheel and rail wear data under different track conditions; S15. Track and measure the wheel and rail wear of the actual operating line, and dynamically update the wheel and rail wear data.

4. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 1, is characterized in that... The objective function includes: ； In the formula: minF represents the objective function; f1 is the coefficient of variation of the contact patch area; w1 is the weight of the coefficient of variation of the contact patch area; f2 is the non-uniformity of creep force; w2 is the weight of the non-uniformity of creep force; f3 is the maximum contact stress ratio; w3 is the weight of the maximum contact stress ratio; f4 is the wear index; w4 is the weight of the wear index; f5 is the first passenger comfort index; w5 is the weight of the first passenger comfort index; f6 is the second passenger comfort index; w6 is the weight of the second passenger comfort index.

5. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 4, is characterized in that... In the objective function: ； ； ； ； In the formula: σ(A) is the standard deviation of the set of contact patch areas; μ(A) is the mean of the set of contact patch areas; F x For longitudinal creep force; F y For lateral creep force; F z Normal force; σ max [σ] represents the maximum stress in the contact area; [σ] represents the allowable contact stress of the rail material; ξ x ξ represents the longitudinal creep rate; y This refers to the lateral creep rate.

6. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 4, is characterized in that... In the objective function: ； ； In the formula: a y a is the lateral vibration acceleration of the vehicle body; z denoted as , where is the vertical vibration acceleration of the vehicle body; f is the vibration frequency, and F(f) is the vibration frequency correction coefficient.

7. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 1, is characterized in that... The multi-objective coupled optimization model includes: The mapping relationship between track geometry parameters and wheel-rail micro-contact behavior, the influence model of wheel-rail micro-contact behavior on passenger comfort, and the adjustment model of track geometry parameters by passenger comfort feedback.

8. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 7, is characterized in that... The mapping relationship between the track geometry parameters and the wheel-rail micro-contact behavior is obtained through the following method: Response models of track geometry parameters and wheel-rail contact parameters are constructed through multibody dynamics simulation. Sensitivity analysis was used to determine the critical geometric influence parameters affecting wheel-rail contact parameters, which were defined as sensitive parameters. Establish a parameter coupling database to store data corresponding to the wheel-rail micro-contact behavior under different combinations of the aforementioned sensitive parameters. Interpolation operations are performed on the parameter coupling database to obtain the mapping relationship between the track geometry parameters and the wheel-rail micro-contact behavior.

9. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 7, is characterized in that... The passenger comfort feedback adjustment model for the line geometry parameters was obtained through the following method: Based on the existing horizontal and vertical profile design schemes of the line, obtain vehicle vibration data and calculate the Sperling index through simulation or experimentation. If the Sperling index exceeds the limit, the parameter adjustment strategy is triggered, and the horizontal and vertical profile design scheme of the line is adjusted. Verify the wheel-rail contact state corresponding to the adjusted horizontal and vertical profile design scheme of the line until the Sperling index meets the preset requirements.

10. The method for designing the horizontal and vertical profiles of railway lines based on the wheel-rail interface characteristics across the entire velocity domain, as described in claim 1, is characterized in that... Step S4 specifically includes: S41. Obtain the initial line geometry parameters; S42. Based on the wheel-rail creep characteristic database, perform microscopic contact behavior simulation and passenger comfort index calculation on the initial track geometric parameters; S43. Input the objective function into the multi-objective coupled optimization model, continuously optimize the line geometric parameters according to the objective function, iterate, until the optimal solution is output.

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