Three-dimensional transient wheel-rail contact simulation method and system for accelerated conditions

Abstract

The embodiment of the application provides a kind of accelerated state three-dimensional transient wheel-rail contact simulation method and system, belong to railway vehicle dynamics technical field.The method comprises: based on high-speed railway wheel-rail basic parameter construction high-speed wheel-rail finite element model, and to high-speed wheel-rail finite element model executes static force condition loading, obtains the finite element model under static state;To the finite element model under static state executes dynamic condition loading, to obtain the finite element model with rotational inertia state;To the finite element model with rotational inertia state executes explicit acceleration loading, obtains the finite element model under steady state after reaching target speed;Based on the finite element model under steady state, to the target working condition currently to be simulated executes transient dynamic solution, outputs the wheel-rail dynamics response parameter set of target working condition.The application scheme ensures that the output wheel-rail dynamics response parameter set truly reflects the dynamics behavior under high-speed working condition, provides reliable data basis for engineering application.

Description

Technical Field

[0001] The present invention relates to the technical field of railway vehicle dynamics, and in particular to a three-dimensional transient wheel-rail contact simulation method in an accelerated state and a three-dimensional transient wheel-rail contact simulation system in an accelerated state. Background Art

[0002] With the development of high-speed railway technology and the continuous increase in train operating speeds, higher requirements are being placed on the simulation and analysis of the dynamic characteristics of wheel-rail interaction. Three-dimensional transient wheel-rail contact modeling and dynamic analysis have become an important tool for studying the coupled dynamics of high-speed railway vehicles and tracks. Finite element modeling and numerical analysis can effectively analyze the contact forces, track structural stresses, and dynamic response of the wheel-rail system under high-speed conditions. However, existing high-speed wheel-rail contact simulation solutions still have certain shortcomings in terms of initial loading conditions and modeling dynamic processes, which affect simulation accuracy and engineering applicability.

[0003] Existing solutions generally establish the initial rotational state of the wheelset by directly applying a target velocity or initial angular velocity. This type of loading, in the absence of a natural dynamic transition process, can easily introduce numerical shock or simulated initial perturbations. High-speed wheel-rail systems have large wheelsets with significant rotational inertia and centrifugal forces. If the initial state is not fully consistent with the physical process, simulation calculations may experience sudden changes in contact forces, abnormal node stresses, or sudden energy jumps, leading to poor numerical convergence and insufficiently stable results.

[0004] Existing technologies generally lack disturbance monitoring and control mechanisms for high-speed wheel-rail simulation loading processes. Some solutions lack real-time monitoring and feedback control of wheel-rail contact status, dynamic response, and energy changes during the acceleration phase. This leads to the accumulation of numerical disturbances during the acceleration loading process, making it difficult to detect and suppress simulation anomalies in a timely manner, affecting the reliability of the final dynamic results and engineering usability. This is particularly prominent under high-speed conditions, where the dynamic behavior of the wheel-rail system is more sensitive and requires higher stability and accuracy in the simulation process.

[0005] Therefore, for high-speed wheel-rail conditions, how to achieve a natural and smooth transition of the dynamic process during modeling and loading, reduce the initial disturbance of the simulation, and effectively monitor and control the acceleration process are key issues that urgently need to be improved in existing technologies. Summary of the Invention

[0006] The purpose of the embodiments of the present invention is to provide a three-dimensional transient wheel-rail contact simulation method and system in an accelerated state, so as to at least solve the problems in existing high-speed wheel-rail simulations that initial state loading is prone to introduce disturbances and the acceleration process lacks disturbance monitoring and control.

[0007] In order to achieve the above object, the application provides a three-dimensional transient wheel-rail contact simulation method for accelerated state, which comprises the following steps: constructing a high-speed wheel-rail finite element model based on high-speed wheel-rail basic parameters, and performing static working condition loading on the high-speed wheel-rail finite element model to obtain a finite element model in a static state; performing dynamic working condition loading on the finite element model in the static state to obtain a finite element model with rotational inertia state; performing explicit accelerated loading on the finite element model with rotational inertia state to obtain a finite element model in a steady state after reaching a target speed; performing transient dynamic solving on a target working condition to be simulated based on the finite element model in the steady state, and outputting a wheel-rail dynamic response parameter set of the target working condition.

[0008] Optionally, the high-speed wheel-rail basic parameters comprise structural parameters, wheel-rail contact geometric parameters and wheel-rail material mechanical properties of a wheel-rail system; the high-speed wheel-rail finite element model is constructed based on the high-speed wheel-rail basic parameters, which comprises the following steps: establishing a wheelset dynamic unit model and a track bearing unit model based on the structural parameters of the wheel-rail system, respectively; the wheelset dynamic unit model is used to describe wheelset dynamic parameters; the track bearing unit model is used to describe track dynamic parameters; a wheel-rail contact unit model is constructed based on the wheelset dynamic unit model and the track bearing unit model to determine contact dynamic parameters between the wheelset and the track; and the high-speed wheel-rail finite element model is obtained by coupling the wheelset dynamic unit model, the track bearing unit model and the wheel-rail contact unit model.

[0009] Optionally, the static working condition loading is performed on the high-speed wheel-rail finite element model to obtain the finite element model in the static state, which comprises the following steps: applying vertical gravity load of corresponding wheelset and spring mass to the wheelset dynamic unit model; applying support boundary constraint to the track bearing unit model; performing static balance solving on the high-speed wheel-rail finite element model based on the vertical gravity load application result and the support constraint application result to obtain the finite element model in the static state.

[0010] Optionally, the static balance solving is performed on the high-speed wheel-rail finite element model based on the vertical gravity load application result and the support constraint application result to obtain the finite element model in the static state, which comprises the following steps: generating initial static load action of the wheelset dynamic unit model in the static state based on the vertical gravity load application result; limiting boundary node degrees of freedom of the track bearing unit model based on the support constraint application result; performing static balance solving on the high-speed wheel-rail finite element model based on the initial static load action and the boundary node degrees of freedom of the track bearing unit model to obtain static displacement, static stress and wheel-rail contact parameters of each node; and obtaining the finite element model in the static state based on the static displacement, the static stress and the wheel-rail contact parameters of each node.

[0011] Optionally, dynamic working condition loading is performed on the finite element model in the static state to obtain a finite element model with a rotational inertia state, including: based on the finite element model in the static state, applying a traction torque to the axle rotational freedom of the wheelset power unit model, gradually introducing the wheelset rotational inertia through implicit static solution, and forming a natural loading process model in which centrifugal force and wheel-rail contact force develop with rotational speed; based on the natural loading process model, recording the wheel-rail contact parameters and node stress state in real time during the torque loading process, and after the wheelset rotational inertia state converges, obtaining a finite element model with a rotational inertia state based on the wheel-rail contact parameters and node stress state at the corresponding moment.

[0012] Optionally, explicit acceleration loading is performed on the finite element model with the rotational inertia state, and a finite element model in a steady state is obtained after reaching the target speed, including: based on the finite element model in the rotational inertia state, the rotation speed of the wheelset power unit model is gradually increased by an explicit solution algorithm until a preset target speed is reached; during the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are dynamically adjusted; after the wheelset power unit model reaches the target speed and the wheel-rail dynamic response parameters reach a preset standard, the finite element model in the current state is used as the finite element model in a steady state.

[0013] Optionally, during the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are dynamically adjusted, including: based on the wheel-rail dynamic response parameters, the wheelset displacement time history, wheel-rail contact force time history, node stress changes, hourglass energy changes, and internal energy changes of the wheelset power unit model are acquired in real time to determine the disturbance level of the acceleration process; when the disturbance level exceeds a preset threshold, the simulation step size, damping coefficient, and / or acceleration rate in the acceleration control parameters are adjusted, and the disturbance level of the acceleration process is re-determined after the adjustment until the disturbance level of the acceleration process is lower than the preset disturbance threshold, and it is determined that the wheel-rail dynamic response parameters meet the preset standard.

[0014] Optionally, based on the finite element model in a steady state, a transient dynamic solution is performed on the target working condition to be simulated, and a wheel-rail dynamic response parameter set of the target working condition is output, including: obtaining a physical parameter set of the target working condition to be simulated; loading the wheel-rail initial physical state parameter set of the finite element model in a steady state based on the physical parameter set, and constructing a finite element initial state matching the current target working condition; performing a transient dynamic solution based on the finite element initial state, and outputting a wheel-rail dynamic response parameter set in real time for describing the wheel-rail dynamic behavior and energy balance state under the current target working condition.

[0015] Optionally, the physical parameter set of the target working condition to be simulated currently includes: target speed, target track segment geometry, wheel-rail contact initial conditions and external working condition boundary information.

[0016] A second aspect of the present invention provides a three-dimensional transient wheel-rail contact simulation system in an accelerated state, the system comprising: a model construction unit for constructing a high-speed wheel-rail finite element model based on basic parameters of high-speed railway wheels and rails, and performing static working condition loading on the high-speed wheel-rail finite element model to obtain a finite element model in a stationary state; a dynamic loading unit for performing dynamic working condition loading on the finite element model in the stationary state to obtain a finite element model with a rotational inertia state; an accelerated state simulation unit for performing explicit acceleration loading on the finite element model with a rotational inertia state to obtain a finite element model in a steady state after reaching a target speed; and an output unit for performing transient dynamic solution for a target working condition to be simulated based on the finite element model in the steady state, and outputting a wheel-rail dynamic response parameter set of the target working condition.

[0017] Through the above technical solution, the solution of the present invention can establish a dynamic loading path that conforms to physical reality in high-speed wheel-rail simulation, effectively reducing initial disturbances and improving the accuracy of dynamic solutions. By constructing a finite element model based on the basic parameters of high-speed railway wheels and rails and loading the static working condition, physical state consistency is achieved in the static state; dynamic working condition loading gradually introduces the rotational inertia state of the wheelset to avoid sudden disturbances caused by directly applying the target speed; explicit acceleration loading smoothly increases the wheelset speed to the target value while supporting real-time disturbance monitoring and adaptive regulation of acceleration parameters, significantly improving the numerical convergence of the acceleration process; finally, the transient dynamic solution of the target working condition is completed in a stable state, ensuring that the output wheel-rail dynamic response parameter set truly reflects the dynamic behavior under high-speed working conditions, providing a reliable data foundation for engineering applications.

[0018] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0020] Figure 1 This is a flowchart of the steps of a method for simulating three-dimensional transient wheel-rail contact in an accelerated state provided by one embodiment of the present invention;

[0021] Figure 2 This is a comparison chart of vertical wheel-rail force simulation results using a conventional method and the method of the present invention, provided in one embodiment of the present invention;

[0022] Figure 3 This is a comparison chart of the lateral wheel-rail force simulation results of the conventional method and the method of the present invention provided in one embodiment of the present invention;

[0023] Figure 4 It is a system structure diagram of a three-dimensional transient wheel-rail contact simulation system in an accelerated state provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0025] Figure 1 This is a flow chart of a method for simulating three-dimensional transient wheel-rail contact in an accelerated state provided by one embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides a three-dimensional transient wheel-rail contact simulation method in an accelerated state, the method comprising:

[0026] Step S10: constructing a high-speed wheel-rail finite element model based on the basic parameters of the high-speed railway wheel-rail, and performing static working condition loading on the high-speed wheel-rail finite element model to obtain a finite element model in a static state.

[0027] Specifically, the basic parameters of high-speed railway wheels and rails include: structural parameters of the wheel-rail system, wheel-rail contact geometric parameters and mechanical properties of wheel-rail materials; constructing a high-speed wheel-rail finite element model based on the basic parameters of high-speed railway wheels and rails, including: establishing a wheelset power unit model and a track bearing unit model based on the structural parameters of the wheel-rail system; wherein the wheelset power unit model is used to describe the group dynamic parameters of the wheel; the track bearing unit model is used to describe the dynamic parameters of the track; constructing a wheel-rail contact unit model based on the wheelset power unit model and the track bearing unit model to determine the contact dynamic parameters between the wheelset and the track; and obtaining a high-speed wheel-rail finite element model based on the coupling of the wheelset power unit model, the track bearing unit model and the wheel-rail contact unit model.

[0028] Furthermore, static working condition loading is performed on the high-speed wheel-rail finite element model to obtain a finite element model in a static state, including: applying a vertical gravity load corresponding to the wheelset and sprung mass to the wheelset power unit model; applying support boundary constraints to the track bearing unit model; and performing a static equilibrium solution on the high-speed wheel-rail finite element model based on the results of the vertical gravity load application and the support constraint application results to obtain a finite element model in a static state.

[0029] Specifically, a static equilibrium solution is performed on the high-speed wheel-rail finite element model based on the vertical gravity load application results and the support constraint application results to obtain a finite element model in a static state, including: generating an initial static load action of the wheelset power unit model in a static state based on the vertical gravity load application results; limiting the boundary node degrees of freedom of the track bearing unit model based on the support constraint application results; performing a static equilibrium solution on the high-speed wheel-rail finite element model based on the initial static load action and the boundary node degrees of freedom of the track bearing unit model to obtain the static displacement, static stress and wheel-rail contact parameters of each node; and obtaining the finite element model in a static state based on the static displacement, static stress and wheel-rail contact parameters of each node.

[0030] In an embodiment of the present invention, a high-speed wheel-rail finite element model is constructed based on the basic parameters of the high-speed railway wheel-rail, and static working condition loading is performed on the high-speed wheel-rail finite element model to obtain a finite element model in a static state. During the specific implementation process, clear modeling and solution rules should be followed to ensure that the established high-speed wheel-rail finite element model can truly, completely and stably express the physical response state of the wheel-rail system in a static state. In this solution, the basic parameters of the high-speed railway wheel-rail serve as the input basis for model construction, and their contents include but are not limited to the structural parameters of the wheel-rail system, the wheel-rail contact geometric parameters and the mechanical properties of the wheel-rail material. The determination of these three parameters is directly related to the accuracy of the model and the reliability of the subsequent static solution. Therefore, in practical applications, they need to be obtained and verified one by one in combination with engineering standards, measured data or authoritative design parameter manuals.

[0031] The structural parameters of the wheel-rail system define the geometric dimensions and relative position of the wheelset and track, the spatial relationship between the wheel tread and rail surface, and physical dimensions such as the wheelset wheelbase, wheel diameter, and track gauge. These parameters should be based on high-speed railway design standards or actual line measurement data and must not be arbitrarily assumed or simplified to prevent distortion of subsequent dynamic solution results. Wheel-rail contact geometric parameters primarily describe the contact geometry between the wheelset tread and the rail top surface, the initial distribution of contact points, the contact angle, and the relative positional accuracy between the wheel and rail. Determination of these parameters is crucial for accurately describing the mechanical behavior of wheel-rail contact. They should be derived from characteristic data such as the wheelset tread type (e.g., S1002) and rail type (e.g., 60E1 or 60kg / m rail) combined with geometric data or analytical wheel-rail contact calculations. The mechanical properties of the wheel-rail material include fundamental mechanical parameters such as density, elastic modulus, and Poisson's ratio of the wheelset and track components, which describe the static and dynamic response characteristics of the material. Material parameters should preferably adopt measured data of typical materials in high-speed railway projects (such as railway wheel steel and U71Mn rails) or values ​​given by authoritative standards.

[0032] After completing the preparation of the above-mentioned basic parameters of the high-speed railway wheel and rail, the high-speed wheel and rail finite element model is constructed based on the said parameters. Specifically, first, the wheel group power unit model and the track bearing unit model are respectively established based on the structural parameters of the wheel and rail system. The wheel group power unit model is used to describe the dynamic parameters of the wheel group, such as the geometric dimensions, mass distribution, and rotational inertia. Its finite element division should ensure that the mesh division of key contact parts such as the wheel tread and wheel flange is fine and the physical properties are complete. The node setting of the wheel group power unit should meet the definition requirements of the rotational degree of freedom, so as to facilitate the application of torque or rotational inertia state in the subsequent dynamic solution. The track bearing unit model is used to describe the spatial layout, support conditions and dynamic response characteristics of the track structure. The model should include sub-structural units such as rails, simplified support of the roadbed, and fastener stiffness. Its mesh division should take into account both accuracy and computational efficiency. The mesh density of key stress-bearing parts such as the rail head and rail waist can be appropriately increased.

[0033] After establishing the wheelset power unit model and the track bearing unit model, a wheel-rail contact unit model is constructed based on these two models to determine the contact dynamic parameters between the wheelset and the track. The wheel-rail contact unit model must define the wheel-rail contact pair, contact stiffness, friction coefficient, contact tracking algorithm, and other contents, and achieve precise coupling of the wheel-rail contact relationship in spatial geometry to ensure that data such as contact force, contact area, and contact pressure can be output in real time during subsequent solutions. Based on the wheelset power unit model, the track bearing unit model, and the wheel-rail contact unit model, the three are coupled to finally complete the overall establishment of the high-speed wheel-rail finite element model. In actual engineering applications, this model file can usually be exported to mainstream finite element solvers (such as ABAQUS, ANSYS, etc.) for direct call-up for static loading or dynamic simulation.

[0034] After the high-speed wheel-rail finite element model is constructed, static loading is performed on it to obtain a finite element model in a static state. The specific steps of static loading include: applying a vertical gravity load corresponding to the wheelset and sprung mass to the wheelset power unit model to simulate the effect of the wheelset's own weight on the track in a static state; applying support boundary constraints to the track bearing unit model to simulate the track's boundary conditions such as fastener stiffness, roadbed support or bridge foundation under actual working conditions. The above-mentioned gravity load application and boundary constraint application must simultaneously meet physical rationality and numerical stability, that is, the gravity load size must be equivalent to the actual vehicle's own weight, and the support boundary stiffness must reasonably reflect the actual working conditions of the roadbed and foundation.

[0035] Based on the results of vertical gravity load application and support constraint application, a static equilibrium solution is performed on the high-speed wheel-rail finite element model. Specifically, based on the results of vertical gravity load application, the initial static load effect of the wheel group power unit model in a static state is generated, including the force distribution of the wheel group nodes, the initial normal force and friction force at the wheel-rail contact point, etc. Based on the results of support constraint application, the degree of freedom of the boundary nodes of the track bearing unit model is limited to prevent the track model from generating rigid body displacement or non-physical deformation during the static solution process. Based on the above initial conditions, a static equilibrium solution is performed on the high-speed wheel-rail finite element model, that is, the equilibrium state of each node of the model under the action of static load is obtained through finite element static iterative calculation.

[0036] During the solution process, physical data such as the static displacement, static stress, contact force, contact area, and contact stiffness of each node can be recorded. The static displacement data is used to express the overall deformation state of the model under the action of gravity and support, the static stress data is used to express the internal stress distribution of components such as the track and wheelset, and the wheel-rail contact parameters are used to characterize the local mechanical state of the wheel-rail contact area. Based on the above data, the finite element model in the static state is determined. This model can be used as the physical initial condition for subsequent dynamic working condition loading, explicit acceleration solution, and transient dynamic solution, ensuring that the dynamic simulation starts from the real physical equilibrium state and improving the simulation accuracy and convergence.

[0037] The high-speed wheel-rail finite element model constructed by the present invention using the above-mentioned rules can truly reflect the static physical state of the high-speed wheel-rail system. The static loading process conforms to physical laws and engineering practice, and does not introduce simulation errors or numerical convergence problems due to inconsistent initial conditions. At the same time, the complete record of the wheel-rail contact relationship, support conditions, and node status can provide a high-precision physical foundation for the subsequent dynamic loading and smooth acceleration stages, effectively improving the stability and reliability of the entire simulation chain. This solution can meet the requirements for modeling accuracy, physical consistency, and numerical stability in high-speed wheel-rail system engineering simulation, providing effective support for engineering applications and scientific research analysis.

[0038] Step S20: performing dynamic working condition loading on the finite element model in the static state to obtain a finite element model with a rotational inertia state.

[0039] Specifically, based on the finite element model in a stationary state, a traction torque is applied to the axle rotational freedom of the wheelset power unit model, and the wheelset rotational inertia is gradually introduced through implicit static solution, forming a natural loading process model in which the centrifugal force and wheel-rail contact force develop with the rotational speed; based on the natural loading process model, the wheel-rail contact parameters and the node stress state are recorded in real time during the torque loading process, and after the wheelset rotational inertia state converges, a finite element model with a rotational inertia state is obtained based on the wheel-rail contact parameters and the node stress state at the corresponding moment.

[0040] In an embodiment of the present invention, dynamic working condition loading is performed on the finite element model in the static state to obtain a finite element model with a rotational inertia state. Clear loading steps and solution rules should be followed to ensure the physical consistency and numerical stability of the dynamic loading process. Specifically, on the basis of completing the static working condition loading and obtaining the finite element model in the static state, a traction torque is applied to the axle rotational freedom degree of the wheelset power unit model to gradually introduce the rotational inertia state of the wheelset. The application of traction torque needs to be based on the target torque value of the preset working condition, and loaded in a staged incremental manner to avoid the introduction of initial disturbances or numerical oscillations in the simulation due to a sudden increase in torque. During the loading process, it is recommended to adopt an implicit static solution strategy to gradually solve the rotational response of the wheelset under the action of torque to ensure that each step of the solution converges to a physical equilibrium state.

[0041] During the traction torque loading process, as the wheelset's rotational inertia gradually builds up, the wheel-rail contact state and centrifugal force field evolve accordingly. To ensure the controllability and physical authenticity of the loading process, the wheel-rail contact parameters should be recorded in real time, including the normal force, tangential force, contact stiffness, and contact area at the wheel-rail contact point, as well as the stress tensor distribution at each key node. These data are used to dynamically monitor the loading process and assist in determining the convergence of the rotational inertia state. The convergence of the wheelset's rotational inertia state can be determined based on whether the rate of change of the wheel-rail contact parameters and the amplitude of the change in the node stress state are below a preset threshold. When the amplitude of the change in the relevant parameters in multiple consecutive loading steps is below the threshold, it can be considered that convergence to a stable rotational inertia state has occurred.

[0042] After the wheelset's rotational inertia state reaches convergence, a finite element model with a rotational inertia state can be determined based on the wheel-rail contact parameters and nodal stress states recorded at that moment. This model contains complete information on wheel-rail rotational inertia, centrifugal force fields, wheel-rail contact forces, and internal stress states, and can serve as a high-precision physical initial condition for subsequent explicit acceleration loading or transient dynamic solutions of target operating conditions. This dynamic operating condition loading process enables a natural transition of physical processes, avoids simulation perturbations caused by sudden changes in initial conditions, ensures the numerical stability and physical consistency of subsequent dynamic simulations, and meets the accuracy requirements of engineering simulations under high-speed wheel-rail operating conditions.

[0043] Step S30: performing explicit acceleration loading on the finite element model in the rotational inertia state, and obtaining a finite element model in a steady state after reaching a target speed.

[0044] Specifically, based on the finite element model in the rotational inertia state, the rotation speed of the wheelset power unit model is gradually increased by an explicit solution algorithm until the preset target speed is reached; during the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are dynamically adjusted; after the wheelset power unit model reaches the target speed and the wheel-rail dynamic response parameters meet the preset standards, the finite element model in the current state is used as the finite element model in the steady state.

[0045] Furthermore, during the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are dynamically adjusted, including: based on the wheel-rail dynamic response parameters, the wheelset displacement time history, wheel-rail contact force time history, node stress change, hourglass energy change and internal energy change of the wheelset power unit model are obtained in real time to determine the disturbance level of the acceleration process; when the disturbance level exceeds a preset threshold, the simulation step size, damping coefficient and / or acceleration rate in the acceleration control parameters are adjusted, and the disturbance level of the acceleration process is re-determined after the adjustment until the disturbance level of the acceleration process is lower than the preset disturbance threshold, and it is determined that the wheel-rail dynamic response parameters meet the preset standard.

[0046] In an embodiment of the present invention, explicit acceleration loading is performed on the finite element model with a rotational inertia state. After reaching the target speed, a finite element model in a stable state is obtained. This requires adherence to rigorous loading procedures and solution rules to ensure physical smoothness and numerical convergence throughout the acceleration process, avoiding simulation perturbations or energy imbalances introduced by improper loading methods. Specifically, based on the established finite element model with a rotational inertia state, an explicit solution algorithm is used to gradually increase the rotational speed of the axle rotational degrees of freedom of the wheelset power unit model. A phased incremental loading strategy is recommended for this increase. Specifically, during the explicit acceleration phase, the target speed range is divided into several sub-stages. The speed increment and loading time step for each sub-stage should be appropriately set based on pre-set physical conditions and the solver's convergence requirements. This approach allows for the physical simulation of the wheelset's smooth transition from an initial rotational inertia state to a high-speed operating state, avoiding the introduction of non-physical perturbations due to instantaneous speed jumps.

[0047] During explicit acceleration loading, the wheel-rail dynamic response parameters must be monitored in real time to ensure the smoothness of the acceleration process and the physical consistency of the simulation. The wheel-rail dynamic response parameters include at least the wheelset displacement time history of the wheelset power unit model, the wheel-rail contact force time history, the stress changes at each node, the hourglass energy changes, and the internal energy changes. These parameters are used to dynamically determine the disturbance level during the acceleration loading process, focusing on whether unreasonable loading strategies or insufficient numerical stability lead to sudden changes in local node stress, abnormal fluctuations in contact forces, or energy non-conservation during the acceleration process. After each loading step, the rate of change of the disturbance level should be calculated based on the above wheel-rail dynamic response parameters. If the rate of change exceeds the preset disturbance threshold, the dynamic adjustment mechanism of the acceleration control parameters should be immediately triggered.

[0048] The dynamic adjustment of acceleration control parameters specifically includes adjusting the simulation step size, damping coefficient and / or acceleration rate to timely suppress disturbances and restore the numerical convergence of the solution. The simulation step size is generally adjusted by a step-by-step reduction strategy to improve the time resolution and accuracy of the solution; the damping coefficient can be adjusted adaptively according to the disturbance change trend to quickly eliminate local high-frequency numerical oscillations; the acceleration rate should be adjusted in combination with the rationality of physical loading and the stability of simulation to ensure that the acceleration loading is both efficient and stable. After each round of parameter adjustment, the wheel-rail dynamic response parameters should be re-monitored, the adjusted disturbance level change rate should be calculated, and compared with the preset disturbance threshold. Repeat this monitoring and adjustment process until the disturbance level is stably lower than the preset disturbance threshold.

[0049] When the wheelset power unit model reaches the preset target speed during explicit acceleration loading and the wheel-rail dynamic response parameters meet preset standards, the current finite element model state can be considered a steady-state finite element model. At this point, the wheelset's rotational inertia, centrifugal force field, wheel-rail contact state, and internal stress distribution in the model have all reached a physically stable state, and the fluctuation range of various dynamic response parameters remains within an acceptable range. This steady-state finite element model can be used as the initial condition for subsequent transient dynamic solutions for target operating conditions, supporting dynamic simulation analysis of high-speed wheel-rail operating conditions.

[0050] Through the above-mentioned explicit acceleration loading process, the physical process of the wheelset gradually increasing from a state of rotational inertia to a high-speed operating state can be realistically reproduced in numerical calculations, and real-time monitoring and feedback control of disturbances can be achieved during the loading process. This loading method effectively avoids problems such as sudden contact force changes, node stress jumps, and energy imbalances that may be caused by directly applying the target speed or instantaneous acceleration, significantly improving the numerical stability and physical consistency of the simulation. The finite element model finally obtained in the steady state can provide high-precision, physically reasonable initial input conditions for solving the target working condition dynamics, and provide reliable data support for engineering simulation and safety assessment of high-speed wheel-rail systems.

[0051] Step S40: Based on the finite element model in the steady state, a transient dynamic solution is performed on the target working condition to be simulated, and a wheel-rail dynamic response parameter set of the target working condition is output.

[0052] Specifically, a physical parameter set of the current target working condition to be simulated is obtained; the wheel-rail initial physical state parameter set of the finite element model in a steady state is loaded based on the physical parameter set to construct a finite element initial state matching the current target working condition; a transient dynamic solution is performed based on the finite element initial state, and a wheel-rail dynamic response parameter set is output in real time to describe the wheel-rail dynamic behavior and energy balance state under the current target working condition.

[0053] Specifically, the physical parameter set of the target working condition to be simulated currently includes: target speed, target track segment geometry, wheel-rail contact initial conditions and external working condition boundary information.

[0054] In this embodiment of the present invention, a transient dynamic solution is performed for the target operating condition to be simulated based on a finite element model in a steady state, outputting a set of wheel-rail dynamic response parameters for the target operating condition. This operation must strictly adhere to physical parameter loading and solution rules to ensure the physical consistency and engineering usability of the solution results. First, the physical parameter set for the target operating condition to be simulated should be obtained. This physical parameter set should at least include the target speed, target track segment geometry, initial wheel-rail contact conditions, and external operating condition boundary information. The target speed should be determined based on engineering design or test conditions, such as the actual operating speed or design speed of a high-speed line. The target track segment geometry characterizes the spatial shape of the track under the target operating condition and includes geometric information such as the track plane, longitudinal section, gauge variation, curve radius, and superelevation. These parameters can be obtained from line design drawings or measured data. The initial wheel-rail contact conditions primarily include parameters such as the initial contact position, contact angle, and initial normal force between the wheelset tread and the track surface. The accuracy of this data is directly related to the accuracy of the contact mechanics solution. External working condition boundary information generally refers to external environmental loading conditions, such as wind load, temperature field, and additional vibration input from bridges, which are used to define the boundary environment of the wheel-rail system under the target working condition.

[0055] After the above-mentioned physical parameter set is obtained, the wheel-rail initial physical state parameter set of the finite element model in the steady state should be loaded based on the physical parameter set. The wheel-rail initial physical state parameter set here contains data such as the initial static or steady-state displacement of each node in the model, the initial stress state of the node, the wheel-rail contact parameters, the wheelset rotational inertia state, etc., which is used to numerically restore the physical field distribution of the finite element model in the steady state. During the loading process, it is necessary to accurately couple the physical parameters of the target working condition with the finite element model parameters in the steady state. For example, the target speed needs to be adjusted accordingly to the wheelset rotation state, and the track geometry state changes require updating the node coordinates and boundary constraints of the track bearing unit. The initial wheel-rail contact conditions need to be consistent with the wheel-rail contact parameter set in the steady state or be appropriately modified based on the target working condition.

[0056] After the initial finite element state is constructed, a transient dynamic solution is performed based on this state, and the wheel-rail dynamic response parameter set is output in real time during the solution process. The wheel-rail dynamic response parameter set includes the wheelset displacement time history, wheel-rail contact force time history, node stress changes, hourglass energy changes, and internal energy changes. It is used to fully record the wheel-rail dynamic behavior, contact mechanical response, and energy balance state under the target working conditions. The real-time output of this data can not only be used for simulation convergence monitoring, but also provide basic data support for engineering safety assessment, vibration control, contact fatigue analysis, etc. Through the above-mentioned solution rules, the accuracy and engineering usability of the wheel-rail dynamic response under the target working conditions can be ensured physically and numerically, avoiding simulation errors or numerical non-convergence problems caused by inconsistent initial conditions or incomplete loading of physical parameters.

[0057] In one possible implementation, consistent with traditional methods, a gravity field is applied to the entire model; in implicit static analysis, traction torque is applied to the wheel axle. To avoid centrifugal force disturbances, a wheel acceleration step is implemented before high-speed wheel rolling, allowing acceleration to be achieved within the explicit dynamic step. The obtained steady-state results, including the wheel rotational and translational velocities, are input into the transient model as initial conditions for the analysis, yielding a transient explicit solution. This improved model addresses two key challenges: first, eliminating the need for a dynamic relaxation zone and avoiding initial transient responses. Second, it accelerates computational convergence, improving computational efficiency.

[0058] For example, the traditional method and the improved method are used to perform high-speed simulation at a speed of 350 km / h to calculate the vertical wheel-rail force and the lateral wheel-rail force, focusing on observing the initial disturbance. The calculation results of the vertical wheel-rail force and the lateral wheel-rail force are as follows: Figure 2 and Figure 3As shown. According to the wheel-rail force calculation results, the vertical wheel-rail force calculated by the traditional method has a large initial turbulence, which is mainly due to the instantaneous impact of the wheel centrifugal force. Due to the damping effect, the turbulence gradually decreases with the increase of the running distance. Finally, the fluctuation amplitude of the vertical wheel-rail force is 5.76kN, which is about 5.76% of the static wheel load. The initial turbulence of the improved method is very small, with only a maximum fluctuation of 3.02kN in the early stage of the solution area, and the fluctuation in the later stage is basically negligible. The characteristics of the lateral wheel-rail force are similar to those of the vertical wheel-rail force. The traditional method still has a large initial turbulence, and the fluctuation amplitude is larger than that of the improved method.

[0059] Furthermore, in the calculation of the three-dimensional high-speed wheel-rail rolling contact finite element model, how to reduce the time consumption is one of the difficult problems in solving the problem. In the implicit calculation, the Newton-Raphson iterative method is used for solution. In order to make the model converge, it is necessary to set a reasonable load sub-step. Compared with the implicit calculation, the explicit dynamic solution stage is the main time-consuming step. After considering the wheel rotation inertia, it is necessary to add a load step, but the load sub-step can be reduced, so it has almost no effect on the implicit solution time. If you want to achieve the same result as the improved method through the traditional method, you can add a transition zone or solution zone. In this way, the number of meshes in the finite element model will increase significantly, which will greatly reduce its computational efficiency at the expense of simulation time. In addition, due to the existence of the dynamic relaxation zone, the number of meshes in the traditional method is more than that of the improved method, which will also increase its computational cost and reduce computational efficiency.

[0060] Figure 4 This is a system structure diagram of a three-dimensional transient wheel-rail contact simulation system in an accelerated state provided by an embodiment of the present invention. Figure 4 As shown, an embodiment of the present invention provides a three-dimensional transient wheel-rail contact simulation system in an accelerated state, the system comprising: a model construction unit for constructing a high-speed wheel-rail finite element model based on basic parameters of the high-speed railway wheel and rail, and performing static working condition loading on the high-speed wheel-rail finite element model to obtain a finite element model in a stationary state; a dynamic loading unit for performing dynamic working condition loading on the finite element model in the stationary state to obtain a finite element model with a rotational inertia state; an acceleration state simulation unit for performing explicit acceleration loading on the finite element model with a rotational inertia state to obtain a finite element model in a steady state after reaching a target speed; and an output unit for performing transient dynamic solution for the target working condition to be simulated based on the finite element model in the steady state, and outputting a wheel-rail dynamic response parameter set of the target working condition.

[0061] Those skilled in the art will appreciate that all or part of the steps in the methods of the aforementioned embodiments can be accomplished by instructing the relevant hardware through a program. The program is stored in a storage medium and includes a number of instructions for causing a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0062] The above describes in detail the optional embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, a variety of simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the scope of protection of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is any contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will no longer describe the various possible combinations separately.

[0063] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A three-dimensional transient wheel-rail contact simulation method in an accelerated state, characterized in that: The method comprises: A high-speed wheel-rail finite element model is constructed based on the basic parameters of the high-speed railway wheel and rail, and static loading is performed on the high-speed wheel-rail finite element model to obtain a finite element model in a static state; Performing dynamic working condition loading on the finite element model in the static state to obtain a finite element model with a rotational inertia state, comprising: Based on the finite element model in a static state, a traction torque is applied to the axle rotational freedom of the wheelset power unit model. The wheelset rotational inertia is gradually introduced through implicit static solution, forming a natural loading process model in which the centrifugal force and wheel-rail contact force develop with the rotational speed. Based on the natural loading process model, the wheel-rail contact parameters and the nodal stress state are recorded in real time during the torque loading process, and after the wheelset rotational inertia state converges, a finite element model with a rotational inertia state is obtained based on the wheel-rail contact parameters and the nodal stress state at the corresponding moment; Performing explicit acceleration loading on the finite element model in a rotational inertia state, and obtaining a finite element model in a steady state after reaching a target speed; Based on the finite element model in the steady state, a transient dynamic solution is performed for the target working condition to be simulated, and the wheel-rail dynamic response parameter set of the target working condition is output.

2. The three-dimensional transient wheel-rail contact simulation method in an accelerated state according to claim 1, characterized in that: The basic parameters of high-speed railway wheels and rails include: Structural parameters of the wheel-rail system, wheel-rail contact geometry parameters, and mechanical properties of wheel-rail materials; The high-speed railway wheel-rail finite element model is constructed based on the basic parameters of the high-speed railway wheel-rail, including: Based on the structural parameters of the wheel-rail system, the wheel group power unit model and the track bearing unit model are established respectively; The wheel group power unit model is used to describe the wheel group dynamic parameters; The track bearing unit model is used to describe the dynamic parameters of the track; A wheel-rail contact unit model is constructed based on the wheelset power unit model and the track bearing unit model to determine the contact dynamic parameters between the wheelset and the track; The high-speed wheel-rail finite element model is obtained based on the coupling of the wheelset power unit model, the track bearing unit model and the wheel-rail contact unit model.

3. The three-dimensional transient wheel-rail contact simulation method in acceleration state according to claim 2, characterized in that: Perform static loading on the high-speed wheel-rail finite element model to obtain a finite element model in a static state, including: Apply a vertical gravity load corresponding to the wheelset and sprung mass to the wheelset power unit model; Apply support boundary constraints to the track bearing unit model; Based on the results of vertical gravity load application and support constraint application, the static equilibrium solution is performed on the high-speed wheel-rail finite element model to obtain the finite element model in the static state.

4. The three-dimensional transient wheel-rail contact simulation method in an accelerated state according to claim 3, characterized in that: Based on the results of vertical gravity load application and support constraint application, a static equilibrium solution is performed on the high-speed wheel-rail finite element model to obtain a finite element model in a static state, including: Generate the initial static load of the wheel power unit model in a stationary state based on the vertical gravity load application results; Based on the support constraint application results, the degree of freedom of the boundary nodes of the track bearing unit model is limited; Based on the initial static load and the degrees of freedom of the boundary nodes of the track bearing unit model, the high-speed wheel-rail finite element model is subjected to static equilibrium solution to obtain the static displacement, static stress and wheel-rail contact parameters of each node. The finite element model in the static state is obtained based on the static displacement, static stress and wheel-rail contact parameters of each node.

5. The three-dimensional transient wheel-rail contact simulation method in acceleration state according to claim 1, characterized in that: Performing explicit acceleration loading on the finite element model in a rotational inertia state to obtain a finite element model in a steady state after reaching a target speed, comprising: Based on the finite element model under the state of rotational inertia, the rotation speed of the wheel set power unit model is gradually increased by an explicit solution algorithm until the preset target speed is reached; During the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are adjusted dynamically; After the wheelset power unit model reaches the target speed and the wheel-rail dynamic response parameters reach the preset standards, the finite element model in the current state is used as the finite element model in the steady state.

6. The three-dimensional transient wheel-rail contact simulation method in acceleration state according to claim 5, characterized in that: During the acceleration process, the wheel-rail dynamic response parameters are monitored in real time, and the acceleration control parameters are dynamically adjusted, including: Based on the wheel-rail dynamic response parameters, the wheelset displacement time history, wheel-rail contact force time history, node stress change, hourglass energy change and internal energy change of the wheelset power unit model are obtained in real time to determine the disturbance level of the acceleration process; When the disturbance level exceeds a preset threshold, the simulation step size, damping coefficient and / or acceleration rate in the acceleration control parameters are adjusted, and the acceleration process disturbance level is re-determined after the adjustment until the acceleration process disturbance level is lower than the preset disturbance threshold, and it is determined that the wheel-rail dynamic response parameters meet the preset standards.

7. The three-dimensional transient wheel-rail contact simulation method in acceleration state according to claim 1, characterized in that: Based on the finite element model in the steady state, a transient dynamic solution is performed for the target working condition to be simulated, and the wheel-rail dynamic response parameter set of the target working condition is output, including: Obtain the physical parameter set of the target working condition to be simulated; Based on the initial physical state parameter set of the wheel / rail of the finite element model in the steady state loaded by the physical parameter set, the finite element initial state matching the current target working condition is constructed; A transient dynamic solution is performed based on the finite element initial state, and a wheel-rail dynamic response parameter set is output in real time to describe the wheel-rail dynamic behavior and energy balance state under the current target working condition.

8. The three-dimensional transient wheel-rail contact simulation method in acceleration state according to claim 7, characterized in that: The physical parameter set of the target working condition to be simulated currently includes: Target speed, target track segment geometry, initial wheel-rail contact conditions and external working condition boundary information.

9. A three-dimensional transient wheel-rail contact simulation system in an accelerated state, characterized in that: The system comprises: A model building unit is used to build a high-speed wheel-rail finite element model based on the basic parameters of the high-speed railway wheel and rail, and perform static working condition loading on the high-speed wheel-rail finite element model to obtain a finite element model in a static state; A dynamic loading unit, configured to perform dynamic working condition loading on the finite element model in the static state to obtain a finite element model with a rotational inertia state, comprising: Based on the finite element model in a static state, a traction torque is applied to the axle rotational freedom of the wheelset power unit model. The wheelset rotational inertia is gradually introduced through implicit static solution, forming a natural loading process model in which the centrifugal force and wheel-rail contact force develop with the rotational speed. Based on the natural loading process model, the wheel-rail contact parameters and the nodal stress state are recorded in real time during the torque loading process, and after the wheelset rotational inertia state converges, a finite element model with a rotational inertia state is obtained based on the wheel-rail contact parameters and the nodal stress state at the corresponding moment; an acceleration state simulation unit, configured to perform explicit acceleration loading on the finite element model in a rotational inertia state, and obtain a finite element model in a steady state after reaching a target speed; The output unit is used to perform transient dynamic solution for the target working condition to be simulated based on the finite element model in the steady state, and output the wheel-rail dynamic response parameter set of the target working condition.

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