Method for calculating rubber load and wheel rail acting force of compression shear type elastic wheel of railway vehicle

Abstract

The invention relates to the technical field of railway vehicles, in particular to a railway vehicle compression shear type elastic wheel rubber load and wheel rail acting force calculation method, which comprises the following steps: S1, mounting a displacement sensor and an acceleration sensor on a wheel, the sensor is used for collecting relative displacement between a wheel rim and a wheel center and vibration acceleration of the wheel rim; s2, carrying out a vertical loading test and a transverse loading test on the elastic wheel by adopting a bench test or finite element simulation method, and calculating the vertical rigidity, the transverse rigidity and the torsional rigidity of the wheel rubber device; s3, carrying out a line test on the vehicle, collecting displacement and vibration data of wheels, and calculating vertical acceleration and transverse acceleration of a wheel rim; and S4, calculating the loading force, the wheel rail vertical force and the wheel rail transverse force of the wheel rubber device. The method is used for solving the technical problems that a traditional force measurement wheel pair is not suitable for wheel rail force detection of the compression shear type elastic wheel and cannot provide key parameters for evaluating the running safety of a train.

Description

Technical Field

[0001] The present invention relates to the technical field of rail vehicles, and in particular to a calculation method for rubber loads and wheel-rail interaction forces of a compression-shear type elastic wheel of a rail vehicle. Background Art

[0002] The descriptions in this section only provide background information related to the present disclosure and do not constitute prior art.

[0003] Rail transit systems are mainly divided into several categories: steel wheel-rail systems (subway systems, suburban rapid rail systems, ordinary railways, high-speed railways, tramways, etc.), maglev transportation systems (medium and low-speed maglev systems, high-speed maglev systems, vacuum tube maglev systems), monorail systems (suspended monorails, straddle monorails), rubber tire-guide rail systems (rubber tire guide rail trams, cloud rails, etc.), and rubber tire electronic guidance systems (rubber tire vehicles operating on a pre-determined road track line). Currently, worldwide, the vast majority of transportation systems use steel wheel-rail systems, and the vast majority of rail transit systems under construction still use steel wheel-rail systems.

[0004] Currently, in rail transit systems using steel wheels and rails, the running gear of vehicles mainly uses integral wheelsets, and the railway subgrade is mostly of concrete structure. Due to the high rigidity of the wheel and track systems, the wear and running noise of the wheels and rails are relatively large. As the service time increases, subgrade settlement and wheel-rail wear will further deteriorate the vehicle and track systems, resulting in poor riding comfort for passengers. Currently, the problems of wheel-rail wear and noise in the subway systems of many large cities in China are very prominent, seriously affecting the living environment of the surrounding residents. From the perspective of the dynamics of the rail vehicle system, reducing the contact force between the wheels and rails can effectively reduce wheel-rail noise and the vibration of the vehicle-track system, and improve the running comfort. Currently, using elastic wheels is one of the effective technical means to reduce wheel-rail forces and wheel-rail noise.

[0005] The advantages of elastic wheels include: First, they can effectively reduce the wheel-rail force. The unsprung mass of the elastic wheel is only the wheel tyre, and the wheel tyre mass is much smaller than the mass of the traditional rigid wheel. According to the vehicle-track coupling dynamics theory, the wheel-rail vibration impact force is proportional to the unsprung mass. Elastic wheels can effectively reduce the dynamic wheel-rail force. Second, they can effectively reduce wheel-rail noise. The rubber element between the wheel tyre and the wheel center of the elastic wheel can absorb high-frequency vibrations, thereby reducing the dynamic wheel-rail force and wheel noise. The rubber element can block the transmission of wheel-rail rolling contact noise to the vehicle body, thereby effectively reducing the noise inside the vehicle and improving ride comfort. Tests conducted by the railway transportation departments of the United States, Europe and Japan show that compared with trains using traditional rigid wheels, the dynamic wheel-rail force of trains using elastic wheels is reduced by 30% to 40%, the noise inside the vehicle is reduced by 3dB (A), and the curve passing noise is reduced by 10 to 20dB (A). Third, elastic wheels can effectively reduce wheel-rail wear. Due to the reduction of the dynamic force between the wheel and the rail, the normal contact force and creep force of the wheel-rail contact surface are reduced, and the wear of the wheel-rail contact surface (tread and wheel flange) is reduced, and the wheel turning and repair cycle and the service life of the wheel-rail system are extended. Domestic and foreign engineering experience shows that after the use of elastic wheels, the life of wheels and lines is increased by 20% to 40%. At present, compared with traditional rigid wheels, the disadvantages of elastic wheels are complex structure, high cost, difficulty in installation and maintenance, and unsuitability for rail vehicles with axle weight greater than 15 tons. In addition, the fatigue life of the wheel tyre must be guaranteed to ensure the safety of the elastic wheel.

[0006] Elastic wheel structures can be divided into three categories: compression type, shear type, and compression shear type. The radial stiffness and lateral stiffness of compression wheels are poorly matched and are rarely used. Shear type wheels mainly bear radial force and tangential force, but they have complex structures, high costs, and are inconvenient to install and disassemble. They are currently only used in the United States and Hong Kong, China. The rubber elements of compression shear type wheels can produce compression and shear deformation at the same time, have a simple structure, and are easy to maintain, which is the future development direction.

[0007] The detection of wheel-rail forces is one of the important contents of vehicle dynamics testing. The derailment coefficient and wheel load reduction rate calculated based on wheel-rail forces are the most important indicators for evaluating the running safety of trains. For traditional rail vehicles equipped with rigid wheels, the commonly used measuring device is a force-measuring axle. By pasting a number of strain gauges on the spoke surface of the rigid wheel according to a certain arrangement to form a Wheatstone measuring bridge, the intermittent or continuous measurement of wheel-rail forces is realized. However, for rail vehicles equipped with elastic wheels, due to the isolation of the rubber device, the strain on the spoke surface of the wheel cannot reflect the contact force between the wheel tyre and the rail. That is to say, the traditional measuring method of the force-measuring axle is not applicable to the detection of wheel-rail forces of elastic wheels. The invention contents of the relevant patents on elastic wheels in the prior art include the structural design of elastic wheels, manufacturing methods and processes, the structural design of press-fitting devices, and assembly and disassembly processes, but no patents identical or similar to the present invention have been found. Therefore, to solve this problem, the present invention proposes a new method for detecting and calculating wheel-rail forces of elastic wheels, which is mainly applicable to rail vehicles using compression-shear type elastic wheels. Summary of the Invention

[0008] The object of the present invention is to provide a calculation method for the rubber load and wheel-rail forces of a compression-shear type elastic wheel of a rail vehicle, which is used to solve the technical problems that the traditional force-measuring axle is not applicable to the detection of wheel-rail forces of compression-shear type elastic wheels and cannot provide key parameters for evaluating the running safety of trains.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A calculation method for the rubber load and wheel-rail forces of a compression-shear type elastic wheel of a rail vehicle, the method comprising the following steps:

[0011] S1. Install displacement sensors and acceleration sensors on the wheel to collect the relative displacement between the wheel tyre and the wheel center and the vibration acceleration of the wheel tyre;

[0012] S2. Adopt bench test or finite element simulation method to conduct vertical loading test and lateral loading test on the elastic wheel, and calculate the vertical stiffness, lateral stiffness and torsional stiffness of the wheel rubber device by using the data collected in step S1;

[0013] S3. Conduct a line test on the vehicle, collect the displacement and vibration data of the wheel, and calculate the vertical acceleration and lateral acceleration of the wheel tyre;

[0014] S4. Calculate the load force of the wheel rubber device, the vertical wheel-rail force and the lateral wheel-rail force.

[0015] Furthermore, in step S1, the displacement sensor includes four lateral displacement sensors circumferentially arranged and installed on the outside or inside of the wheel rim and four radial displacement sensors circumferentially arranged and installed on the outside or inside of the wheel rim, and the acceleration sensor adopts four two-way vibration acceleration sensors circumferentially arranged and installed on the inside or outside of the wheel rim, wherein the angle between adjacent radial displacement sensors is 90° and the direction of measuring displacement is radial, the angle between adjacent lateral displacement sensors is 90° and the direction of measuring displacement is lateral, and the angle between adjacent acceleration sensors is 90° and the measuring direction includes radial and axial directions parallel to the axle axis.

[0016] Furthermore, in step S2, a vertical load and a lateral load are applied to the wheel, a radial displacement change is obtained through a radial displacement sensor, and the vertical stiffness of the wheel rubber device is calculated based on the vertical load and the radial displacement change, a lateral displacement change is obtained through a lateral displacement sensor, and the lateral stiffness and torsional stiffness of the wheel rubber device are calculated based on the lateral load and the lateral displacement change.

[0017] Furthermore, in step S2, the specific method for calculating the vertical stiffness of the wheel rubber device is:

[0018] S211, according to the change of the position coordinates of two adjacent sensors before and after vertical loading, the displacement Δr of the i-th radial displacement sensor is obtained respectively. i and the jth radial displacement sensor displacement Δr j The mathematical expression of the wheel rim is obtained by combining these two mathematical expressions to obtain the function f(Δz i ), and list the function f(Δz i ). Finally, the Newton iteration method is used to obtain the vertical displacement Δz of the wheel rim. i Approximate numerical solution, and then the four Δz i The final wheel rim vertical displacement Δz is obtained by taking the average value.

[0019] S212. Calculate the vertical stiffness of the wheel rubber device: Substitute the vertical load F V Starting from 10 kN, the load is gradually increased to 1.5 times of the static wheel weight at intervals of 10 kN. After each loading, the vertical displacement Δz is calculated using the method shown in step S211, and then F V The vertical stiffness K is obtained by linear interpolation of the vertical displacement Δz wz .

[0020] Furthermore, in step S2, the specific method for calculating the lateral stiffness and torsional stiffness of the wheel rubber device is:

[0021] S221. Collect the displacement data Δy1, Δy2, Δy3, Δy4 of the initial states of four lateral displacement sensors, as well as the displacement data Δy1′, Δy2′, Δy3′, Δy4′ after applying the lateral load, and calculate the lateral relative displacement of the four detection points;

[0022] S222. Set the lateral displacement of the wheel tyre under the lateral load as a harmonic function. The mathematical expressions of the lateral displacements of two sensors spaced 90 degrees apart respectively include sine and cosine terms. Then, according to the principle that the sum of the squares of sine and cosine is 1, obtain the lateral displacement equations of two adjacent sensors. Use the conventional quadratic formula for finding roots to solve the displacement equations to obtain the lateral displacement dy0 caused by the pure lateral force. Substitute dy0 into the lateral displacement equation to obtain the maximum lateral displacement dy of the wheel tyre max and the maximum lateral displacement caused by the pure bending moment is (dy max -dy0);

[0023] S223. Calculate the lateral stiffness and the roll-torsion stiffness of the rubber device:

[0024] S2231. Start with the lateral load F H from 10 kN and increase it step by step at intervals of 10 kN to 1.2 times the static wheel weight. After each load application, use the method shown in step S222 to calculate the vertical displacement dy0, dy max , (dy max -dy0) once. Then, perform linear interpolation on the lateral load F H and the lateral relative displacement dy0 to obtain the lateral stiffness K wy of the rubber device;

[0025] S2232. Assume the position radius of the lateral displacement sensor on the wheel tyre is R yr , and the angle of torsional deformation is equal to the maximum lateral displacement caused by the bending moment divided by the installation position radius of the lateral displacement sensor on the wheel tyre;

[0026] S2233. Perform linear interpolation on the additional bending moment M H of the lateral force and the angle of torsional deformation to obtain the torsional stiffness where M H =F H ×r0, F H refers to the lateral load, and r0 refers to the distance from the lateral load to the axle center.

[0027] Furthermore, in step S3, the specific method for calculating the vertical acceleration of the wheel tyre is as follows:

[0028] S31. Subtract the centrifugal acceleration from the accelerations measured by two adjacent sensors to eliminate the influence of inertial force. Then, synthesize the accelerations after eliminating the influence of inertial force in the vertical direction, and use the sign function to judge the positive and negative directions of the synthesized vertical acceleration, thereby obtaining the vertical acceleration of the wheel tyre.

[0029] S32. Perform arithmetic averaging on the signals collected by the four lateral acceleration sensors to obtain the lateral acceleration of the wheel tyre.

[0030] Further, in step S4, the specific method for calculating the load force of the wheel rubber device is as follows:

[0031] S41. Multiply the vertical stiffness of the wheel rubber device by the vertical displacement of the wheel tyre to obtain the vertical displacement acting force, multiply the lateral stiffness of the wheel rubber device by the lateral displacement of the wheel tyre to obtain the lateral displacement acting force, multiply the vertical damping coefficient of the wheel rubber device by the vertical velocity of the wheel tyre to obtain the vertical damping force, multiply the lateral damping coefficient of the wheel rubber device by the lateral velocity of the wheel tyre to obtain the lateral damping force. Then, add the vertical displacement acting force and the vertical damping force to obtain the vertical suspension force of the rubber device, and add the lateral displacement acting force and the lateral damping force to obtain the lateral suspension force of the rubber device.

[0032] S42. Add the vertical gravity of the wheel tyre to the vertical suspension force of the rubber device, and then subtract the vertical inertial force of the wheel tyre to obtain the wheel-rail vertical force. The vertical inertial force of the wheel tyre is the mass of the wheel tyre multiplied by the vertical acceleration of the wheel tyre. Add the lateral inertial force of the wheel-rail to the lateral suspension force of the rubber device to obtain the wheel-rail lateral force. The lateral inertial force of the wheel-rail is the mass of the wheel tyre multiplied by the lateral acceleration of the wheel tyre.

[0033] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0034] (1). The present invention provides a method for obtaining the rubber load of the compression-shear type elastic wheel of the rail vehicle and the wheel-rail acting force with the aid of sensors. The proposed method converts the data collected by the radial displacement sensor rotating with the wheel into the vertical relative displacement independent of the rotation angle, realizes the indirect measurement and calculation of the vertical stiffness and vertical force of the rubber device, and also realizes the decoupling function of the lateral displacement data, and realizes the indirect measurement and calculation of the lateral stiffness, torsional stiffness and lateral force.

[0035] (2). By using the method disclosed in the present invention to convert the data collected by the acceleration sensor rotating with the wheel into the vertical acceleration data independent of the rotation angle, the indirect measurement and calculation of the wheel-rail acting force are realized. The proposed conversion method of radial-vertical displacement uses the Newton iteration method to solve the high-order characteristic equation to obtain an approximate numerical solution, avoiding the complex root formula and greatly reducing the engineering application difficulty.

[0036] (3) By adopting the method disclosed in the present invention, the dynamic load force borne by the rubber device during the train operation can be calculated, which can be used in engineering to evaluate the service performance of the rubber device and for the vehicle dynamics performance test and evaluation. It is applicable to rail vehicles with compression-shear type elastic wheels, such as urban rail trains, suburban multiple units, high-speed multiple units, railway freight cars, etc., and is also applicable to other elastic wheels with radial stiffness and lateral stiffness. Description of the Drawings

[0037] Figure 1 It is the schematic diagram of the overall framework of the present invention;

[0038] Figure 2 It is the schematic diagram of the left view position for installing the radial displacement sensor of the present invention;

[0039] Figure 3 It is the schematic diagram of the front view position for installing the radial displacement sensor of the present invention;

[0040] Figure 4 It is the schematic diagram of the left view position for installing the lateral displacement sensor of the present invention;

[0041] Figure 5 It is the schematic diagram of the front view position for installing the radial displacement sensor of the present invention;

[0042] Figure 6 It is the schematic diagram of the front view position for installing the acceleration sensor of the present invention;

[0043] Figure 7 It is the schematic diagram of the sectional view position for installing the acceleration sensor of the present invention;

[0044] Figure 8 It is the schematic diagram of loading the vertical load of the present invention;

[0045] Figure 9 It is the schematic diagram of loading the lateral load of the present invention;

[0046] Figure 10 It is the relationship diagram between the vertical load of the wheel rubber device and the vertical wheel-rail force of the present invention;

[0047] Figure 11 It is the relationship diagram between the lateral load of the wheel rubber device and the lateral wheel-rail force of the present invention.

[0048] In the figure, 1 is the tyre; 2 is the rubber device; 3 is the wheel center; 4 is the axle. Detailed Embodiment

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] The accompanying drawings are only for illustrative purposes and cannot be construed as a limitation of this patent;

[0051] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0052] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all the embodiments consistent with the present application. On the contrary, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0053] In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0054] In addition, in the description of the present application, unless otherwise specified, "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The following further elaborates on the present invention with reference to the accompanying drawings and embodiments.

[0055] To solve the limitations of the prior art, this embodiment provides a technical solution. The following further explains the technical solution of the present invention with reference to the accompanying drawings and embodiments.

[0056] The present invention mainly aims at the situation in the prior art that due to the isolation of the rubber device, it is impossible to measure the wheel-rail force of a compression-shear type elastic wheel of a railway vehicle by using a conventional measurement method. And the detection of the wheel-rail interaction force is an important part of vehicle dynamics testing. Therefore, the present invention discloses a calculation method for the rubber load and the wheel-rail interaction force of a compression-shear type elastic wheel of a railway vehicle. The method includes the following steps:

[0057] S1. Install displacement sensors and acceleration sensors on the wheel to collect the relative displacement between the wheel tyre and the wheel center and the vibration acceleration of the wheel tyre. Specifically, the displacement sensors include four radial displacement sensors p1, p2, p3, and p4 arranged circumferentially on the outer or inner side of the wheel tyre (see Appendices Figure 2 and Appendices Figure 3 ), and the measured data are respectively: Δr1, Δr2, Δr3, Δr4. Four lateral displacement sensors p5, p6, p7, and p8 are arranged circumferentially on the outer or inner side of the wheel tyre (see Appendices Figure 4 and Appendices Figure 5 ). The acceleration sensors adopt four two-way vibration acceleration sensors p9, p 10 , p 11 , and p 12 arranged circumferentially on the inner or outer side of the wheel tyre (see Appendices Figure 6 and Appendices Figure 7 ). The two-way vibration acceleration sensor can be understood as being able to measure the vibration acceleration in two directions, namely the lateral acceleration and the vertical acceleration. The circumferential arrangement can be understood as that the four sensors are on the same circumference. Among them, the included angle between adjacent radial displacement sensors is 90° and the displacement measurement direction is radial. Here, the radial direction means the direction along the perpendicular to the axle, that is, the Z direction in Figure 2 . The included angle between adjacent lateral displacement sensors is 90° and the displacement measurement direction is lateral. Here, the lateral direction means the direction along the parallel to the axle, that is, the y direction in Figure 4 . The included angle between adjacent acceleration sensors is 90° and the measurement directions include the radial direction and the axial direction along the parallel to the axle axis, that is, the Z' direction and the y direction in Figure 7 .

[0058] S2. Adopt a bench test or a finite element simulation method to conduct a vertical loading test and a lateral loading test on the elastic wheel, and calculate the vertical stiffness, lateral stiffness, and torsional stiffness of the wheel rubber device by using the data collected in step S1. Specifically, apply a vertical load and a lateral load to the wheel, obtain the radial displacement change amount through the radial displacement sensor, and calculate the vertical stiffness of the wheel rubber device according to the vertical load and the radial displacement change amount. Obtain the lateral displacement change amount through the lateral displacement sensor, and calculate the lateral stiffness and torsional stiffness of the wheel rubber device according to the lateral load and the lateral displacement change amount. The specific method is as follows:

[0059] The specific method for calculating the vertical stiffness of the wheel rubber device is:

[0060] S211, according to the change of the position coordinates of two adjacent sensors before and after vertical loading, the displacement Δr of the i-th radial displacement sensor is obtained respectively. i and the jth radial displacement sensor displacement Δr j The mathematical expression of the wheel rim is obtained by combining these two mathematical expressions to obtain the function f(Δz i ), and list the function f(Δz i ). Finally, the Newton iteration method is used to obtain the vertical displacement Δz of the wheel rim. i Approximate numerical solution, and then the four Δz i The final tire vertical displacement Δz is obtained by taking the average value. Specifically, according to formulas (1) to (4), the Newton iteration method is used to obtain an approximate numerical solution to calculate the tire vertical displacement Δz:

[0061]

[0062] f′(Δz i )=8(Δz i ) 3 -4(C i +C j +2(ΔR0) 2 )(Δz i ) (2);

[0063]

[0064] Where ΔR0=R r -R c , R r is the radius of the installation position of the radial displacement sensor at one end of the wheel rim, R c is the radius of the installation position of the radial displacement sensor at one end of the wheel center, C i =(Δr i ) 2 -(ΔR0) 2 , Δr i is the radial displacement measured by the i-th radial displacement sensor, C j =(Δr j ) 2 -(ΔR0) 2 , Δr jis the radial displacement measured by the j-th radial displacement sensor, (i, j) = {(1, 2), (2, 3), (3, 4), (4, 1)}, n represents the number of iterations, n is an integer, it can be understood here that the value of n depends on the accuracy required by the iterative calculation of formula (3), and the threshold of the iteration error is limited to 0.001mm. The basic principle of establishing the characteristic formula (1) here is: according to the change of the position coordinates of the two adjacent sensors before and after the vertical loading, the displacement Δr of the i-th radial displacement sensor is obtained respectively. i and the jth radial displacement sensor displacement Δr j By combining the two mathematical expressions, we can get formula (1):

[0065] S212. Calculate the vertical stiffness of the wheel rubber device: Substitute the vertical load F V Starting from 10 kN, the load is gradually increased to 1.5 times of the static wheel weight at intervals of 10 kN. After each loading, the vertical displacement Δz is calculated using the method shown in step S211, and then F V The vertical stiffness K is obtained by linear interpolation of the vertical displacement Δz wz .

[0066] The specific method for calculating the lateral stiffness and torsional stiffness of the wheel rubber device is:

[0067] S221, collecting displacement data Δy1, Δy2, Δy3, Δy4 of the initial state of four lateral displacement sensors, as well as displacement data Δy1′, Δy2′, Δy3′, Δy4′ after loading the lateral load, and calculating the lateral relative displacement of the four detection points, dy1=Δy1′-Δy1, dy2=Δy2′-Δy2, dy3=Δy3′-Δy3, dy4=Δy4′-Δy4;

[0068] S222, set the lateral displacement of the wheel tyre under the lateral load as a harmonic function, and include the sine and cosine terms in the mathematical expressions of the lateral displacement of the two sensors separated by 90 degrees, and then obtain the lateral displacement equation of the two adjacent sensors based on the principle that the sum of the squares of sine and cosine equals 1. Use the conventional quadratic equation root-finding formula to solve the displacement equation, and obtain the lateral displacement dy0 caused by the pure lateral force. Substitute dy0 into the lateral displacement equation to obtain the maximum lateral displacement dy of the wheel tyre max The maximum lateral displacement caused by the pure bending moment is (dy max -dy0), specifically, according to formulas (5-1) to (5-3) and (6-1) to (6-3), the maximum lateral displacement caused by the decoupled lateral force and pure bending moment is:

[0069]

[0070] or

[0071]

[0072] or

[0073]

[0074] or

[0075]

[0076] or

[0077]

[0078] where dy0 is the lateral displacement caused by the pure lateral force, and dy max is the maximum lateral displacement of the wheel tyre. The maximum lateral displacement caused by the pure bending moment is (dy max -dy0). Here, it should be explained that both the lateral force and the pure bending moment are caused by the lateral load applied to the wheel tyre; the basic principle for establishing the above formulas (5-1) to (5-3) and formulas (6-1) to (6-3): assume the lateral displacement of the wheel tyre under the lateral load as a harmonic function, then the mathematical expressions of the lateral displacements of two sensors spaced 90 degrees apart respectively include sine and cosine terms. According to the principle that the sum of the squares of sine and cosine is 1, the lateral displacement formulas for two adjacent sensors can be obtained.

[0079] S223. Calculate the lateral stiffness and the roll-torsion stiffness of the rubber device:

[0080] S2231. Apply the lateral load F H starting from 10 kN and increasing it step by step at an interval of 10 kN to 1.2 times the static wheel weight. After each load application, calculate the vertical displacement amounts dy0, dy max , (dy max -dy0) using the method shown in step S222. Then, linearly interpolate the lateral load F H and the lateral relative displacement dy0 to obtain the lateral stiffness K wy of the rubber device;

[0081] S2232. Assume the radius of the position of the lateral displacement sensor on the wheel tyre is R yr . The angle of torsional deformation is equal to the maximum lateral displacement caused by the bending moment divided by the radius of the installation position of the lateral displacement sensor on the wheel tyre. Then the angle of torsional deformation is:

[0082]

[0083] where the maximum lateral displacement caused by the pure bending moment is (dy max-dy0), where dy0 is the lateral displacement caused by the pure lateral force.

[0084] S2233. Interpolate linearly the additional bending moment M H of the lateral force and the torsional deformation angle to obtain the torsional stiffness where M H = F H × r0, F H refers to the lateral load, and r0 refers to the distance from the lateral load to the center of the axle.

[0085] S3. Conduct a track test on the vehicle. Here, it should be explained that, different from the bench test, the track test is an actual track test according to the working conditions specified in the national standard, collecting the displacement and vibration data of the wheels, and calculating the vertical acceleration and lateral acceleration of the wheel tire; the specific method for calculating the vertical acceleration of the wheel tire is as follows:

[0086] S31. Subtract the centrifugal acceleration from the accelerations measured by two adjacent sensors to eliminate the influence of inertial force; then synthesize the accelerations after eliminating the influence of inertial force in the vertical direction, and use the sign function to judge the positive and negative directions of the synthesized vertical acceleration, thereby obtaining the vertical acceleration of the wheel tire. Specifically, calculate the vertical acceleration of the wheel tire according to the following formulas (8) - (12):

[0087]

[0088] where Z″ wrL(R) is the vertical acceleration of the left or right wheel tire. Here, it can be understood that except for the data detected by the sensors being different for the left and right wheel tires, the calculation method of the vertical acceleration is the same. Therefore, Z″ wrL(R) is used to represent the vertical acceleration of the left or right wheel tire. ω is the angular velocity of the wheel rotation, a rp9 , a rp10 , a rp11 , a rp12 are the radial accelerations of the four acceleration sensors, sign(·) represents the positive and negative sign of the value inside the parentheses, and r p refers to the distance from the acceleration sensor to the center of the axle. The basic principle for establishing formulas (9) - (12) is: subtract the centrifugal acceleration from the accelerations measured by two adjacent sensors to eliminate the influence of inertial force, then synthesize the vertical components of the accelerations, and use the sign function to judge the direction of the acceleration.

[0089] S32. Take the arithmetic mean of the signals collected by the four lateral acceleration sensors to obtain the lateral acceleration of the wheel tire. Specifically, calculate the lateral acceleration of the wheel tire according to the following formula (13):

[0090]

[0091] Among them, Y″ wrL(R) is the vertical acceleration of the left or right wheel tyre, a yp9 , a yp10 , a yp11 , a yp12 are the lateral accelerations detected by four acceleration sensors.

[0092] S4. Calculate the load force, wheel-rail vertical force and wheel-rail lateral force of the wheel rubber device.

[0093] The specific method for calculating the load force of the wheel rubber device is that the load force here refers to the vertical suspension force and lateral suspension force of the wheel tyre:

[0094] S41. Multiply the vertical stiffness of the wheel rubber device by the vertical displacement of the wheel tyre to obtain the vertical displacement acting force, multiply the lateral stiffness of the wheel rubber device by the lateral displacement of the wheel tyre to obtain the lateral displacement acting force, multiply the vertical damping coefficient of the wheel rubber device by the vertical velocity of the wheel tyre to obtain the vertical damping force, multiply the lateral damping coefficient of the wheel rubber device by the lateral velocity of the wheel tyre to obtain the lateral damping force, then add the vertical displacement acting force and the vertical damping force to obtain the vertical suspension force of the rubber device, and add the lateral displacement acting force and the lateral damping force to obtain the lateral suspension force of the rubber device; calculate the vertical suspension force and lateral suspension force of the wheel tyre according to the following formulas (14) - (15):

[0095]

[0096] Among them, F rubVL(R) is the vertical suspension force of the left or right wheel tyre, F rubYL(R) is the lateral suspension force of the left or right wheel tyre, K wz is the vertical stiffness of the wheel rubber device, K wy is the lateral stiffness of the wheel rubber device, Δz L(R) The value of Δz is the vertical displacement Δz of the left or right wheel tyre obtained by substituting the data in the line test into formulas (1) - (4), dy L(R) The value of dy is the lateral displacement dy0 caused by the pure lateral force of the left or right wheel tyre obtained by substituting the data in the line test into formulas (5 - 1) - (5 - 3). Here, Δz L(R) and dy L(R) It is particularly emphasized that the data in the line test is used because the values of Δz and dy0 correspond to the values in the bench test, and the values measured by the vertical displacement sensor and lateral displacement sensor in the line test and bench test are definitely different. Therefore, the Δz and dy0 in the bench test correspond to the Δz L(R) and dy L(R), Δz L(R) ′, dy L(R) ′ are the first derivatives of Δz L(R) , dy L(R) respectively, that is, the vertical speed of the wheel tyre and the lateral speed of the wheel tyre. C wz , C wy are the vertical damping coefficient and the lateral damping coefficient of the rubber, where the subscripts L and R represent the left wheel and the right wheel respectively. The basic principle for establishing formulas (14) - (15): The basic principle for calculating the suspension force in the theory of railway vehicle dynamics.

[0097] S42. Add the vertical gravity of the wheel tyre to the vertical suspension force of the rubber device, and then subtract the vertical inertial force of the wheel tyre to obtain the vertical wheel-rail force. The vertical inertial force of the wheel tyre is the mass of the wheel tyre multiplied by the vertical acceleration of the wheel tyre; add the lateral inertial force of the wheel-rail to the lateral suspension force of the rubber device to obtain the lateral wheel-rail force. The lateral inertial force of the wheel-rail is the mass of the wheel tyre multiplied by the lateral acceleration of the wheel tyre. Calculate the vertical wheel-rail force and the lateral wheel-rail force of the wheel according to the following formulas (16) - (17):

[0098]

[0099]

[0100] Among them, P L(R) is the vertical wheel-rail force of the left wheel or the right wheel, Q L(R) is the lateral wheel-rail force of the left wheel or the right wheel, M wr is the mass of the wheel tyre, g is the acceleration due to gravity, F rubVL(R) is the vertical suspension force of the left wheel tyre or the right wheel tyre, F rubYL(R) is the lateral suspension force of the left wheel tyre or the right wheel tyre, Z″ wrL(R) is the vertical acceleration of the left wheel tyre or the right wheel tyre, Y″ wrL(R) is the vertical acceleration of the left wheel tyre or the right wheel tyre, where the subscripts L and R represent the left wheel and the right wheel respectively. The basic principle for establishing formulas (16) - (17): The differential equation of wheel tyre vibration established based on vehicle dynamics.

[0101] Example 1

[0102] The example data in this Example 1 is from the calibration test and the line test data.

[0103] The calibration test verification includes the verification of the calculation methods of the vertical displacement and the lateral relative displacement. The calibration test is carried out on the indoor calibration bench, and the line test is carried out on a certain subway line. The displacement sensor installed in the test is of model NS-WY09 with a range of 200 mm; the acceleration sensor is of model ZW9609A with a range of 18 g; the acquisition device is the German IMC data acquisition system.

[0104] (1) The verification method of the vertical relative displacement between the tyre and the wheel center is as follows:

[0105] Known conditions: The radius R of the installation points of the 4 radial displacement sensors p1, p2, p3, and p4 on the tyre r = 333.648 mm, and the radius R of the installation points on the wheel center c = 276.81 mm; The radius R of the installation points of the 4 lateral displacement sensors on the tyre yr = 333.648 mm, and the radius R of the installation points on the wheel center yc = 276.81 mm.

[0106] First, before the calibration test, the initial clearance R of the radial displacement sensor measured c -R r = 56.838 mm. The tyre is vertically loaded through the loading device until the vertical displacement at the top of the tyre is 5 mm. Then, the data of the 4 radial displacement sensors are measured, and the measured displacement data are obtained as Δr1 = 58.379 mm, Δr2 = 61.67 mm, Δr3 = 55.707 mm, and Δr4 = 52.039 mm. Finally, the measured data are substituted into the method proposed by the present invention to verify the accuracy of the vertical displacement estimation method. Set the initial iteration value to 1 mm, and after 7 iterations, the vertical relative displacement of 5.000802 mm is obtained, and the error is less than 10 -6 , and the accuracy fully meets the requirements. The iteration process is shown in Table 1.

[0107] Table 1 Iterative calculation process

[0108]

[0109]

[0110] Substitute the calculation result into the following formula (18) to obtain the angle θ of sensor P1 as 15.5678 degrees. The actual installation angle of sensor p1 is 15.556 degrees, and the angle error is 0.01 degree, and the accuracy fully meets the requirements. Then the installation angle of the adjacent sensor p2 is θ + 90 degrees = 105.5678 degrees, and the result is consistent with the actual situation.

[0111]

[0112] Among them, ΔR0 = R r -R c , R r is the radius of the installation position of the radial displacement sensor on the tyre, R c$r$ is the radius of the installation position of the radial displacement sensor at the wheel center, $\Delta r_1$ is the radial displacement measured by the first radial displacement sensor, and $\Delta z$ is the vertical displacement of the wheel tire.

[0113] (2) The verification method for the decoupling calculation method of the lateral relative displacement between the wheel tire and the wheel center is as follows:

[0114] The initial installation angles of the four lateral displacement sensors p5, p6, p7, and p8 are 0 degrees, 90 degrees, 180 degrees, and 270 degrees respectively.

[0115] First, the wheel tire is laterally loaded through the loading device, and the applied load is 1.2 times the wheel weight (78 kN). After obtaining data from the lateral displacement sensors and processing the data, the lateral relative displacement amounts at the four measuring points are: $dy1 = -2.478$ mm, $dy2 = -0.736$ mm, $dy3 = 1.007$ mm, $dy4 = -0.736$ mm. Solving any one of the formulas (5-1) to (5-3) gives $dy0 = -0.735$ mm.

[0116] Then, rotate the wheel 45 degrees, set the installation angles of the 4 lateral displacement sensors to 45 degrees, 135 degrees, 225 degrees, and 315 degrees respectively, and reload the test. The applied load is 1.2 times the wheel weight (78 kN). After obtaining data from the lateral displacement sensors and processing the data, the lateral relative displacement amounts at the four measuring points are: $dy1 = -1.969449$ mm, $dy2 = 0.49776$, $dy3 = 0.49775$, $dy4 = -1.9694$. According to any one of the formulas (5-1) to (5-3), $dy0 = -0.736$ mm.

[0117] The calculation results in other angle cases are consistent with the above two cases, and $dy0$ is all around -0.735 mm. It can be seen that the formulas (5-1) to (5-3) eliminate the influence of the angle and obtain the lateral displacement $dy0$ caused by the lateral force. Then, substituting $dy0$ into any one of the equations (9) to (12), the maximum lateral displacement is $dy$ max $= 1.008$ mm, and the maximum lateral displacement caused by the pure bending moment is $dy$ max $-dy0 = 1.745$ mm. The results are consistent with the results of separately loading the lateral force and the bending moment, indicating that the decoupling result of the proposed algorithm is correct.

[0118] (3) The calculation examples of the load force of the rubber device and the wheel-rail force are as follows:

[0119] Tests were carried out on the line between two stations of a certain subway section. The train accelerated from the starting acceleration to a maximum of 60 km / h and then decelerated until it stopped. The total time length was 110 seconds. Figure 10 and Figure 11The relationship diagrams between the vertical load of the rubber device and the wheel-rail vertical force, and between the lateral load and the wheel-rail lateral force calculated by the method according to the present invention are respectively given. When in the static state, the wheel-rail vertical force is slightly greater than the vertical force of the rubber device because the wheel-rail vertical force includes the mass of the wheel tire. During the running state, the non-linear characteristics of the load force of the rubber device are obvious, and the fluctuation is greater than that of the wheel-rail vertical force, which is caused by the large non-linear deformation of the rubber. The difference between the wheel-rail lateral force and the lateral load of the rubber device is not significant because the lateral force inertia force caused by the lateral acceleration of the wheel tire is small (measured data shows that the lateral acceleration of the wheel tire mainly fluctuates within the range of plus or minus 1g, and the maximum value does not exceed 2g, so the inertia force does not exceed 1kN), which is not enough to cause a significant difference between the two.

[0120] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0121] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A calculation method for the rubber load and wheel-rail interaction force of a compression-shear type elastic wheel of an orbital vehicle, characterized in that, The method includes the following steps: S1. Install a displacement sensor and an acceleration sensor on the wheel to collect the relative displacement between the wheel tyre and the wheel center and the vibration acceleration of the wheel tyre; S2. Adopt a bench test or a finite element simulation method to conduct a vertical loading test and a lateral loading test on the elastic wheel, and calculate the vertical stiffness, lateral stiffness and torsional stiffness of the wheel rubber device by using the data collected in step S1; S3. Conduct a line test on the vehicle, collect the displacement and vibration data of the wheel, and calculate the vertical acceleration and lateral acceleration of the wheel tyre; S4. Calculate the load force of the wheel rubber device, the vertical wheel-rail force and the lateral wheel-rail force.

2. The calculation method of rubber load and wheel-rail interaction force of a compression-shear type elastic wheel for a rail vehicle according to claim 1, characterized in that In step S1, the displacement sensor includes four lateral displacement sensors arranged circumferentially on the outer or inner side of the wheel tyre and four radial displacement sensors arranged circumferentially on the outer or inner side of the wheel tyre. The acceleration sensor adopts four two-way vibration acceleration sensors arranged circumferentially on the inner or outer side of the wheel tyre. The included angle between adjacent radial displacement sensors is 90° and the displacement measurement direction is radial. The included angle between adjacent lateral displacement sensors is 90° and the displacement measurement direction is lateral. The included angle between adjacent acceleration sensors is 90° and the measurement directions include radial and axial along the axis of the axle.

3. The calculation method of rubber load and wheel-rail interaction force of a compression-shear type elastic wheel for a rail vehicle according to claim 2, characterized in that, In step S2, a vertical load and a lateral load are applied to the wheel. The radial displacement change amount is obtained through the radial displacement sensor, and the vertical stiffness of the wheel rubber device is calculated according to the vertical load and the radial displacement change amount. The lateral displacement change amount is obtained through the lateral displacement sensor, and the lateral stiffness and torsional stiffness of the wheel rubber device are calculated according to the lateral load and the lateral displacement change amount.

4. The calculation method of rubber load and wheel-rail interaction force of a compression-shear type elastic wheel for a rail vehicle according to claim 3, wherein, In step S2, the specific method for calculating the vertical stiffness of the wheel rubber device is: S211, according to the change of the position coordinates of two adjacent sensors before and after vertical loading, the displacement Δr of the i-th radial displacement sensor is obtained respectively. i and the jth radial displacement sensor displacement Δr j The mathematical expression of the wheel rim is obtained by combining these two mathematical expressions to obtain the function f(Δz i ), and list the function f(Δz i ), and finally the Newton iteration method is used to obtain the vertical displacement Δz of the wheel hoop. i Approximate numerical solution, and then the four Δz i Take the average value to get the final wheel hoop vertical displacement Δz; S212. Calculate the vertical stiffness of the wheel rubber device: Apply a vertical load F V starting from 10 kN and increasing it step by step at intervals of 10 kN up to 1.5 times the static wheel weight. After each load application, calculate the vertical displacement Δz using the method shown in step S211 once, and then linearly interpolate F V and the vertical displacement Δz to obtain the vertical stiffness K wz .

5. The calculation method of rubber load and wheel-rail interaction force of a compression-shear type elastic wheel for a rail vehicle according to claim 4, characterized in that, In step S2, the specific methods for calculating the lateral stiffness and torsional stiffness of the wheel rubber device are: S221. Collect the displacement data Δy1, Δy2, Δy3, Δy4 of the four lateral displacement sensors in the initial state and the displacement data Δy1′, Δy2′, Δy3′, Δy4′ after applying the lateral load, and calculate the lateral relative displacement amounts of the four detection points; S222. Set the lateral displacement of the wheel tyre under the action of the lateral load as a harmonic function. The mathematical expressions of the lateral displacements of two sensors spaced 90 degrees apart respectively include sine and cosine terms. Then, according to the principle that the sum of the squares of sine and cosine is 1, the lateral displacement equations of two adjacent sensors are obtained. The displacement equations are solved by using the root formula of the conventional unary quadratic equation to obtain the lateral displacement dy0 caused by the pure lateral force. Substitute dy0 into the lateral displacement equation to obtain the maximum lateral displacement dy of the wheel tyre. max And the maximum lateral displacement caused by the pure bending moment is (dy max - dy0); S223. Calculate the lateral stiffness and roll torsional stiffness of the rubber device: S2231. Apply the lateral load F H Starting from 10 kN, increase the load step by step at intervals of 10 kN up to 1.2 times the static wheel load. After each load application, calculate the vertical displacement dy0 and dy using the method shown in step S222 max , (dy max - dy0), and then linearly interpolate the lateral load F H and the lateral relative displacement dy0 to obtain the lateral stiffness K of the rubber device wy ; S2232. Let the position radius of the lateral displacement sensor on the wheel tyre be R yr , and the torsional deformation angle is equal to the maximum lateral displacement caused by the bending moment divided by the installation position radius of the lateral displacement sensor on the wheel tyre; S2233. Interpolate the additional bending moment M of the lateral force H and the angle of torsional deformation linearly to obtain the torsional stiffness where M H = F H × r0, F H refers to the lateral load, and r0 refers to the distance from the lateral load to the axle center.

6. A calculation method for rubber load and wheel-rail interaction force of a compression-shear type elastic wheel of a rail vehicle according to any one of claims 1-5, characterized in that In step S3, the specific method for calculating the vertical acceleration of the wheel tyre is: S31. Subtract the centrifugal acceleration from the accelerations measured by two adjacent sensors to eliminate the influence of inertial force; then synthesize the accelerations after eliminating the influence of inertial force in the vertical direction, and use the sign function to judge the positive and negative directions of the synthesized vertical acceleration, so as to obtain the vertical acceleration of the wheel tyre; S32. Arithmetically average the signals collected by the four lateral acceleration sensors to obtain the lateral acceleration of the wheel tyre.

7. The calculation method of rubber load and wheel-rail interaction force of a compression-shear type elastic wheel for a rail vehicle according to claim 6, characterized in that, In step S4, the specific method for calculating the load force of the wheel rubber device is: S41. Multiply the vertical stiffness of the wheel rubber device by the vertical displacement of the wheel rim to obtain the vertical displacement acting force. Multiply the lateral stiffness of the wheel rubber device by the lateral displacement of the wheel rim to obtain the lateral displacement acting force. Multiply the vertical damping coefficient of the wheel rubber device by the vertical velocity of the wheel rim to obtain the vertical damping force. Multiply the lateral damping coefficient of the wheel rubber device by the lateral velocity of the wheel rim to obtain the lateral damping force. Then add the vertical displacement acting force and the vertical damping force to obtain the vertical suspension force of the rubber device. Add the lateral displacement acting force and the lateral damping force to obtain the lateral suspension force of the rubber device; S42. Add the vertical gravity of the wheel rim, the vertical suspension force of the rubber device, and then subtract the vertical inertial force of the wheel rim to obtain the wheel-rail vertical force. The vertical inertial force of the wheel rim is the mass of the wheel rim multiplied by the vertical acceleration of the wheel rim. Add the lateral inertial force of the wheel-rail and the lateral suspension force of the rubber device to obtain the wheel-rail lateral force. The lateral inertial force of the wheel-rail is the mass of the wheel rim multiplied by the lateral acceleration of the wheel rim.

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