Train aerodynamic force and wheel-rail force distributed measuring device and method

Abstract

The invention relates to the technical field of rail traffic testing, and discloses a train aerodynamic force and wheel-rail force distributed measuring device and method.The device comprises multiple sets of rail roadbed modules detachably arranged on the ground of a wind tunnel test section in sequence, and the rail roadbed modules comprise multiple sets of roadbeds connected in sequence; each group of subgrade is provided with a first track matched with a train model, and at least one group of subgrade of each group of track subgrade module is provided with a mounting groove; the sensor module comprises a sensor mounting seat and a sensor, the sensor mounting seat is detachably arranged in the mounting groove, and a second track matched with the train model is arranged on the sensor mounting seat; wheels of the train model are fixedly connected with the second track. According to the invention, a specific distributed sensor arrangement scheme is adopted to be integrated with a modularized track roadbed module, and a special system calibration and data processing method is combined, so that the accurate distributed measurement and synthesis of the train load are realized.

Description

Technical Field

[0001] This invention relates to the field of rail transit testing technology, specifically to a distributed measurement device for train aerodynamics and wheel-rail forces. Background Technology

[0002] In the study of aerodynamic characteristics of high-speed trains, wind tunnel testing is an important method. Traditional wind tunnel testing usually uses a scaled-down model in conjunction with a single, embedded six-component aerodynamic balance for measurement. Although this method can obtain the overall aerodynamic forces and moments of the model (such as drag, lift, lateral force, pitching moment, yaw moment, and roll moment), it has the following significant drawbacks: (1) Range and load-bearing limitations: The range and load-bearing capacity of a single aerodynamic balance are limited, making it difficult to directly apply to wind tunnel tests of actual vehicles or large-mass scaled-down models. For actual vehicle tests, it is extremely difficult to achieve in engineering to "lift" and rigidly support a train body weighing tens of tons using a single balance. (2) Inability to measure distributed forces and wheel-rail forces: Traditional single balances measure the integrated forces and moments acting on their installation center, and cannot distinguish and measure the aerodynamic load distribution of different parts of the train (such as the head car and bogie area), let alone directly measure the wheel-rail forces (vertical force and lateral force) that are crucial during train operation. Wheel-rail forces are key parameters for studying train running stability and anti-overturning performance. (3) Installation limitations and interference: The embedded balance needs to be rigidly connected to the model, resulting in a complex installation structure and high requirements for the internal space of the model. In actual vehicle testing, it is difficult to find a suitable installation space and support structure. In addition, structures such as support rods may interfere with the flow field and affect the measurement accuracy.

[0003] Therefore, there is an urgent need for a new type of measurement device that can be applied to real vehicles or large-mass models and can simultaneously acquire the overall aerodynamic force and wheel-rail force distribution. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a distributed measurement device and method for train aerodynamic force and wheel-rail force, which has a range and load-bearing capacity suitable for actual vehicles or large-mass models, and can simultaneously acquire the overall aerodynamic force and wheel-rail force distribution.

[0005] In a first aspect, the present invention provides a distributed measurement device for train aerodynamic forces and wheel-rail forces, comprising: Multiple sets of track roadbed modules are detachably installed on the ground of the wind tunnel test section. Each track roadbed module includes multiple sets of roadbeds connected in sequence. Each set of roadbeds is provided with a first track that matches the train model. At least one set of roadbeds in each set of track roadbed modules is provided with an installation groove. The sensor module includes a sensor mounting base and a sensor. The sensor mounting base is detachably installed in a mounting slot. The sensor mounting base is provided with a second track that matches the train model. The first track is connected to and aligned with the second track. The sensor is installed at the bottom of the sensor mounting base. A train model, wherein the wheels of the train model are fixedly connected to a second track.

[0006] As a further improvement to the above technical solution: The sensor mounting base is detachably connected to the mounting groove by bolts, and the lower surface of the sensor mounting base is rigidly connected to the sensor by bolts.

[0007] As a further improvement to the above technical solution: The roadbed sections described above are all positioned to each other using mortise and tenon joints and fixed together with bolts; Adjacent roadbeds are also connected by a maze-like interlocking mechanism.

[0008] As a further improvement to the above technical solution: The roadbed with the installation groove is made of aluminum plate with a thickness of not less than 20mm; the roadbed without the installation groove is made of engineering plastic material and designed with a hollow grid structure. The sensor mounting base is made of stainless steel.

[0009] As a further improvement to the above technical solution: The track subgrade module is also fixed to the floor of the wind tunnel test section via a base plate; The heads of the roadbeds at both ends are equipped with guide slopes with an inclination of 5°±0.5°.

[0010] As a further improvement to the above technical solution: The sensor is a three-dimensional force sensor; The sensor mounting base is also equipped with at least four leveling screws for adjusting the levelness of the sensor mounting base.

[0011] As a further improvement to the above technical solution: The wheels of the train model are bonded to the second track with epoxy resin structural adhesive, forming a force transmission path without mechanical gaps.

[0012] Secondly, the present invention provides a distributed measurement method for train aerodynamic forces and wheel-rail forces, the method being applied to the distributed measurement device for train aerodynamic forces and wheel-rail forces as described above, the method comprising: S1: Equipment preparation. Based on the size and wheelbase of the train model, select the appropriate length of track roadbed module and install the 8 three-dimensional force sensors onto the sensor mounting base respectively. S2: Subgrade installation and leveling. On the floor of the wind tunnel test section, install the subgrade support brackets according to the design position, splice the subgrade on the brackets in sequence, and use a level to level the entire track surface to ensure that the levelness error is less than 0.1°. S3: Sensor integration. The sensor mount with the sensor is installed in the mounting groove of the roadbed. The four leveling screws on the bottom of the sensor mount ensure that the track lines on the upper surface of all sensor mounts are aligned and level. S4: Train model installation. Use hoisting equipment to place the train model smoothly on the roadbed, and use an optical positioning device to assist in placing each wheel on the second track of the corresponding sensor mounting base. Use special clamps and adhesives to fix the wheels to the second track, and check and ensure that the train model has no additional lateral tilt, pitch and roll. S5: System calibration. Static loading calibration is performed before the wind tunnel is started. Known standard loads are applied vertically, longitudinally, and laterally at the center of gravity of the train model. The outputs of each sensor are collected, and the calibration coefficient matrix is ​​calculated through data processing software. S6: Wind tunnel test and data acquisition. Start the wind tunnel and run it according to the set wind speed and wind direction angle conditions. The data acquisition system simultaneously collects the triaxial force signals from 8 sensors. S7: Data processing. After the test is completed, the data processing software uses the calibration coefficient matrix to correct the original data, synthesizes the six-part force dynamics of the whole vehicle in real time or post-processing, and directly outputs the wheel-rail force time history data of each measuring point.

[0013] As a further improvement to the above technical solution: The system calibration specifically includes: a. Static weights are applied longitudinally, laterally, and vertically to the roof and the front, middle, and rear sides of the model vehicle, respectively, and the static weight application includes at least three force levels; b. Collect sensor data under all loading conditions; c. Data processing: Import the data into specialized software, run the third-order multiple regression algorithm, and calculate the calibration coefficient matrix. d. Verify the calibration by applying a static load at another loading point and comparing the calibrated output value with the theoretical value to ensure that the verification error is less than 5%.

[0014] As a further improvement to the above technical solution: The data processing specifically includes: The overall aerodynamic force is synthesized by summing the longitudinal force components, vertical force components, and lateral force components measured by the eight sensors. The synthesis of overall aerodynamic moments, including calculation of roll moment and pitch moment. and Yaw moment; The wheel-rail force is obtained by taking the three-dimensional force output of each sensor as the three-dimensional wheel-rail force at the corresponding wheelset contact point.

[0015] Compared with the prior art, the advantages of the present invention are as follows: (1) A distributed measurement device for train aerodynamics and wheel-rail forces according to the present invention includes: multiple sets of track roadbed modules that are detachably arranged sequentially on the ground of a wind tunnel test section, each track roadbed module including multiple sets of roadbeds connected sequentially, each set of roadbeds having a first track matching the train model, and at least one set of roadbeds in each set of track roadbed modules having an installation groove; a sensor module including a sensor mounting base and a sensor, the sensor mounting base being detachably arranged in the installation groove, the sensor mounting base having a second track matching the train model, the first track and the second track being connected and aligned, the sensor being arranged at the bottom of the sensor mounting base; and a train model, the wheels of the train model being fixedly connected to the second track. The present invention achieves accurate distributed measurement and synthesis of train loads by integrating a specific distributed sensor arrangement scheme with modular track roadbed modules, combined with dedicated system calibration and data processing methods.

[0016] (2) Breaking through the load-bearing limitation, the distributed measurement device for train aerodynamics and wheel-rail forces of the present invention adopts distributed multi-sensor load-bearing, which disperses the overall load and completely solves the problem that the single balance range is insufficient and cannot support the wind tunnel test of the actual vehicle or heavy-load model.

[0017] (3) With rich measurement functions, the distributed measurement device for train aerodynamics and wheel-rail forces of the present invention can not only realize the aerodynamic measurement of the six components of the whole vehicle with the same effect as the traditional single-day measurement, but also simultaneously and directly measure the three-dimensional wheel-rail forces at each wheel, providing unprecedented comprehensive data for the study of train aerodynamic performance and operation safety (especially crosswind stability and anti-overturning).

[0018] (4) The structure is modular and highly adaptable. The train aerodynamic and wheel-rail force distributed measurement device of the present invention is easy to install, transport and modify through the design of detachable segmented track roadbed, and can be flexibly adapted to train models of different models and wheelbases.

[0019] (5) High measurement accuracy: The distributed measurement device for train aerodynamics and wheel-rail forces of the present invention ensures the accuracy of force transmission path through precise mechanical structure design, and effectively eliminates errors by combining system calibration algorithm. The measurement accuracy can meet or even exceed the qualified or advanced indicators of relevant national standards (such as GJB2244A-2011).

[0020] (6) It has little interference with the flow field. The sensor of the distributed measurement device for train aerodynamic force and wheel-rail force of the present invention is embedded in the roadbed and the measurement structure is not exposed. Compared with the external support rod of the traditional balance, the interference with the wind tunnel flow field is significantly reduced. Attached Figure Description

[0021] Figure 1 This is an axial view of a distributed measurement device for train aerodynamics and wheel-rail forces according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the installation of the sensor mounting base and the roadbed in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a set of track subgrade modules in an embodiment of the present invention; Figure 4 This is a schematic diagram of the roadbed structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the sensor mounting base in an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the synthesis of the overall aerodynamic force and the overall aerodynamic torque in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Track subgrade module, 1.1, Subgrade, 1.2, First track, 1.3, Mounting slot; 2. Sensor module, 2.1, Sensor mounting base, 2.2, Sensor, 2.3, Second track; 3. Train model. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1-5 As shown, this embodiment provides a distributed measurement device for train aerodynamics and wheel-rail forces, including: multiple sets of track roadbed modules 1 that are detachably and sequentially installed on the ground of a wind tunnel test section. Each track roadbed module 1 includes multiple sets of roadbeds 1.1 connected in sequence. Each set of roadbeds 1.1 is provided with a first track 1.2 that matches the train model 3, and at least one set of roadbeds 1.1 in each set of track roadbed modules 1 is provided with a mounting groove 1.3; a sensor module 2, including a sensor mounting base 2.1 and a sensor 2.2 (a three-dimensional force sensor in this embodiment). The sensor mounting base 2.1 is detachably installed in the mounting groove 1.3. The sensor mounting base 2.1 is provided with a second track 2.3 that matches the train model 3. The first track 1.2 and the second track 2.3 are connected and aligned. The sensor 2.2 is located at the bottom of the sensor mounting base 2.1; and a train model 3, with the wheels of the train model 3 fixedly connected to the second track 2.3.

[0025] This embodiment, through the aforementioned setup, transforms the traditional "centralized single-point integration measurement" into "distributed multi-point direct measurement and synthesis," fundamentally solving the feasibility problem of large-load measurement. A modular, detachable trackbed 1.1, designed to match distributed measurement, integrates multiple functions such as sensor 2.2 installation, force transmission, model support, and streamlined flow guidance, serving as the core load-bearing structure enabling the device's implementation. Furthermore, on the same hardware device, simultaneous high-precision measurement of the vehicle's aerodynamic forces and distributed wheel-rail forces was achieved for the first time.

[0026] In this embodiment, the track subgrade module 1 is detachable, serving as the load-bearing and installation foundation for the entire device. It employs a segmented design, with each subgrade segment 1.1 positioned using mortise and tenon joints and bolted together. The critical load-bearing sections corresponding to the wheel positions of the train model 3 are made of high-strength aluminum plate (preferably Q355D in this embodiment), with a thickness of not less than 20mm, to ensure local rigidity and measurement stability, avoiding measurement errors caused by deformation of the subgrade 1.1. The remaining non-critical sections are made of lightweight engineering plastic (preferably nylon in this embodiment) with a hollow mesh structure to control overall quality. A simulated track is laid on the upper surface of the subgrade 1.1, with a 5°±0.5° guide slope at the head to reduce wind resistance. Labyrinthine interlocking buckles are provided at the joints of each segment to ensure the continuity and smoothness of the track surface, effectively preventing airflow from entering the sensor 2.2 mounting cavity during testing. The entire subgrade 1.1 module is fixed to the floor of the wind tunnel test section via a base plate.

[0027] The sensor mounting base 2.1 in this embodiment consists of a top cover plate with a track, made of stainless steel. The lower surface of the sensor mounting base 2.1 is rigidly connected to the sensor 2.2 probe via hexagonal socket head cap screws, and the track on the upper surface is strictly aligned with the track of the roadbed 1.1. The sensor mounting base 2.1 is designed with four leveling screws, used to adjust the upper surface of the sensor 2.2 (i.e., the track surface) to a horizontal level (levelness ≤ 0.05°) during installation using a high-precision inclinometer. The train wheels are bonded and fixed to the track surface of the sensor mounting base 2.1 with high-strength epoxy resin structural adhesive, forming a force transmission path without mechanical backlash. An assembly gap of approximately 2mm is reserved between the sensor mounting base 2.1 and the main body of the roadbed 1.1 to facilitate installation and leveling.

[0028] like Figure 6 As shown, this embodiment also provides a distributed measurement method for train aerodynamic forces and wheel-rail forces. The effectiveness of the measurement device in this embodiment also relies on a complete installation, calibration, and data processing process. Its measurement principle is based on the theorem of composition and translation of force and torque, and coupling errors are eliminated through a specific calibration algorithm. The method is applied to the distributed measurement device for train aerodynamic forces and wheel-rail forces as described above, and the method includes: S1: Device preparation. Based on the size and wheelbase of the train model 3, select a track roadbed module 1 of appropriate length, and install 8 three-dimensional force sensors 2.2 (for trains with different numbers of axles (such as six-axle or twelve-axle trains, 6 or 12 sensors 2.2 can be arranged accordingly) on the sensor mounting base 2.1 respectively; S2: Roadbed 1.1 installation and leveling. On the floor of the wind tunnel test section, install the roadbed 1.1 support brackets according to the design position, splice the roadbed 1.1 on the brackets in sequence, and use a high-precision electronic level to level the entire track surface to ensure that the levelness error is less than 0.1°. S3: Sensor 2.2 integration. Install the sensor mounting base 2.1 with sensor 2.2 in the mounting groove 1.3 of the roadbed 1.1. Using the four leveling screws on the bottom of the sensor mounting base 2.1 and a tiltmeter with an accuracy of 0.02°, adjust the track surface on the sensor mounting base 2.1 to be horizontal one by one, and ensure that all 8 track surfaces are at the same height plane (height difference ≤ 0.1mm). Ensure that the track lines on the upper surface of all sensor mounting bases 2.1 are aligned and horizontal. S4: Train model 3 installation: Use hoisting equipment to place train model 3 stably on the roadbed 1.1, and use an optical positioning device to assist in positioning each wheel on the second track 2.3 of the corresponding sensor mounting base 2.1. Use special clamps and high-strength epoxy resin to fix the wheels to the second track 2.3 (in addition to adhesive bonding, precision mechanical buckles or bolts can also be used to connect the wheels to the sensor mounting base 2.1, but the ease of disassembly and assembly and interference with the measurement signal must be considered). Check and ensure that train model 3 has no additional lateral deviation, pitch and roll, and maintain a nominal gap of 8mm between the lower edge of the wheel and the track surface to avoid non-test contact; Because multiple sensors 2.2 are mechanically coupled in a complex structure, when only one direction is loaded, sensors 2.2 in other directions will also output signals. Simple summation will lead to errors, so system-level calibration is necessary.

[0029] S5: System calibration. Static loading calibration is performed before the wind tunnel is started. Multiple loading points (such as the roof and side walls) are selected on the train model 3. A series of known standard weight loads (such as 1kg, 3kg, and 5kg) are applied along the longitudinal, transverse, and vertical directions respectively. The three-dimensional raw outputs of all 8 sensors 2.2 under each working condition are recorded. A multivariate regression decoupling model is established, using calibration data to establish the mapping relationship between system inputs (24 sensors, 2.2 raw output channels) and outputs (3 resultant forces and 3 resultant moments). A multivariate multi-order polynomial regression algorithm is employed for system identification. Taking one direction (e.g., longitudinal resultant force Fx) as an example, the calibration model is as follows: Fx corrected =a0+Σ(a i *V i )+ΣΣ(b ij *V i *V j )+ΣΣΣ(c ijk *V i *V j *V k ); Among them, Fx corrected V represents the corrected longitudinal resultant force. i a represents the raw voltage output of the i-th sensor 2.2. i b ij c ijk The regression coefficients to be determined are denoted as . By regressing the data under pitch, yaw, and roll moment loading conditions together, a complete decoupling calibration coefficient matrix containing hundreds (e.g., 455) coefficients can be obtained.

[0030] Verification showed that applying this calibration coefficient matrix to process another set of independent static load test data could significantly reduce measurement deviations (such as 8.376% deviation under combined force conditions in ground loading tests) to within the allowable range for engineering (such as 2.44%).

[0031] S6: Wind tunnel test and data acquisition. Start the wind tunnel and run it according to the set wind speed and wind direction angle. The data acquisition system synchronously acquires the triaxial force signals of 8 sensors 2.2 at a frequency higher than 1000Hz. After each condition stabilizes, data is continuously acquired for a certain period of time. During wind tunnel operation, the data acquisition system synchronously acquires signals from all sensors (2.2). The data processing software first applies the aforementioned system calibration coefficient matrix to decouple and correct the raw data in real time, eliminating interference between channels. Then, using the corrected forces at each point and precise geometric parameters, the system synchronously calculates and outputs the six-component aerodynamic forces (Fx, Fy, F) of the entire vehicle according to the following synthesis formula. z M x M y M z (and the three-dimensional wheel-rail forces at the eight wheel-rail contact points.)

[0032] Synthesis of overall aerodynamic forces: Aerodynamic drag (resultant force F) x ): The longitudinal force components measured by the eight sensors in section 2.2 are summed, i.e., Fx =F x1 +F x2 +F x3 +F x4 +F x5 +F x6 +F x7 +F x8 .

[0033] Aerodynamic lift (resultant force F) z ): The vertical force components measured by the eight sensors in section 2.2 are summed, i.e., F z =F z1 +F z2 +F z3 +F z4 +F z5 +F z6 +F z7 +F z8 .

[0034] Aerodynamic lateral force (resultant force F) y ): The lateral force components measured by the eight sensors in section 2.2 are summed, i.e., F y =F y1 +F y2 +F y3 +F y4 +F y5 +F y6 +F y7 +F y8 .

[0035] Synthesis of overall aerodynamic torque: Rolling torque M x : M x =-F Y1 ·hF Y2 ·hF Y3 ·hF Y4 ·hF Y5 ·hF Y6 ·hF Y7 ·hF Y8 ·h+F Z1 ·d / 2-F Z2 ·d / 2+F Z3 ·d / 2-F Z4 ·d / 2+F Z5 ·d / 2-F Z6 ·d / 2+F Z7 ·d / 2-F Z8 ·d / 2; Pitch moment M y : M y =FX1 ·h+F X2 ·h+F X3 ·h+F X4 ·h+F X5 ·h+F X6 ·h+F X7 ·h+F X8 ·hF Z1 ·(L+e) / 2-F Z2 ·(L+e) / 2-F Z3 ·(Le) / 2-F Z4 ·(Le) / 2+F Z5 ·(Le) / 2+F Z6 ·(Le) / 2+F Z7 ·(L+e) / 2+F Z8 ·(L+e) / 2; Yaw moment M z : M z =M Z =-F X1 ·d / 2+F X2 ·d / 2-F X3 ·d / 2+F X4 ·d / 2-F X5 ·d / 2+F X6 ·d / 2-F X7 ·d / 2+F X8 ·d / 2+F Y1 ·(L+e) / 2+F Y2 ·(L+e) / 2+F Y3 ·(Le) / 2+F Y4 ·(Le) / 2-F Y5 ·(Le) / 2-F Y6 ·(Le) / 2-F Y7 ·(L+e) / 2-F Y8 ·(L+e) / 2.

[0036] Where d is the lateral center distance of the sensor, e is the longitudinal center distance of the sensor, L is the scaled-down train distance, and h is the height difference between the sensor and the balance.

[0037] S7: Data processing. After the test is completed, the data processing software uses the calibration coefficient matrix to correct the original data, synthesizes the six-part force dynamics of the whole vehicle in real time or post-processing, and directly outputs the wheel-rail force time history data of each measuring point.

[0038] The system calibration specifically includes: a. Static weights are applied longitudinally, laterally, and vertically to the roof and the front, middle, and rear sides of the model vehicle, respectively, and the static weight application includes at least three force levels; b. Collect data from sensor 2.2 under all loading conditions; c. Data processing: Import the data into specialized software, run the third-order multiple regression algorithm, and calculate the calibration coefficient matrix. d. Verify the calibration by applying a static load at another loading point and comparing the calibrated output value with the theoretical value to ensure that the verification error is less than 5%.

[0039] The data processing specifically includes: The overall aerodynamic force is synthesized by summing the longitudinal force components, vertical force components, and lateral force components measured by the eight sensors in section 2.2. The synthesis of overall aerodynamic moments, including calculation of roll moment and pitch moment. and Yaw moment; Direct acquisition of wheel-rail force: The triaxial force output (Fx, Fy, Fz) of each sensor 2.2 represents the three-dimensional wheel-rail force at the corresponding wheelset contact point.

[0040] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the inventive concept should also be considered within the scope of protection of the present invention.

Claims

1. A distributed measurement device for train aerodynamic forces and wheel-rail forces, characterized in that, include: Multiple sets of track roadbed modules are detachably installed on the ground of the wind tunnel test section. Each track roadbed module includes multiple sets of roadbeds connected in sequence. Each set of roadbeds is provided with a first track that matches the train model. At least one set of roadbeds in each set of track roadbed modules is provided with an installation groove. The sensor module includes a sensor mounting base and a sensor. The sensor mounting base is detachably installed in a mounting slot. The sensor mounting base is provided with a second track that matches the train model. The first track is connected to and aligned with the second track. The sensor is installed at the bottom of the sensor mounting base. A train model, wherein the wheels of the train model are fixedly connected to a second track.

2. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 1, characterized in that, The sensor mounting base is detachably connected to the mounting groove by bolts, and the lower surface of the sensor mounting base is rigidly connected to the sensor by bolts.

3. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 2, characterized in that, The roadbed sections described above are all positioned to each other using mortise and tenon joints and fixed together with bolts; Adjacent roadbeds are also connected by a maze-like interlocking mechanism.

4. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 3, characterized in that, The roadbed with the installation groove is made of aluminum plate with a thickness of not less than 20mm; the roadbed without the installation groove is made of engineering plastic material and designed with a hollow grid structure. The sensor mounting base is made of stainless steel.

5. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 4, characterized in that, The track subgrade module is also fixed to the floor of the wind tunnel test section via a base plate; The heads of the roadbeds at both ends are equipped with guide slopes with an inclination of 5°±0.5°.

6. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 5, characterized in that, The sensor is a three-dimensional force sensor; The sensor mounting base is also equipped with at least four leveling screws for adjusting the levelness of the sensor mounting base.

7. The distributed measurement device for train aerodynamics and wheel-rail forces according to claim 6, characterized in that, The wheels of the train model are bonded to the second track with epoxy resin structural adhesive, forming a force transmission path without mechanical gaps.

8. A distributed measurement method for train aerodynamic forces and wheel-rail forces, characterized in that, The method is applied to the distributed measurement device for train aerodynamics and wheel-rail forces according to any one of claims 1-7, and the method includes: S1: Equipment preparation. Based on the size and wheelbase of the train model, select the appropriate length of track roadbed module and install the 8 three-dimensional force sensors onto the sensor mounting base respectively. S2: Subgrade installation and leveling. On the floor of the wind tunnel test section, install the subgrade support brackets according to the design position, splice the subgrade on the brackets in sequence, and use a level to level the entire track surface to ensure that the levelness error is less than 0.1°. S3: Sensor integration. The sensor mount with the sensor is installed in the mounting groove of the roadbed. The four leveling screws on the bottom of the sensor mount ensure that the track lines on the upper surface of all sensor mounts are aligned and level. S4: Train model installation. Use hoisting equipment to place the train model smoothly on the roadbed, and use an optical positioning device to assist in placing each wheel on the second track of the corresponding sensor mounting base. Use special clamps and adhesives to fix the wheels to the second track, and check and ensure that the train model has no additional lateral tilt, pitch and roll. S5: System calibration. Static loading calibration is performed before the wind tunnel is started. Known standard loads are applied vertically, longitudinally, and laterally at the center of gravity of the train model. The outputs of each sensor are collected, and the calibration coefficient matrix is ​​calculated through data processing software. S6: Wind tunnel test and data acquisition. Start the wind tunnel and run it according to the set wind speed and wind direction angle conditions. The data acquisition system simultaneously collects the triaxial force signals from 8 sensors. S7: Data processing. After the test is completed, the data processing software uses the calibration coefficient matrix to correct the original data, synthesizes the six-part force dynamics of the whole vehicle in real time or post-processing, and directly outputs the wheel-rail force time history data of each measuring point.

9. The distributed measurement method for train aerodynamic forces and wheel-rail forces according to claim 8, characterized in that, The system calibration specifically includes: a. Static weights are applied longitudinally, laterally, and vertically to the roof and the front, middle, and rear sides of the model vehicle, respectively, and the static weight application includes at least three force levels; b. Collect sensor data under all loading conditions; c. Data processing: Import the data into specialized software, run the third-order multiple regression algorithm, and calculate the calibration coefficient matrix. d. Verify the calibration by applying a static load at another loading point and comparing the calibrated output value with the theoretical value to ensure that the verification error is less than 5%.

10. The distributed measurement method for train aerodynamic forces and wheel-rail forces according to claim 9, characterized in that, The data processing specifically includes: The overall aerodynamic force is synthesized by summing the longitudinal force components, vertical force components, and lateral force components measured by the eight sensors. The synthesis of overall aerodynamic moments, including calculation of roll moment and pitch moment. and Yaw moment; The wheel-rail force is obtained by taking the three-dimensional force output of each sensor as the three-dimensional wheel-rail force at the corresponding wheelset contact point.

Images