Railway track vibration isolation mat simulation testing device

Abstract

The utility model provides a track vibration isolation mat simulation detection device, including a plurality of elastic support components, lower basic simulation board, track board simulation board, vibration loading mechanism and vibration acceleration sensor, the vibration isolation mat sample of waiting for detecting is arranged between lower basic simulation board and track board simulation board, therefore can simulate actual vibration isolation mat floating plate track structure well, and the vibration isolation mat performance that detects obtains is very close to its performance in actual track, has very good reference value. Besides, through setting a plurality of elastic support components below lower basic simulation board, and setting vibration acceleration sensor on it, can take the vibration energy that vibration loading mechanism loads as input energy, take the elastic potential energy of elastic support component that vibration acceleration sensor detects as output energy, and evaluates the performance of vibration isolation mat based on input energy and output energy, compares with the traditional track lower basic vibration level difference method more intuitive and simple.

Description

Technical Field

[0001] This utility model belongs to the technical field of track component testing devices, specifically relating to a track vibration isolation pad simulation testing device. Background Technology

[0002] In floating slab track with vibration isolation pads, vibration isolation pads are installed between the sub-foundation and the track slab. These pads are made of elastic material. When a train passes over the track slab, the slab undergoes a certain degree of "elastic floating" due to the compression and deformation of the pads, thus reducing the transmission of vibration energy from the wheels rolling along the rails to the sub-foundation. To ensure better compatibility between the vibration isolation pads and specific track structures and achieve a more ideal vibration isolation effect, testing and optimization of the pads are necessary. Currently, the vibration level of the sub-foundation with and without vibration isolation pads is typically measured separately, and the vibration isolation effect of the pads is evaluated based on the difference between the two vibration levels. This testing method is inconvenient to operate, susceptible to external interference, and results in poor repeatability and reliability of the test results.

[0003] Testing vibration isolation pads in a laboratory setting would allow for more efficient testing, minimize external interference, and yield more reliable data. However, current laboratory testing methods only allow for parameters such as static stiffness; no testing device is currently available to effectively measure the vibration energy absorption characteristics of vibration isolation pads. Furthermore, to ensure the test data has significant reference value and can be used for optimizing vibration isolation pad products and track structures, the vibration energy absorption characteristics of the vibration isolation pads obtained in the laboratory need to closely approximate their performance in actual track structures. This also presents challenges for the design of testing equipment. Utility Model Content

[0004] This invention is designed to solve the aforementioned problems and aims to provide a simulation testing device that can conveniently test the energy absorption characteristics of vibration isolation pads in a laboratory environment. The invention employs the following technical solution:

[0005] This utility model provides a simulation testing device for track vibration isolation pads, used to test the energy absorption characteristics of vibration isolation pad samples. The device comprises: multiple elastic support components mounted on the ground; a lower foundation simulation plate mounted on the multiple elastic support components to simulate a lower foundation, with the vibration isolation pad sample placed on the upper surface of the lower foundation simulation plate; a track slab simulation plate mounted on the vibration isolation pad sample to simulate a track slab; one or more preloaded mass blocks mounted on the track slab simulation plate; an eccentric vibration motor mounted above the preloaded mass blocks to apply vibration energy to the vibration isolation pad sample; and one or more vibration acceleration sensors mounted on the lower foundation simulation plate to detect the vibration of the lower foundation simulation plate.

[0006] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the elastic support component is a spring, which is any one of a disc spring, a spiral steel spring, or a rubber spring; and there are multiple vibration acceleration sensors, which are disposed on the upper surface of the lower foundation simulation plate and respectively disposed directly above each of the disc springs.

[0007] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical feature: the stiffness of the multiple springs is the same, and the parallel stiffness of the multiple springs makes the natural frequency of the track vibration isolation pad simulation testing device higher than the excitation frequency of the eccentric vibration motor sweep frequency vibration.

[0008] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the excitation frequency is <100Hz, the total weight of the lower foundation simulation plate, the track slab simulation plate, and all the preloaded mass blocks is ≤470kg, the lower foundation simulation plate is a square concrete slab, and there are four springs, which are respectively set below the four corners of the lower foundation simulation plate, and the stiffness of each spring is the same and ≥46.5kN / mm.

[0009] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the excitation frequency is <100Hz, the total weight of the lower foundation simulation plate, the track slab simulation plate and all the preloaded mass blocks is ≤470kg, and there are three springs arranged in a triangle below the lower foundation simulation plate, with each spring having the same stiffness and ≥62kN / mm.

[0010] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical feature: the distance between two adjacent springs is 500mm.

[0011] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the eccentric vibration motor includes an eccentric block, the mass of the eccentric block is 0.3kg, and the eccentricity is ≤5mm.

[0012] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features, wherein the mass block limiting mechanism comprises multiple preloaded mass blocks, all of which are cylindrical and stacked sequentially. The mass block limiting mechanism includes: two auxiliary mounting plates, respectively disposed on the upper surface of the track slab simulation plate and on the uppermost preloaded mass block; and multiple limiting posts, the two ends of each limiting post being connected to the corresponding corners of the two auxiliary mounting plates, for limiting the stacked multiple preloaded mass blocks.

[0013] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the lower foundation simulation plate is a square concrete slab, and the track slab simulation plate is a square concrete slab.

[0014] The track vibration isolation pad simulation testing device provided by this utility model may also have the following technical features: the dimension of the track slab simulation plate in the surface direction is equal to the dimension of the vibration isolation pad sample in the surface direction and smaller than the dimension of the lower foundation simulation plate in the surface direction; the vibration isolation pad sample and the track slab simulation plate are stacked and disposed in the middle of the upper surface of the lower foundation simulation plate; and the vibration acceleration sensor is disposed on the upper surface of the lower foundation simulation plate and located at the corner or edge of the lower foundation simulation plate.

[0015] Functions and effects of utility models

[0016] The track vibration isolation pad simulation testing device provided by this utility model includes multiple elastic support components, a lower foundation simulation plate, a track slab simulation plate, a vibration loading mechanism, and a vibration acceleration sensor. The vibration isolation pad sample to be tested is placed between the lower foundation simulation plate and the track slab simulation plate, thus effectively simulating the actual vibration isolation pad floating slab track structure. The tested vibration isolation pad performance is very close to its performance in the actual track, providing valuable reference. Furthermore, by setting multiple elastic support components below the lower foundation simulation plate and placing a vibration acceleration sensor on them, the vibration energy loaded by the vibration loading mechanism can be used as the input energy, and the elastic potential energy of the elastic support components detected by the vibration acceleration sensor can be used as the output energy. The performance of the vibration isolation pad can be evaluated based on the input and output energy, which is more intuitive and simpler than the traditional track lower foundation vibration level difference method. Using this device, the vibration energy absorption characteristics of the vibration isolation pad can be accurately measured in a laboratory environment, avoiding the complexity and uncertainty of on-site testing, reducing external interference, and improving the repeatability and reliability of the test results. Attached Figure Description

[0017] Figure 1 This is a perspective view of the track vibration isolation pad simulation testing device in the embodiment of this utility model;

[0018] Figure 2 This is a side view of the track vibration isolation pad simulation testing device in an embodiment of this utility model;

[0019] Figure 3 This is a top view of a portion of the structure of the track vibration isolation pad simulation testing device in this embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the usage state of the track vibration isolation pad simulation testing device in an embodiment of this utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the floating plate track with vibration isolation pad in the existing technology.

[0022] Figure label:

[0023] Simulation testing device 11; elastic support component 112; lower foundation simulation plate 113; track slab simulation plate 114; preloading component 115; preloading mass block 1151; auxiliary mounting plate 1152; limiting column 1153; vibration loading mechanism 116; vibration acceleration sensor 117; data acquisition instrument 12; laptop computer 13; vibration isolation pad floating plate track 20B; lower foundation 21; strip groove 211; track slab 23; sleeper 24; rail 25; vibration isolation pad 22B; vibration isolation pad sample 22. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this utility model easy to understand, the following describes the track vibration isolation pad simulation testing device of this utility model in detail with reference to the embodiments and accompanying drawings.

[0025] <Example>

[0026] This embodiment provides a track vibration isolation pad simulation and testing device for simulating the actual track structure with floating vibration isolation pads and testing the vibration energy absorption characteristics of the vibration isolation pad sample. To facilitate the explanation of the correspondence between the device structure and the actual track structure, the structure of the floating vibration isolation pad track will be briefly described below.

[0027] Figure 5 This is a structural schematic diagram (sectional view) of the existing technology for vibration isolation pad floating plate track.

[0028] like Figure 5 As shown, the vibration isolation pad floating slab track 20B includes a lower foundation 21, vibration isolation pads 22B, track slab 23, sleepers 24, and rails 25.

[0029] The lower foundation 21 has a cross-section that is roughly "U" shaped, and a through strip groove 211 is formed in the middle of the lower foundation 21. The cross-section of the strip groove 211 is rectangular.

[0030] Vibration isolation pad 22B is a strip-shaped vibration isolation pad, the length direction of which is consistent with the extension direction of the track. Multiple vibration isolation pads 22B are arranged in two rows in the strip-shaped groove of the lower foundation 21.

[0031] The track plate 23 is a long strip plate with a rectangular cross-section and a cross-sectional size smaller than that of the strip groove 211. The track plate 23 is set above the vibration isolation pad 22B. The lower surface and two sides of the track plate 23 are in contact with the bottom of the strip groove 211 of the lower foundation 21 through multiple vibration isolation pads 22B. There are gaps between the two sides of the track plate 23 and the two side walls of the strip groove 211.

[0032] The sleeper 24 is a short sleeper. Multiple sleepers 24 are arranged on the upper surface of the track slab 23 and arranged in two rows along its length. Two rails 25 are respectively arranged on the two rows of sleepers 24.

[0033] That is, the track slab 23 does not directly contact the lower foundation 21, and vibration isolation pads 22B are set between the two to form strip support.

[0034] Figure 1 This is a perspective view of the track vibration isolation pad simulation testing device in this embodiment. Figure 2 This is a side view of the track vibration isolation pad simulation testing device in this embodiment.

[0035] like Figure 1 and Figure 2As shown, the track vibration isolation pad simulation testing device 11 is set on the ground 30, and includes multiple elastic support components 112, a lower foundation simulation plate 113, a track slab simulation plate 114, a preloading component 115, a vibration loading mechanism 116, and multiple vibration acceleration sensors 117.

[0036] The ground 30 is required to be solid, flat, and nearly rigid, with its upper surface being horizontal. For example, the ground 30 can be a concrete floor or a steel plate floor. Wooden flooring or other soft, elastic flooring should be avoided to prevent affecting the rigidity of the simulation testing device 11 above the ground 30.

[0037] Multiple elastic support components 112 are distributed on a horizontal surface and have a predetermined stiffness. The overall stiffness of the simulation detection device 11 can be adjusted (switched) by replacing elastic support components 112 with different stiffnesses. In this embodiment, all elastic support components 112 are disc springs with the same stiffness. In an alternative embodiment, other types of springs, such as helical steel springs or rubber springs, can also be used for the elastic support components 112.

[0038] The lower foundation simulation slab 113 is used to simulate the lower foundation in the track. It is a square concrete slab and can be made using the same materials and manufacturing process as the lower foundation in the actual track, so that it has essentially the same properties. In this embodiment, the lower foundation simulation slab 113 has dimensions of 700mm × 700mm × 90mm (length × width × height) and weighs approximately 122kg.

[0039] The track slab simulation plate 114 is used to simulate the track slab in the actual track. It is also a rectangular concrete slab and can be made using the same materials and manufacturing process as the actual track slab, so that it has essentially the same properties. In this embodiment, the track slab simulation plate 114 has dimensions of 325mm × 325mm × 90mm (length × width × height) and a weight of 26kg. It is located above the center of the lower foundation simulation plate 113. That is, the dimensions of the track slab simulation plate 114 in the facing direction are smaller than the dimensions of the lower foundation simulation plate 113 in the facing direction. The four edges of the upper surface of the lower foundation simulation plate 113 are not obstructed by the track slab simulation plate 114 in the vertical direction.

[0040] The vibration isolation pad sample 22 to be tested is placed between the lower foundation simulation plate 113 and the track plate simulation plate 114. Its dimensions in the surface direction are basically the same as those in the surface direction of the track plate simulation plate 114, so that the vibration and force loaded on the track plate simulation plate 114 can be applied to the sample more evenly.

[0041] In this embodiment, the vibration isolation pad sample 22 has a length × width of 325mm × 325mm and a thickness ≤ 60mm.

[0042] The preloading assembly 115 is used to preload a predetermined mass onto the vibration isolation pad sample 22 to better simulate the situation of a train passing over the vibration isolation pad. The preloading assembly 115 includes a limiting frame and multiple preloading mass blocks 1151, which are stacked on the track slab simulation plate 114. The limiting frame serves to limit the stacked preloading mass blocks 1151. By setting different numbers of preloading mass blocks 1151, different preloading requirements on the upper part of the vibration isolation pad sample 22 can be achieved.

[0043] In this embodiment, the preloaded mass blocks 1151 are flat cylindrical in shape and all have the same size. Each one has a diameter of 325mm, and the total weight of multiple preloaded mass blocks 1151 is approximately 322kg.

[0044] The limiting frame includes two square-shaped auxiliary mounting plates 1152, multiple cylindrical limiting posts 1153, and multiple fasteners (not shown in the figure). One auxiliary mounting plate 1152 is fixed to the center of the upper surface of the track slab simulation plate 114 by multiple fasteners. The other auxiliary mounting plate 1152 is positioned above the uppermost preloaded mass block 1151. The four corners of the two auxiliary mounting plates 1152 are respectively connected by four limiting posts 1153. The edges of the preloaded mass block 1151 are in approximately contact with the four limiting posts 1153, thereby being limited by them. In this embodiment, the dimensions of each auxiliary mounting plate 1152 are 325mm × 325mm × 5mm (length × width × height), and threaded hole components are welded to the four corners of each auxiliary mounting plate 1152, thus providing bolt mounting holes at the four corners.

[0045] The vibration loading mechanism 116 is installed on the preloading component 115 and is used to apply vibration energy to the preloading component 115, the track slab simulation plate 114, the vibration isolation pad sample 22 to be tested, and the lower foundation simulation plate 113 below it. Its working parameters can be set by the testing personnel.

[0046] In this embodiment, the vibration loading mechanism 116 is an eccentric vibration motor, wherein the eccentric block has a mass of 0.3 kg and an eccentricity of ≤5 mm. After multiple tests, it was found that when the eccentricity was greater than 5 mm, the eccentric force of the eccentric vibration motor was too large during the frequency sweep excitation process, which caused problems such as shaking and positional displacement of the eccentric vibration motor. Therefore, the eccentricity was set to be less than or equal to 5 mm.

[0047] Figure 3 This is a top view of part of the track vibration isolation pad simulation testing device in this embodiment.

[0048] like Figures 1 to 3As shown, multiple vibration acceleration sensors 117 are respectively disposed on the upper surface of the lower foundation simulation plate 113 and respectively disposed directly above each elastic support component 112 (disc spring), for detecting the vibration generated by the lower foundation simulation plate 113 during the frequency sweep excitation process of the eccentric vibration motor.

[0049] The purpose of setting multiple elastic support components 112 is to adjust the stiffness of the entire simulation detection device 11 system, thereby adjusting the natural frequency of the entire device system so that the natural frequency of the device system can always be higher than the excitation frequency of the eccentric vibration motor sweep frequency vibration, thereby eliminating the influence of the device system itself on the detection results.

[0050] In this embodiment, the excitation frequency of the eccentric vibration motor sweep vibration is 1Hz to 100Hz. This range is consistent with the existing range for evaluating the impact of track vibration on the human body.

[0051] Considering multiple disc springs and the upper mass above them as a mass-spring system, the natural frequency of this system can be calculated using the following formula:

[0052]

[0053] In the formula, k0 is the system stiffness, which is the parallel stiffness of multiple disc springs; m is the mass of the upper mass body.

[0054] In this embodiment, the mass of the upper mass body is only considered (the relative mass of the vibration isolation pads to be tested is very light and can be ignored), the lower foundation simulation plate 113, track slab simulation plate 114, and multiple preloaded mass blocks 1151, with a maximum mass m of approximately 470 kg.

[0055] Four elastic support components 112 (disc springs) are respectively installed at the four corners of the lower foundation simulation plate 113, that is, the four disc springs are arranged at the four corner points of a square, and the distance between two adjacent disc springs is 500mm. The stiffness of each disc spring is ≥46.5kN / mm. The minimum parallel stiffness of the four disc springs is k=46.5×4=186kN / mm. The system's natural frequency is minimized when the stiffness of the disc springs is at its minimum value.

[0056]

[0057] Therefore, by setting up multiple disc springs, the natural frequency of the simulation detection device 11 system itself can always be higher than the excitation frequency of the eccentric vibration motor sweep frequency vibration.

[0058] In an alternative solution, multiple disc springs of other quantities and corresponding distributions can also be used. For example, three disc springs can be used, distributed below the lower foundation simulation plate 113, and arranged at the three corner points of an equilateral triangle. The stiffness of the three disc springs is the same and ≥62kN / mm, which can achieve a similar effect.

[0059] The components can be assembled according to the following steps to form the above-mentioned track vibration isolation pad simulation testing device 11:

[0060] Step 1: Select a suitable testing site, ensuring that the ground is firm, flat, and approximately rigid. Arrange the four elastic support components 112 (disc springs) in a square with a spacing of 500mm.

[0061] Step 2: Place the lower foundation simulation plate 113 on the multiple elastic support components 112, and ensure that the plane center of the lower foundation simulation plate 113 coincides with the intersection center of the four elastic support components 112.

[0062] Step 3: Place the vibration isolation pad sample 22 on the lower foundation simulation plate 113, and ensure that the center of the plane of the vibration isolation pad sample 22 coincides with the center of the plane of the lower foundation simulation plate 113.

[0063] Step 4: Place the track slab simulation plate 114 on the vibration isolation pad sample 22, and ensure that the center of the plane of the track slab simulation plate 114 coincides with the center of the plane of the vibration isolation pad sample 22.

[0064] Step 5: Place an auxiliary mounting plate 1152 on the track slab simulation plate 114.

[0065] Step 6: Place a selected number of preloaded mass blocks 1151 on the auxiliary mounting plate 1152.

[0066] Step 7: Place another auxiliary mounting plate 1152 on the topmost preloaded mass block 1151 and install multiple limiting posts 1153. Fix the two auxiliary mounting plates 1152 and the multiple limiting posts 1153 with fasteners.

[0067] Step 8: Place the vibration loading mechanism 116 on the upper auxiliary mounting plate 1152 and fix it with fasteners (welding bolts).

[0068] Step 9: Vibration acceleration sensors 117 are arranged on the upper surface of the four corners of the lower base simulation plate 113, and are positioned directly above the four elastic support components 112 (disc springs).

[0069] After assembly, the vibration acceleration sensor 117 can be debugged, and then the eccentric vibration motor can be started to apply vibration energy and collect data.

[0070] The track vibration isolation pad simulation testing device 11 described above can effectively simulate the actual track structure of the vibration isolation pad floating plate, thereby testing the vibration energy absorption characteristics of the vibration isolation pad sample 22.

[0071] The vibration energy applied by the eccentric vibration motor is transferred to the vibration isolation pad sample 22 via the preload component 115 and the track slab simulation plate 114. After being dissipated and absorbed by the vibration isolation pad sample 22, it is transferred to the lower foundation simulation plate 113. Multiple vibration acceleration sensors 117 installed on the lower foundation simulation plate 113 detect the vibration acceleration data of the lower foundation simulation plate 113 after the vibration energy is absorbed by the vibration isolation pad sample 22. Since the parameters of the eccentric vibration motor are known, the vibration energy applied by the eccentric vibration motor to the device system can be easily calculated based on its parameters as the input energy. Based on the measured vibration acceleration data, the corresponding vibration energy (elastic potential energy of multiple elastic support components 112) can be calculated as the output energy. Then, the vibration energy absorption performance of the vibration isolation pad sample 22 can be evaluated intuitively and conveniently based on the input energy and output energy.

[0072] Figure 4 This is a schematic diagram of the track vibration isolation pad simulation testing device in use in this embodiment.

[0073] like Figure 4 As shown, during use, multiple vibration acceleration sensors 117 can be connected to the data acquisition instrument 13 via corresponding cables. The data acquisition instrument 13 is then connected to the laptop 14, thereby transmitting the vibration acceleration data to the laptop 14 in real time for calculation and analysis, and obtaining the energy absorption characteristic data of the vibration isolation pad sample 22.

[0074] The role and effect of the embodiments

[0075] The track vibration isolation pad simulation testing device provided in this embodiment includes multiple elastic support components, a lower foundation simulation plate, a track slab simulation plate, a vibration loading mechanism, and a vibration acceleration sensor. The vibration isolation pad sample to be tested is placed between the lower foundation simulation plate and the track slab simulation plate, thus effectively simulating the actual vibration isolation pad floating slab track structure. The tested vibration isolation pad performance is very close to its performance in the actual track, providing valuable reference. Furthermore, by setting multiple elastic support components below the lower foundation simulation plate and placing vibration acceleration sensors on them, the vibration energy loaded by the vibration loading mechanism can be used as the input energy, and the elastic potential energy of the elastic support components detected by the vibration acceleration sensors can be used as the output energy. The performance of the vibration isolation pad can be evaluated based on the input and output energy, which is more intuitive and simpler than the traditional track lower foundation vibration level difference method. Using this device, the vibration energy absorption characteristics of the vibration isolation pad can be accurately measured in a laboratory environment, avoiding the complexity and uncertainty of on-site testing, reducing external interference, and improving the repeatability and reliability of the test results.

[0076] In this embodiment, the vibration loading mechanism is an eccentric vibration motor, capable of sweeping vibration excitation from 1Hz to 100Hz. The parallel stiffness of multiple disc springs ensures that the natural frequency of the device system is always higher than the excitation frequency of the eccentric vibration motor's sweeping vibration, thus eliminating the influence of the simulation detection device itself on the detection results and obtaining more accurate and reliable results. Furthermore, by setting the eccentric vibration motor, different excitation conditions can be easily simulated, offering high flexibility in use.

[0077] Furthermore, the testing equipment also includes multiple preloaded mass blocks. By setting different numbers of preloaded mass blocks above the track slab simulation plate, it can easily adapt to different preload requirements, making it highly flexible in use.

[0078] Furthermore, a limiting frame is also provided to limit the movement of multiple preloaded mass blocks, which can prevent the multiple preloaded mass blocks that are stacked together from shifting or shaking due to high-frequency vibration during the detection process, thus affecting the detection results and detection efficiency.

[0079] The above embodiments are merely illustrative of specific implementations of this utility model, and the utility model is not limited to the scope of the above embodiments. Those skilled in the art should understand that the utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are only for illustrating the principles of the utility model. Various changes and modifications can be made to the utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the utility model as claimed. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A simulation testing device for track vibration isolation pads, used to test the energy absorption characteristics of vibration isolation pad samples, characterized in that, include: Multiple flexible support components are installed on the ground; A lower foundation simulation plate is set on multiple elastic support components to simulate the lower foundation, and the vibration isolation pad sample is placed on the upper surface of the lower foundation simulation plate; A track slab simulation plate is placed on the vibration isolation pad sample to simulate a track slab; One or more preloaded mass blocks are set on the track slab simulation plate; An eccentric vibration motor is positioned above the preloaded mass block to apply vibration energy to the vibration isolation pad sample. as well as One or more vibration acceleration sensors are mounted on the lower foundation simulation plate to detect the vibration of the lower foundation simulation plate.

2. The track vibration isolation pad simulation testing device according to claim 1, characterized in that: in, The elastic support component is a spring. The spring is any one of a disc spring, a helical steel spring, or a rubber spring. Multiple vibration acceleration sensors are disposed on the upper surface of the lower foundation simulation plate, and are respectively disposed directly above each of the springs.

3. The track vibration isolation pad simulation testing device according to claim 2, characterized in that: in, All of the springs have the same stiffness. The parallel stiffness of the multiple springs causes the natural frequency of the track vibration isolation pad simulation detection device to be higher than the excitation frequency of the sweep frequency vibration of the eccentric vibration motor.

4. The track vibration isolation pad simulation testing device according to claim 3, characterized in that: in, The excitation frequency is <100Hz. The total weight of the lower foundation simulation slab, the track slab simulation slab, and all the preloaded mass blocks is ≤470kg. The lower foundation simulated slab is a square concrete slab. There are four springs, which are respectively set at the four corners of the lower base simulation plate. Each spring has the same stiffness and is ≥46.5kN / mm.

5. The track vibration isolation pad simulation testing device according to claim 3, characterized in that: in, The excitation frequency is <100Hz. The total weight of the lower foundation simulation slab, the track slab simulation slab, and all the preloaded mass blocks is ≤470kg. There are three springs arranged in a triangle below the lower foundation simulation plate, and each spring has the same stiffness of ≥62kN / mm.

6. The track vibration isolation pad simulation testing device according to any one of claims 3-5, characterized in that: in, The distance between two adjacent springs is 500mm.

7. The track vibration isolation pad simulation testing device according to claim 1, characterized in that: in, The eccentric vibration motor includes an eccentric block. The mass of the eccentric block is 0.3 kg, and the eccentricity is ≤ 5 mm.

8. The track vibration isolation pad simulation testing device according to claim 1, characterized in that, Also includes: Mass block limiting mechanism. The preloaded mass blocks are multiple, all cylindrical, and stacked sequentially. The mass block limiting mechanism includes: Two auxiliary mounting plates are respectively mounted on the upper surface of the track slab simulation plate and on the topmost preloaded mass block; and Multiple limiting posts, each with its two ends connected to the corners of the two auxiliary mounting plates, are used to limit the movement of the multiple preloaded mass blocks stacked together.

9. The track vibration isolation pad simulation testing device according to claim 1, characterized in that: in, The lower foundation simulation slab is a square concrete slab. The simulated track slab is a square concrete slab.

10. The track vibration isolation pad simulation testing device according to claim 9, characterized in that: in, The dimension of the simulated track slab in the surface direction is equal to the dimension of the vibration isolation pad sample in the surface direction, and smaller than the dimension of the simulated lower foundation slab in the surface direction. The vibration isolation pad sample and the track slab simulation plate are stacked and disposed in the middle of the upper surface of the lower foundation simulation plate. The vibration acceleration sensor is disposed on the upper surface of the lower foundation simulation plate and is located at a corner or edge of the lower foundation simulation plate.

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