Highway tunnel lining load loading device and test method

Abstract

The invention belongs to the technical field of tunnel engineering, and discloses a highway tunnel lining load loading device and a test method.The device comprises a base and a reaction frame arranged on the base, a lining model is arranged in the reaction frame, the device further comprises a load loading system, and the load loading system is connected with the lining model through the reaction frame; the load measuring system comprises a strain gauge arranged on the lining model and a displacement meter arranged in the lining model, and the strain gauge is connected with the load loading system; the pressure sensor is arranged on the load loading system; the DIC equipment and the strain acquisition instrument are arranged in the lining model; the strain acquisition instrument is electrically connected with the strain gauge and the displacement meter; the air bag is arranged on the outer side of the lining model, the load loading system abuts against the air bag, and the air bag communicates with a plurality of valves; switching between point loading and surface loading is realized by opening or closing the valve in the experiment process; the problem that point loading and surface loading cannot be converted in the prior art is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel engineering, and specifically relates to a highway tunnel lining load loading device and a test method. Background Art

[0002] As of the end of 2022, my country has 24,850 highway tunnels in operation, with a total mileage of 26,784.3 km. As my country's highway mileage continues to increase, a large number of tunnels have suffered from various degrees of damage, such as cracking, water leakage, and falling blocks. Domestic and foreign scholars have conducted a lot of research on lining structures. In the research, the commonly used simulation method is the scaled model test. The scaled model test is a representative object copied according to the similar relationship of the real structure, and has all and part of the characteristics of the actual structure. Compared with the full-scale test, the scaled model can be used to study large structures at a smaller scale. At the same time, the scaled model is relatively easy to make, easy to disassemble, saves materials, labor and time, and saves research costs.

[0003] Referring to the existing patent publication (announcement) number CN112595533A, a shield tunnel stratum action simulation test device and its test method, the device uses a servo hydraulic system to control the hydraulic jack to provide a constant pressure for the test, which can simulate the tunnel operation. For another example, referring to the existing patent publication (announcement) number CN114720289A, a deep buried tunnel simulation test section load loading device and test method, the device simulates the surrounding rock pressure acting on the lining in actual working conditions through a rubber bag and a tunnel lining model, avoiding the load (such as a jack) directly acting on the lining part, and ignoring the complete contact between the surrounding rock and the lining.

[0004] In the tunnel lining load test, the jack is used to directly act on the local lining, usually to simulate specific load conditions. For example, in the actual tunnel lining, the lining will be subjected to concentrated forces, such as local pressure caused by external impact. Using jacks for point loading can simulate such actual working conditions. However, in the actual tunnel lining, it will be subjected to uniform pressure from the surrounding rock. Uniform loading of the entire lining surface through rubber bags can simulate uniform loads.

[0005] In the tunnel lining load test, it is very necessary to perform both point loading and surface loading. If only point loading or surface loading is performed, this single loading method cannot fully simulate the type of load that the actual tunnel lining is subjected to. In practice, the lining may be subjected to concentrated loads and uniform loads simultaneously or separately. In addition, a single loading method cannot provide enough experimental data to fully verify and calibrate the calculation model and numerical simulation, affecting the accuracy of the test data. Summary of the invention

[0006] The purpose of this scheme is to provide a highway tunnel lining load loading device to solve the problem of how to convert point loading and surface loading.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a highway tunnel lining load loading device, comprising a base and a reaction frame arranged on the base, wherein a lining model is arranged in the reaction frame, and further comprising: A load loading system, wherein the load loading system is connected to the lining model via a reaction frame; A load measurement system, the load measurement system includes a strain gauge arranged on the lining model and a displacement meter arranged in the lining model, the strain gauge is connected to the load loading system; it also includes a pressure sensor arranged on the load loading system and a DIC device and a strain acquisition instrument arranged in the lining model, the strain acquisition instrument is electrically connected to the strain gauge and the displacement meter; it also includes an air bag arranged outside the lining model, the load loading system is in conflict with the air bag, a plurality of valves are connected in the air bag, and the air bag is connected to an air pump through a pipeline; A load control system, wherein the load control system comprises a servo system and a PLC system for controlling a load loading system, wherein the PLC system is electrically connected to a pressure sensor.

[0008] The principle of this scheme is as follows: (1) The lining is loaded by the load loading system, and the data collected by the displacement meter and strain gauge are transmitted to the strain acquisition instrument. The pressure sensor detects the load and transmits the data to the PLC system. The servo system is controlled by the PLC to control the loading amount of the load loading system. The DIC device analyzes the image sequence of the lining model surface to obtain the displacement and deformation data of the lining surface. (2) When it is necessary to load the lining model at a single point, open the valve and control the load loading system to pressurize the airbag. The gas in the pressurized area of ​​the airbag will be filled into the unpressurized airbag. At this time, the load directly acts on the pressurized lining model, thereby performing point loading on the lining. (3) When it is necessary to load the surface of the lining model, open the valve again to allow the gas to flow back and fill the entire airbag with gas. Then the load loading system pressurizes the airbag and disperses the load through the airbag so that it acts on the entire lining model, thereby performing surface loading on the lining. (4) During a single test, the valve can be opened or closed regularly to switch between point loading and surface loading of the lining.

[0009] The effects of this scheme are as follows: (1) The load amount of the load loading system is controlled by the servo system, which can meet the requirements of load application of different sizes and speeds. The load amount of the load loading system is read by the pressure sensor and transmitted to the PLC system to achieve different graded loads and different loading rates. (2) The load measurement system uses strain gauges and displacement meters, and is equipped with DIC equipment. The data of the two can be verified with each other to ensure the accuracy of the test data and provide basic data for multi-dimensional analysis of test data. (3) By performing point loading and surface loading on the lining model, various load conditions that the tunnel lining may encounter in actual use can be simulated, including local concentrated loads and overall uniform loads. (4) By converting point loading and surface loading during the experiment, the data of the lining under different loading modes can be obtained. The two types of data can be obtained at the same time, and the two types of data can be verified and compared. (5) Performing two types of loading tests on the same lining model at the same time can reduce the construction cost of the lining model and improve the test efficiency.

[0010] Furthermore, the reaction frame includes an arc-shaped support plate, on which a plurality of sleeves are arranged; the load-applying system includes a hydraulic jack arranged in the sleeve, one end of the hydraulic jack is in contact with the strain gauge, and the pressure sensor is arranged on the hydraulic jack; a bracket is provided on the base, and the DIC device and the strain collector are arranged on the bracket.

[0011] The principle and effect of this scheme are: in view of the current scale model, which mostly uses backfill, and then applies load with hydraulic jack to simulate the relationship between surrounding rock and lining. This device uses a curved steel plate similar to the contour of the tunnel lining, and cooperates with rubber pads to simulate the close relationship between surrounding rock and lining. Furthermore, the load measurement system also includes a spring arranged on the base.

[0012] The principle and effect of this scheme are: the spring is used to simulate the spring resistance coefficient of the surrounding rock. By changing the wire diameter and outer diameter of the spring, the elastic resistance coefficient of the surrounding rock of different levels can be simulated, which can more realistically reflect the relationship between the surrounding rock and the lining.

[0013] Furthermore, the number of the valves is equal to the number of the hydraulic jacks.

[0014] The principle and effect of this solution are: the number of valves and hydraulic jacks is matched to achieve multi-point loading and surface loading.

[0015] Furthermore, a carrier plate is provided on the bracket, the DIC device is provided on the carrier plate, a solenoid valve is provided on the carrier plate, the solenoid valve is connected to the airbag through a pipeline, an exhaust valve is provided on the pipeline, the solenoid valve is electrically connected to the PLC system, and there are three solenoid valves, which are respectively provided on the upper side and left and right sides of the carrier plate.

[0016] The principle and effect of this scheme are as follows: (1) Since the DIC device must be installed in the lining model to monitor the changes of the cracks in the lining model, when the lining model is cracked and broken, it will produce debris, which is easy to hit the DIC device and damage the internal optical components. However, it is not possible to install protective equipment such as transparent glass plates in front of the DIC device, which will not only affect the image quality of the DIC device capturing the crack deformation, but also cause light refraction and image distortion. (2) When the PLC system detects that the values ​​of the pressure sensor and the strain gauge exceed the threshold, it controls the exhaust valve to open so that the airbag is connected to the solenoid valve. When the DIC device detects that a gap has occurred in the lining, the PLC system controls the solenoid valve to open to eject gas, thereby pushing the carrier to drive the DIC device to move away from the lining where the gap occurs. (3) The solenoid valves are respectively arranged on the upper side, left side and right side of the carrier, so that the outlet ends of the three solenoid valves are respectively facing the lining of the pressure section. When a crack occurs in any section of the lining, the corresponding solenoid valve opens, so that the carrier drives the DIC device to move in the opposite direction, thereby moving away from the lining where the crack occurs.

[0017] Furthermore, a slide groove is provided on the bracket, a pulley is provided at the bottom of the carrier plate, and the pulley is slidably arranged in the slide groove.

[0018] The principle and effect of this solution are that the slide groove and the pulley provide positioning and guiding functions for the movement of the carrier plate.

[0019] A highway tunnel lining load test method includes applying a highway tunnel lining load loading device as described above, and includes the following steps: Step S10: Calculate similar material parameters according to similarity theory, and cast tunnel lining components and cubic test blocks; Step S20: Calculate the spring stiffness and size according to the elastic resistance coefficient of the surrounding rock, configure the number, outer diameter and wire diameter of the corresponding springs, and calculate the load applied at each level in the scaled model; Step S30: Performing a cubic compressive strength test on the cubic test blocks and lining models that have reached the curing age. After the strength requirements are met, the lining models are transported to the reaction frame, and then the jacks are assembled, the displacement meters are placed, the strain gauges are pasted, and the DIC equipment is set up and debugged; Step S40: Select the lining loading area according to the test content, control the load, loading time and holding time applied at each level through the PLC system and servo system, and control the loading accuracy to perform single-point or multi-point loading; Step S50: monitor the strain of key control points and each point of the lining by using strain gauges and DIC equipment, and monitor the displacement of the control points of the lining structure by using displacement meters; Step S60: Feedback the load to the computer terminal through the PLC system, synchronously transmit the displacement meter data and the strain gauge data to the computer terminal through the strain acquisition instrument, and the DIC device records the entire lining crack evolution process and strain conditions; Step S70: Process the test data to form valid test data.

[0020] Furthermore, in step S40, point loading or surface loading may be selected, and the specific steps are as follows: Step S41: installing an air bag on the outside of the lining model and the inside of the strain gauge, and filling the air bag with high-pressure gas; Step S42: when point loading is selected, the valve is opened to connect the two ends of the valve and the airbag, and the hydraulic jack is started through the PLC system and the servo system to perform point loading on the lining model to form point loading test data; Step S43: When surface loading is selected, the valve is closed, and the hydraulic jack is started through the PLC system and the servo system to perform surface loading on the lining model to form surface loading test data; Step S44: When point-surface alternating loading is selected, the valve can be opened or closed regularly during the experiment, and the hydraulic jack can be started through the PLC system and the servo system to perform point-surface alternating loading on the lining model to form point-surface loading test data; Step S45: Compare and analyze the point loading test data, the surface loading test data, and the point-surface alternating loading test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a highway tunnel lining load loading device according to the present invention Figure 1 ; Figure 2 A schematic diagram of a highway tunnel lining load loading device according to the present invention Figure 2 ; Figure 3 The present invention is a flow chart of a highway tunnel lining load test method.

[0022] The figure marks in the drawings of the specification include: base 1, reaction frame 2, arc support plate 21, sleeve 22, lining model 3, load applying system 4, load measuring system 5, strain gauge 51, displacement meter 52, pressure sensor 53, airbag 54, valve 55, spring 56, bracket 6, carrier plate 7, and solenoid valve 8. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the concept and technical effects of the present invention in combination with the embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention: Example: See also Figure 1 A highway tunnel lining load loading device includes a base 1, a reaction frame 2 is arranged on the base 1, the reaction frame 2 includes an arc-shaped support plate 21 and a sleeve 22, the sleeve 22 is a plurality of sleeves 22 evenly distributed along the arc-shaped support plate, and a lining model 3 is arranged in the reaction frame 2.

[0024] A load loading system 4 and a load measuring system 5 are also provided in the reaction frame 2 . The load loading system 4 uses a hydraulic jack. The number of the hydraulic jacks is set to be multiple and is arranged in the sleeve 22 . The load measurement system 5 includes a strain gauge 51 arranged on the lining model 3 and a displacement meter 52 arranged on the inner side of the lining model 3. The number of the strain gauges 51 and the displacement meter 52 is equal to the number of the hydraulic jacks. One side of the strain gauge 51 is in contact with the hydraulic jack, and the displacement meter 52 is arranged at a relative position to the strain gauge 51. The load measurement system 5 also includes a pressure sensor 53 and a DIC device and a strain collector arranged in the lining model 3. The number of the pressure sensors 53 corresponds to the number of the hydraulic jacks, and the pressure sensor 53 is arranged on the hydraulic jack. A bracket 6 is provided on the base 1. The DIC device and the strain collector are both arranged on the bracket 6. The strain collector is electrically connected to the strain gauge 51 and the displacement meter 52. The load measurement system 5 also includes a spring 56 arranged on the base 1. The spring 56 is used to simulate the spring resistance coefficient of the surrounding rock. By changing the wire diameter and outer diameter of the spring 56, the elastic resistance coefficient of the surrounding rock of different levels can be measured, which can more realistically reflect the relationship between the surrounding rock and the lining.

[0025] It also includes a load control system, which includes a servo system and a PLC system for controlling the oil intake of the hydraulic jack. The PLC system is electrically connected to the pressure sensor 53.

[0026] Specific working principle: The lining model 3 is loaded by the hydraulic jack, the data collected by the displacement meter 52 and the strain gauge 51 are transmitted to the strain acquisition instrument, the pressure sensor 53 detects the load and transmits the data to the PLC system, and the servo system is controlled by the PLC to control the loading amount of the hydraulic jack. The DIC device analyzes the image sequence of the surface of the lining model 3 to obtain the displacement and deformation data of the surface of the lining model 3.

[0027] See also Figure 2The load measurement system 5 also includes an air bag 54 arranged outside the lining model 3, the hydraulic jack is in conflict with the air bag 54, and valves 55 are arranged in the air bag 54. The number of valves 55 is equal to that of the hydraulic jacks, thereby dividing the air bag 54 into multiple compartments. The air bag 54 is connected to an air pump through a pipeline.

[0028] Specific working principle: When it is necessary to load the lining model 3 at a single point, open the valve 55, control the load loading system 4 to pressurize the airbag 54, and the gas in the pressurized area of ​​the airbag 54 will be filled into the unpressurized airbag 54. At this time, the load acts directly on the pressurized lining model 3, thereby performing point loading on the lining. When it is necessary to load the surface of the lining model 3, open the valve 55 again to allow the gas to flow back, so that the entire airbag 54 is filled with gas, and then the load loading system 4 pressurizes the airbag 54, and disperses the load through the airbag 54, so that it acts on the entire lining model 3, thereby performing surface loading on the lining. During a single test, the valve can be opened or closed regularly to switch between point loading and surface loading of the lining.

[0029] Since the DIC device must be installed in the lining model 3 to monitor the changes of the cracks in the lining model 3, when the lining model 3 is cracked and broken, it will produce debris, which is easy to hit the DIC device and damage the internal optical components. However, it is also impossible to set protective equipment such as transparent glass plates in front of the DIC device, which will not only affect the image quality of the DIC device capturing the crack deformation, but also cause light refraction, resulting in image distortion. Therefore, a carrier plate 7 is provided on the bracket 6, the DIC device is provided on the carrier plate 7, a slide groove is provided on the bracket 6, a pulley is provided at the bottom of the carrier plate 7, and the pulley is slidably arranged in the slide groove; a solenoid valve 8 is provided on the carrier plate 7, the solenoid valve 8 is connected to the airbag 54 through a pipeline, and an exhaust valve is provided on the pipeline. The exhaust valve and the solenoid valve 8 are both electrically connected to the PLC system. There are three solenoid valves 8, which are respectively arranged on the upper side and left and right sides of the carrier plate 7.

[0030] When the PLC system detects that the values ​​of the pressure sensor 53 and the strain gauge 51 exceed the threshold, the exhaust valve is controlled to open, so that the airbag 54 is connected to the electromagnetic valve 8. When the DIC device detects that a gap has occurred in the lining, the electromagnetic valve 8 is controlled to open through the PLC system to eject gas, thereby pushing the carrier plate 7 to drive the DIC device to move away from the lining position where the gap has occurred. The electromagnetic valves 8 are respectively arranged on the upper side, left side and right side of the carrier plate 7, so that the outlet ends of the three electromagnetic valves 8 are respectively facing the lining of the pressure section. When cracks occur in any section of the lining, the corresponding electromagnetic valve 8 is opened, so that the carrier plate 7 drives the DIC device to move in the opposite direction, thereby moving away from the lining where the crack has occurred.

[0031] In order to better implement the above-mentioned load loading device, the present invention also provides a highway tunnel lining load loading test method, including application of a highway tunnel lining load loading device, including the following steps: Step S10: Calculate similar material parameters according to similarity theory, and cast tunnel lining components and cubic test blocks; Step S20: Calculate the spring stiffness and size according to the elastic resistance coefficient of the surrounding rock, and configure the number, outer diameter and wire diameter of the corresponding spring 56 to calculate the load applied at each level in the scaled model; Step S30: Performing a cubic compressive strength test on the cubic test block and the lining model 3 that have reached the curing age. After the strength requirements are met, the lining model 3 is transported to the reaction frame 2, and then the hydraulic jack is assembled, the displacement meter 52 is placed, the strain gauge 51 is pasted, and the DIC equipment is set up and debugged; Step S40: Select the lining loading area according to the test content, control the load, loading time and holding time applied at each level through the PLC system and servo system, and control the loading accuracy to perform single-point or multi-point loading; Step S50: monitor the strain of key control points and each point of the lining through the strain gauge 51 and the DIC device, and monitor the displacement of the lining structure control point through the displacement meter 52; Step S60: Feedback the load to the computer terminal through the PLC system, and synchronously transmit the displacement meter 52 data and the strain gauge 51 data to the computer terminal through the strain acquisition instrument, and the DIC device records the entire lining crack evolution process and strain conditions; Step S70: Process the test data to form valid test data.

[0032] Further, in step S40, point loading or surface loading may be selected, and the specific steps are as follows: Step S41: installing an air bag 54 on the outside of the lining model 3 and the inside of the strain gauge 51, and filling the air bag 54 with high pressure gas through an air pump; Step S42: when point loading is selected, the valve 55 is opened to connect the two ends of the valve 55 and the airbag 54, and the hydraulic jack is started through the PLC system and the servo system to perform point loading on the lining model 3 to form point loading test data; Step S43: When surface loading is selected, the valve 55 is closed, and the hydraulic jack is started through the PLC system and the servo system to perform surface loading on the lining model to form surface loading test data; Step S44: when point-surface alternating loading is selected, the valve can be opened or closed regularly during the experiment, and the hydraulic jack can be started through the PLC system and the servo system to perform point-surface alternating loading on the lining model 3 to form point-surface loading test data; Step S45: Compare and analyze the point loading test data, the surface loading test data, and the point-surface alternating loading test data.

[0033] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A highway tunnel lining load loading device, comprising a base (1) and a reaction frame (2) arranged on the base (1), wherein a lining model (3) is arranged in the reaction frame (2), characterized in that: Also includes: A load loading system (4), wherein the load loading system (4) is connected to the lining model (3) via a reaction frame (2); A load measurement system (5), the load measurement system (5) comprising a strain gauge (51) provided on a lining model (3) and a displacement meter (52) provided in the lining model (3), the strain gauge (51) being connected to a load loading system (4); further comprising a pressure sensor (53) provided on the load loading system (4) and a DIC device and a strain acquisition instrument provided in the lining model (3), the strain acquisition instrument being electrically connected to the strain gauge (51) and the displacement meter (52); further comprising an air bag (54) provided outside the lining model (3), the load loading system (4) being in contact with the air bag (54), a plurality of valves (55) being connected in the air bag (54), and the air bag (54) being connected to an air pump via a pipeline; A load control system, the load control system comprising a servo system and a PLC system for controlling a load loading system (4), the PLC system being electrically connected to a pressure sensor (53).

2. A highway tunnel lining load loading device according to claim 1, characterized in that: The reaction frame (2) comprises an arc-shaped support plate (21), and a plurality of sleeves (22) are arranged on the arc-shaped support plate (21); the load-applying system (4) comprises a hydraulic jack arranged in the sleeve (22), one end of the hydraulic jack abuts against the strain gauge (51), and the pressure sensor (53) is arranged on the hydraulic jack; a bracket (6) is arranged on the base (1), and the DIC device and the strain acquisition instrument are arranged on the bracket (6).

3. A highway tunnel lining load loading device according to claim 1, characterized in that: The load measurement system (5) also includes a spring (56) arranged on the base (1).

4. A highway tunnel lining load loading device according to claim 1, characterized in that: The number of the valves (55) is equal to the number of the hydraulic jacks.

5. A highway tunnel lining load loading device according to claim 2, characterized in that: The bracket (6) is provided with a carrier plate (7), the DIC device is provided on the carrier plate (7), the carrier plate (7) is provided with a solenoid valve (8), the solenoid valve (8) is connected to the air bag (54) through a pipeline, the pipeline is provided with an exhaust valve, the exhaust valve and the solenoid valve (8) are both electrically connected to the PLC system, and the number of the solenoid valves (8) is three, and they are respectively provided on the upper side and left and right sides of the carrier plate (7).

6. A highway tunnel lining load loading device according to claim 5, characterized in that: The bracket (6) is provided with a slide groove, and the bottom of the carrier plate (7) is provided with a pulley, and the pulley is slidably arranged in the slide groove.

7. A highway tunnel lining load test method, comprising applying a highway tunnel lining load loading device as claimed in any one of claims 1 to 6, characterized in that: The steps include: Step S10: Calculate similar material parameters according to similarity theory, and cast tunnel lining components and cubic test blocks; Step S20: Calculate the spring stiffness and size according to the elastic resistance coefficient of the surrounding rock, configure the number, outer diameter and wire diameter of the corresponding springs, and calculate the load applied at each level in the scaled model; Step S30: Performing a cubic compressive strength test on the cubic test blocks and lining models that have reached the curing age. After the strength requirements are met, the lining models are transported to the reaction frame, and then the jacks are assembled, the displacement meters are placed, the strain gauges are pasted, and the DIC equipment is set up and debugged; Step S40: Select the lining loading area according to the test content, control the load, loading time and holding time applied at each level through the PLC system and servo system, and control the loading accuracy to perform single-point or multi-point loading; Step S50: monitor the strain of key control points and each point of the lining by using strain gauges and DIC equipment, and monitor the displacement of the control points of the lining structure by using displacement meters; Step S60: Feedback the load to the computer terminal through the PLC system, synchronously transmit the displacement meter data and the strain gauge data to the computer terminal through the strain acquisition instrument, and the DIC device records the entire lining crack evolution process and strain conditions; Step S70: Process the test data to form valid test data.

8. A highway tunnel lining load test method according to claim 7, characterized in that: In step S40, point loading or surface loading can be selected, and the specific steps are as follows: Step S41: installing an air bag on the outside of the lining model and the inside of the strain gauge, and filling the air bag with high-pressure gas through an air pump; Step S42: when point loading is selected, the valve is opened to connect the two ends of the valve and the airbag, and the hydraulic jack is started through the PLC system and the servo system to perform point loading on the lining model to form point loading test data; Step S43: When surface loading is selected, the valve is closed, and the hydraulic jack is started through the PLC system and the servo system to perform surface loading on the lining model to form surface loading test data; Step S44: When point-surface alternating loading is selected, the valve can be opened or closed regularly during the experiment, and the hydraulic jack can be started through the PLC system and the servo system to perform point-surface alternating loading on the lining model to form point-surface loading test data; Step S45: Compare and analyze the point loading test data, the surface loading test data, and the point-surface alternating loading test data.

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