A large component high internal pressure simulation test system and method of a central counter-force frame type

Abstract

The application discloses a center counter-force frame type large component high internal pressure simulation test system and method, which comprises a center cylinder counter-force frame system, an axial internal pressure balance system and an internal pressure loading system; the center cylinder counter-force frame system comprises a center cylinder counter-force frame and filling material located inside the center cylinder counter-force frame, an outer ring of the center cylinder counter-force frame is provided with a sample, and an annular gap is formed between the sample and an outer wall of the center cylinder counter-force frame; the axial internal pressure balance system comprises oil cylinders and an upper sealing plate arranged along a circumferential direction of the center cylinder counter-force frame, the oil cylinders are connected with the upper sealing plate, the upper sealing plate is installed on a top of the sample, a rodless cavity of the oil cylinder is communicated with the annular gap, and the sum of piston cross-sectional areas of the oil cylinders is equal to an area of the upper sealing plate for bearing liquid thrust; and the internal pressure loading system injects loading liquid into the annular gap to apply internal pressure, so that the influence of contact stress between the upper sealing plate and a supporting structure on the internal force distribution of the internal pressure load in the lining is effectively avoided.

Description

Technical Field

[0001] This invention relates to the engineering fields of high-pressure water diversion tunnels for water conservancy and hydropower, underground compressed air energy storage chambers, etc., and in particular to a high internal pressure simulation test system and method for large components with a central reaction frame. Background Technology

[0002] In engineering fields such as water conservancy and hydropower diversion tunnels and underground compressed air energy storage chambers, large-scale similar physical model tests are used to simulate the loading and failure of underground lining structures under different confining pressures and high internal pressure conditions. This is one of the important methods for studying the stability and sealing performance of underground structures under high internal pressure. Traditional model test equipment requires water or gas as the internal pressure transmission medium and relies on a complex and large reaction force system to balance the high internal pressure. On the one hand, under high internal pressure conditions, the sealing rings of such test equipment are prone to failure due to cyclic loading, which can lead to lining cracking. Moreover, due to the large size of the mechanism, there are many safety hazards. On the other hand, the huge axial reaction force affects the internal forces and safety of the lining structure. This requires that the contact stress between the reaction force system and the lining structure in the model test system cannot be too large, otherwise safety cannot be guaranteed during the internal pressurization process.

[0003] Existing internal uniform loading test devices are described in patent CN113029760A and the paper "Water Pressure Simulation Loading Method for Large Cross-Section Tunnel Model Test" - Engineering Mechanics, January 2015, Vol. 32, No. 1. However, existing internal uniform loading test devices have the following shortcomings:

[0004] (1) Traditional multi-point internal hydraulic cylinder or airbag loading methods are difficult to achieve precise internal loading and displacement control of the lining structure in the circumferential direction, especially precise loading and boundary condition control of repeated fatigue uniform load.

[0005] (2) The internal pressure transmission medium composed of gas with internal stress loading can only achieve a low internal pressure of 0.1MPA. When the sealing ring ages or the support structure breaks, it is easy to burst, making it difficult to ensure the safety of the experimental personnel.

[0006] (3) Traditional experimental devices are bulky and require a large amount of liquid as the internal pressure transmission medium. It is difficult to quickly input and output liquid to change the internal pressure. The operation is complicated and the effect is not ideal when conducting internal pressure fatigue tests.

[0007] (4) Existing experimental setups often require large reaction frames to balance the huge axial internal pressure, causing the test piece to be subjected to bidirectional stress, which deviates from the experimental ideas and concepts.

[0008] (5) The existing internal loading device and the structure under test are large in size, the test equipment is expensive, and the test cost is high, which restricts the size of the components from being too large. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high internal pressure simulation test system and method for large components with a central reaction frame. This device can realize the deformation and control of large components under high internal pressure, and achieve precise internal loading and displacement control of the support structure in the radial direction, especially the precise loading of cyclic and uniform loads and the control of boundary conditions.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] In a first aspect, embodiments of the present invention provide a high internal pressure simulation test system for large components with a central reaction frame, including a central cylindrical reaction frame system, an axial internal pressure balancing system, and an internal pressure loading system;

[0012] The central tube reaction frame system includes a central tube reaction frame and a filling material located inside the central tube reaction frame. A sample is placed on the outer ring of the central tube reaction frame, and an annular gap is formed between the sample and the outer wall of the central tube reaction frame.

[0013] The axial internal pressure balancing system includes a hydraulic cylinder and an upper sealing plate arranged along the circumference of the central cylindrical reaction frame. The hydraulic cylinder is connected to the upper sealing plate, which is installed on the top of the sample. The rodless chamber of the hydraulic cylinder is connected to the annular gap, and the sum of the cross-sectional areas of the hydraulic cylinder pistons is equal to the area of ​​the upper sealing plate that bears the liquid thrust.

[0014] The internal pressure loading system is used to inject loading fluid into the annular gap to apply internal pressure and expel air from the annular gap.

[0015] Furthermore, the hydraulic cylinder is fixed to the upper sealing plate of the reaction frame, and the upper sealing plate of the reaction frame is fitted onto the upper end of the central cylindrical reaction frame and fixed by a split circular anti-reverse ring.

[0016] As a further technical solution, the central cylindrical reaction frame is a hollow cylindrical structure with a base, and the diameter of the base is larger than the diameter of the cylindrical tube. The sample is fixed on the base of the cylindrical tube and fitted on the outer ring of the cylindrical tube, and is concentrically arranged with the cylindrical tube. An annular gap is formed between the sample and the outer wall of the cylindrical tube.

[0017] As a further technical solution, the contact surface between the sample and the base is sealed.

[0018] As a further technical solution, the contact surface between the sample and the upper sealing plate is sealed.

[0019] As a further technical solution, the inner ring of the upper sealing plate is fitted with the outer ring of the cylindrical tube with a clearance.

[0020] As a further technical solution, a test control system is also included. The test control system includes a control device and a data acquisition system, which controls the loading and cyclic loading, and statistically analyzes parameters such as the internal force borne by the specimen, the deformation of the specimen, and the fatigue strength.

[0021] As a further technical solution, the data acquisition device includes a strain sensor and a displacement sensor. The strain sensor is installed on the outside of the sample to detect the real-time strain in each direction of the sample surface, and the displacement sensor is installed in the circumferential direction of the sample to detect the length change in the circumferential direction of the sample.

[0022] Secondly, embodiments of the present invention also provide a testing method, comprising the following steps:

[0023] Step 1: Hoist the sample onto the central reaction frame, ensuring that the sample and the reaction frame are concentric and check the seal between the sample and the plane of the central reaction frame;

[0024] Step 2: Place the sample end face seal on the central reaction frame and make it contact the sample. Check the seal between the sealing plate and the central reaction frame and the seal between the sealing plate and the sample.

[0025] Step 3: Place the sealing plate of the reaction frame with multi-point hydraulic cylinders onto the central reaction frame;

[0026] Step 4: Install split circular anti-reverse rings on the outer ring of the sealing plate on the reaction frame;

[0027] Step 5: Inject the emulsion into the annular gap formed between the sample and the outer wall of the cylindrical tube, and conduct experimental observation.

[0028] The beneficial effects of the above embodiments of the present invention are as follows:

[0029] (1) The combination of the axial internal pressure balance system and the central reaction frame system of the present invention greatly reduces the magnitude of the axial reaction force that needs to be loaded, thereby effectively avoiding the influence of the internal pressure load on the internal force distribution in the specimen due to the large contact stress between the specimen end face seal and the support structure.

[0030] (2) The multi-point oil cylinder in the axial internal pressure balancing system can balance the reaction force generated by the high internal pressure at any time, ensuring reliable sealing under any test pressure and that the sample is not subjected to additional force in the axial direction, and can realize the cyclic loading function.

[0031] (3) The central reaction frame system occupies most of the volume inside the sample, which reduces the volume of the emulsion as the medium for internal pressure transmission. This allows for faster changes in internal pressure during cyclic loading and fatigue loading. Less emulsion effectively avoids lining cracking caused by aging failure of the sealing ring, improves operational safety, significantly reduces the manufacturing cost of the experimental device and the cost of the test process, and makes high internal pressure testing of large-volume components possible.

[0032] (4) The internal pressure loading system is equipped with multiple high-pressure servo pumps, which can meet the stress deformation test of the specimen under uniform loading, cyclic loading and long-term loading conditions, and the control system has an automated operation function. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0034] Figure 1 This is a schematic diagram of the external shape of the large component high internal pressure simulation test system with a central reaction frame proposed in this invention;

[0035] Figure 2 yes Figure 1 AA section view;

[0036] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0037] 1. Large high internal pressure specimen, 2. Central cylindrical reaction frame, 3. Upper sealing plate, 4. Upper sealing plate of reaction frame, 5. Central cylinder filler, 6. Split circular ring anti-reverse ring, 7. Multi-point hydraulic cylinder, 8. Specimen end face seal, 9. Internal pressure loading system. Detailed Implementation

[0038] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0039] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] As described in the background section, there are shortcomings in the existing technology. In order to solve the above-mentioned technical problems, this invention proposes a high internal pressure simulation test system and method for large components with a central reaction frame. This system and method are mainly used for high pressure simulation tests on large ring components, and the pressure can reach 20MPa.

[0042] In a typical embodiment of the present invention, such as Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a high internal pressure simulation test system for underground structures with a central reaction frame, including a central reaction frame system, an axial internal pressure balancing system, and an internal pressure loading system. The combination of the axial internal pressure balancing system and the central reaction frame system significantly reduces the magnitude of the axial reaction force required for loading, thereby effectively preventing the large contact stress between the specimen end face seal and the support structure from affecting the internal force distribution of the internal pressure load in the specimen. The multi-point hydraulic cylinders in the axial internal pressure balancing system can balance the reaction force generated by the high internal pressure at any time, ensuring reliable sealing under any test pressure and preventing the specimen from being subjected to additional axial forces. It can also achieve cyclic loading. The specific structures of each part are as follows:

[0043] The central reaction frame system includes a central cylindrical reaction frame 5 and a central cylindrical filler 5 located inside the central cylindrical reaction frame. The central cylindrical filler 5 fills the interior of the reaction frame to provide sufficient radial support for the central cylindrical reaction frame 5. The central cylindrical reaction frame 5 is installed inside the annular specimen and occupies most of the internal space of the specimen. Therefore, it can reduce the cross-sectional area that generates axial force by more than 90%, thereby reducing the impact of axial stress on the specimen and reducing the manufacturing cost of the reaction frame.

[0044] Furthermore, the aforementioned central cylindrical reaction frame 5 is a hollow cylindrical structure with a base, and the diameter of the base is larger than the diameter of the cylindrical tube. The sample is fixed on the base of the cylindrical tube and fitted onto the outer ring of the cylindrical tube, and is concentrically arranged with the cylindrical tube. An annular gap is formed between the sample and the outer wall of the cylindrical tube, and an emulsion is filled in the annular gap. The emulsion is used to apply radial pressure to the sample.

[0045] Furthermore, a sealing ring is provided on the contact surface between the sample and the base to prevent the emulsion from leaking from the contact surface during the test; specifically, a groove is opened on the top surface of the base, and the sealing ring is installed in the groove to achieve sealing of the contact surface between the sample and the base.

[0046] Furthermore, the central reaction frame system occupies most of the volume inside the sample, which reduces the volume of the emulsion that serves as the internal pressure transmission medium. This allows for faster changes in internal pressure during cyclic loading and fatigue loading. The reduced emulsion effectively prevents lining cracking caused by aging and failure of the sealing ring, improves operational safety, significantly reduces the manufacturing cost of the experimental device and the cost of the testing process, and makes high internal pressure testing of large-volume components possible.

[0047] The axial internal pressure balancing system in this embodiment includes an upper sealing plate 4 of the reaction frame, a split circular ring anti-reverse ring 6, a multi-point hydraulic cylinder 7, and an upper sealing plate 3. The upper sealing plate 4 of the reaction frame is fitted onto the cylindrical tube of the central cylindrical reaction frame 5 and fixed by the split circular ring anti-reverse ring 6. The upper sealing plate 4 of the reaction frame is fixedly connected to the vertically arranged multi-point hydraulic cylinder 7, and the multi-point hydraulic cylinder 7 is connected to the upper sealing plate 3. The upper sealing plate 3 is connected to the top of the sample. The rodless cavity of the multi-point hydraulic cylinder 7 communicates with the aforementioned annular gap. The sum of the cross-sectional areas of the pistons of the multi-point hydraulic cylinders is equal to the area of ​​the upper sealing plate that bears the liquid thrust, thereby achieving the balance of axial force under any pressure and ensuring that the sample is not subjected to additional axial force under any pressure.

[0048] In this embodiment, the axial internal pressure balancing system is located above the sample in the axial direction, and the split circular ring anti-reverse ring is located between the upper sealing plate and the central reaction frame, providing axial reaction force and facilitating the installation and disassembly of the sample and other components.

[0049] Furthermore, the aforementioned upper sealing plate 3 is an annular plate, and a groove is formed on the bottom of the annular plate in contact with the sample. A sealing ring is placed in the groove. The sealing ring is used to seal the contact surface between the upper sealing plate 3 and the sample to prevent the emulsion from leaking from the contact surface during the test.

[0050] Furthermore, the split circular anti-reverse ring 6 includes two semi-circular rings, which are connected by a connector; the two semi-circular rings are connected to the upper sealing plate 4 of the reaction frame, and the upper sealing plate 4 of the reaction frame is connected to the multi-point hydraulic cylinder 7.

[0051] Furthermore, the multi-point hydraulic cylinder 7 refers to a system comprising multiple hydraulic cylinders 7 arranged in a circle along the circumference of the upper sealing plate 4 of the reaction frame; and a typical hydraulic cylinder includes a rod-type chamber and a rodless chamber, wherein the rodless chamber communicates with the annular gap.

[0052] In this embodiment, the internal pressure loading system includes a plunger-type emulsion pump station, which injects emulsion into the annular gap formed between the sample and the outer wall of the cylindrical tube to apply internal pressure and expel air from the sample.

[0053] Furthermore, the aforementioned high internal pressure simulation test system for underground structures with a central reaction frame also includes a test control system, including a control device and a data acquisition system, which controls the loading and cyclic loading, and statistically analyzes parameters such as the internal force borne by the specimen, the deformation of the specimen, and the fatigue strength, and connects them to the test system; the test system includes various sensors, including strain sensors and displacement sensors. The strain sensors are installed on the outside of the specimen to detect the real-time strain in each direction of the specimen surface, and the displacement sensors are installed in the circumferential direction of the specimen to detect the length change in the circumferential direction of the specimen.

[0054] As a further implementation, the plunger-type emulsion pump station adopts a dual-pump structure consisting of a low-pressure high-flow pump and a high-pressure servo pump.

[0055] Secondly, embodiments of the present invention also provide a method for simulating high internal pressure in underground structures using a central reaction frame, the specific steps of which are as follows:

[0056] Step 1: Hoist the sample onto the base of the central reaction frame, ensuring that the sample and the reaction frame are concentric and check the seal between the sample and the plane of the central reaction frame; specifically, you can draw a circle of marking lines on the base beforehand, and then align the bottom of the sample with the marking lines to ensure concentricity.

[0057] Step 2: Place the upper sealing plate 3 on the central reaction frame and make it contact the top of the sample. Check the seal between the upper sealing plate 3 and the central reaction frame and the seal between the upper sealing plate 3 and the sample.

[0058] Step 3: Install the upper sealing plate 4 of the reaction frame with multi-point hydraulic cylinders onto the central reaction frame;

[0059] Step 4: Install the split circular anti-reverse ring 6 on the outer ring of the sealing plate 4 on the reaction frame;

[0060] Step 5: Inject emulsion into the annular gap formed between the sample and the outer wall of the cylindrical tube, and conduct experimental observation.

[0061] Finally, it should be noted that relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high internal pressure simulation test system for large components with a central reaction frame, characterized in that, This includes a central cylindrical reaction frame system, an axial internal pressure balance system, and an internal pressure loading system; The central tube reaction frame system includes a central tube reaction frame and a filling material located inside the central tube reaction frame. A sample is placed on the outer ring of the central tube reaction frame, and an annular gap is formed between the sample and the outer wall of the central tube reaction frame. The axial internal pressure balancing system includes a hydraulic cylinder and an upper sealing plate arranged along the circumference of the central cylindrical reaction frame. The hydraulic cylinder is connected to the upper sealing plate, which is installed on the top of the sample. The rodless chamber of the hydraulic cylinder is connected to the annular gap. The sum of the cross-sectional areas of the hydraulic cylinder pistons is equal to the area of ​​the upper sealing plate that bears the liquid thrust. This system achieves the balance of axial forces under any pressure, ensuring that the sample is not subjected to additional axial forces under any pressure. The internal pressure loading system is used to inject loading fluid into the annular gap to apply internal pressure and to expel air from the annular gap.

2. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 1, characterized in that, The central cylindrical reaction frame is a hollow cylindrical tube with a base, and the diameter of the base is larger than the diameter of the cylindrical tube. The sample is fixed on the base and fitted onto the outer ring of the cylindrical tube, and is concentrically arranged with the cylindrical tube. An annular gap is formed between the sample and the outer wall of the cylindrical tube.

3. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 2, characterized in that, The contact surfaces between the sample and the base are sealed.

4. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 2, characterized in that, The contact surface between the sample and the upper sealing plate is sealed.

5. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 2, characterized in that, The inner ring of the upper sealing plate is fitted with the outer ring of the cylindrical tube with a clearance and provides a seal.

6. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 1, characterized in that, The hydraulic cylinder is fixed on the upper sealing plate of the reaction frame, and the upper sealing plate of the reaction frame is fitted onto the upper end of the central cylindrical reaction frame and fixed by a split circular anti-reverse ring.

7. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 1, characterized in that, It also includes a test control system, which includes a control device and a data acquisition system. The control device controls the loading and cyclic loading, and the data acquisition system collects the internal forces borne by the specimen and the deformation data of the specimen.

8. The large-scale component high internal pressure simulation test system with a central reaction frame as described in claim 7, characterized in that, The data acquisition device includes a strain sensor and a displacement sensor. The strain sensor is installed on the outside of the sample to detect the real-time strain in each direction of the sample surface. The displacement sensor is installed in the circumferential direction of the sample to detect the length change in the circumferential direction of the sample.

9. A test method using the central reaction frame type high internal pressure simulation test system for large components as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Hoist the sample onto the central reaction frame, ensuring that the sample and the reaction frame are concentric and check the seal between the sample and the plane of the central reaction frame; (2) Place the end face sealing element of the sample on the central reaction frame and make it contact the sample to check the seal between the sealing plate and the central reaction frame and the seal between the sealing plate and the sample. (3) Place the sealing plate of the reaction frame with multi-point hydraulic cylinders onto the central reaction frame; (4) Install the split circular ring anti-reverse ring; (5) Inject emulsion into the annular gap formed between the sample and the outer wall of the cylindrical tube, and conduct experimental observation.

Images