A fatigue testing apparatus and method for thin film plates

Abstract

This invention proposes a fatigue testing device and method for thin film plates. The device comprises a bottom fixed plate with several sliding plates slidably mounted thereon, the sliding plates being located inside an annular limiting plate. The test plate includes a first part and several second parts. The first part is fixedly mounted on the bottom fixed plate, and the several second parts are respectively fixedly mounted on the several sliding plates. A driving mechanism is connected to each sliding plate. This invention achieves multiple folds simultaneously during the simulated filling and unloading process of the test plate by connecting the first part of the test plate to the bottom fixed plate and the several second parts of the test plate to the several sliding plates. The driving mechanism drives the sliding plates, thereby causing the several second parts of the test plate to fold and undergo fatigue testing. This improves the accuracy and reliability of the test.

Description

Technical Field

[0001] This invention pertains to fatigue testing devices, and specifically relates to a fatigue testing device and method for thin film plates. Background Technology

[0002] With the promotion of energy conservation and emission reduction and the construction of an environmentally friendly society, liquefied natural gas (LNG) is increasingly used in transportation, energy and other fields due to its clean and efficient performance advantages. It is also pointed out that natural gas should be developed into one of the main energy sources in the modern clean energy system.

[0003] LNG, as a clean and high-quality energy source, is crucial for major energy-consuming countries to diversify their energy supply and ensure energy security. With the increasingly widespread use of natural gas in national and social contexts, the domestic LNG supply-demand gap is widening, urgently requiring innovative advancements in LNG storage technology research.

[0004] LNG membrane tanks are a safer and more reliable type of liquefied natural gas storage tank compared to other types. However, throughout the tank's lifespan, there are multiple loading, unloading, and cleaning processes. During these processes, the inner container deforms due to temperature changes. Repeated deformation can lead to metal fatigue, resulting in metal embrittlement, fatigue cracks, and ultimately, dangerous situations such as tank leaks. Currently, fatigue tensile tests provided by major laboratories and testing institutions are uniaxial tensile tests. To obtain more data, multiple tensile devices are needed to tensile multiple test steel plates, thus requiring multiple tensile devices and wasting resources. Furthermore, during the use of storage tanks, the steel plates used in the tanks are folded in multiple places simultaneously due to the loading and unloading of liquefied natural gas.

[0005] Therefore, in order to more realistically reflect the usage of the steel plates in the storage tank, a device is needed that can repeatedly simulate fatigue tests of steel plates folding at multiple points at the same time. Summary of the Invention

[0006] To address the above problems, this invention proposes a film plate fatigue testing device, comprising a fixedly connected annular limiting plate and a bottom fixing plate;

[0007] A plurality of sliding plates are slidably mounted on the bottom fixed plate, and the plurality of sliding plates are located inside the annular limiting plate; a test plate is mounted on the bottom fixed plate and the plurality of sliding plates;

[0008] The test plate includes a first part and several second parts. The first part is fixedly mounted on a bottom fixed plate, and the several second parts are respectively fixedly mounted on several sliding plates. A driving mechanism is connected to the sliding plates.

[0009] Furthermore, the test plate, after being folded, forms a protrusion between the first and second parts.

[0010] Furthermore, the protrusion is an isosceles triangle.

[0011] Furthermore, the driving mechanism includes a push pin, a first driving electric cylinder, and a second driving electric cylinder. The push pin passes through the central circular hole of the bottom fixed plate and slides in contact with several sliding plates. The other end of the push pin is connected to the first driving electric cylinder. The second driving electric cylinder is connected to the outside of the sliding plate.

[0012] Furthermore, a spacing matching block is provided between the annular limiting plate and the bottom fixing plate, and the spacing matching block is located at the corner of the annular limiting plate and the bottom fixing plate.

[0013] Furthermore, the device also includes a push slider, which is slidably mounted between the annular limiting plate and the bottom fixing plate and located between adjacent spacing matching blocks, and the push slider is connected to the second drive electric cylinder.

[0014] Furthermore, the connection points of the sliding plates are provided with arc-shaped grooves, and the arc-shaped grooves of the sliding plates are spliced ​​together to form a circular groove.

[0015] Furthermore, the device also includes a pad, which is installed in the arcuate groove of the sliding plate, and the end of the pad away from the bottom fixing plate is connected to the test plate. The test plate, the pad, and the bottom fixing plate are fixedly connected.

[0016] Furthermore, the spacing matching block is L-shaped or elongated.

[0017] A method for fatigue testing of a thin film plate, using the aforementioned thin film plate fatigue testing apparatus, includes the following steps:

[0018] The test plate is fixed to the bottom fixing plate and several spacing matching blocks;

[0019] The first drive electric cylinder drives the ejector pin, which in turn pushes the sliding plate to move away from the ejector pin.

[0020] The reset is completed by moving the sliding plate toward the ejector pin using the second drive electric cylinder;

[0021] Repeat the above steps until the fatigue test of the test plate is completed.

[0022] Beneficial effects of this invention:

[0023] 1. This invention fixes the first part of the test plate to the bottom fixed plate, and fixes several second parts of the test plate to several sliding plates. By connecting the sliding plates to a driving mechanism, the sliding plates are driven to fold the several second parts of the test plate for fatigue testing. This enables the test plate to be folded in multiple places at the same time during the simulated filling and unloading process, thereby improving the accuracy and reliability of the test.

[0024] 2. The present invention provides a spacing matching block between the annular limiting plate and the bottom fixing plate, thereby enabling the spacing matching block to provide an appropriate height, allowing the sliding plate to slide smoothly between the annular limiting plate and the bottom fixing plate.

[0025] 3. The present invention includes a pad, which is installed in the arcuate groove of the sliding plate, and the other end of the pad is connected to the test plate. The pad is used to connect the first part of the test plate and to limit the sliding plate, thereby ensuring that the first part and the second part of the test plate being tested are on the same plane, thus ensuring the stability and safety of the test.

[0026] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 An exploded structural diagram of the fatigue testing device for the inner plate of the thin film tank in Embodiment 1 of the present invention is shown.

[0029] Figure 2 A top view of the fatigue testing device for the inner plate of the thin film tank in Embodiment 1 of the present invention is shown.

[0030] Figure 3 A schematic flowchart of the fatigue test method for the inner plate of the thin film tank in Embodiment 2 of the present invention is shown.

[0031] In the diagram, 1 is the test plate; 2 is the pad; 3 is the annular limiting plate; 4 is the sliding plate; 5 is the spacing matching block; 6 is the pushing slider; 7 is the bottom fixing plate; 8 is the ejector pin; 9 is the connecting bolt; and 10 is the fixing bolt. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Figure 1 An exploded structural diagram of the fatigue testing device for the inner container of the thin-film tank in Embodiment 1 of the present invention is shown. (Reference) Figure 1 A film plate fatigue testing device includes an annular limiting plate 3 and a bottom fixing plate 7 fixedly connected; and there is a gap between the annular limiting plate 3 and the bottom fixing plate 7; specifically, the annular limiting plate 3 plays a limiting role, which is used to limit the displacement range of the sliding plate 4, and at the same time, there is a gap between the annular limiting plate 3 and the bottom fixing plate 7 for driving the limiting sliding plate 4 to reset.

[0034] Several sliding plates 4 are slidably mounted on the bottom fixed plate 7, and the several sliding plates 4 are located inside the annular limiting plate 3; the test plate 1 includes a first part and several second parts (see reference). Figure 2 The first part is fixedly mounted on the bottom fixed plate 7, and several second parts are respectively fixedly mounted on several sliding plates 4. The test plate 1 has protrusions located between the first and second parts; a driving mechanism is connected to the sliding plates 4. Specifically, the driving mechanism drives the multiple sliding plates 4 to move in all directions, thereby moving several second parts of the test plate 1, thus flattening and folding the protrusions between the first and second parts of the test plate 1, simulating the filling and unloading process. The test plate 1 is a thin-film steel plate or a corrugated plate.

[0035] In this invention, the protrusion is an isosceles triangle. For example... Figure 1 As shown, Figure 1 The central protrusion is located between the first and second parts, and the simulated filling and unloading process is completed by flattening and folding the protrusion.

[0036] In accordance with the embodiments of the present invention, the driving mechanism includes a push pin 8, a first driving electric cylinder, and a second driving electric cylinder. The push pin 8 passes through the central circular hole of the bottom fixing plate 7 and slides in contact with several sliding plates 4. The other end of the push pin 8 is connected to the first driving electric cylinder; the second driving electric cylinder is connected to the outer side of the sliding plates 4. Specifically, by the alternating extension and retraction of the first and second driving electric cylinders, the several sliding plates 4 are driven to move away from the push pin 8 and towards the push pin 8, thereby realizing the repeated simulation of the filling and unloading process. Figure 1As shown, there are eight sliding plates 4, which are spliced ​​together to form a square. When the ejector pin 8 moves upward, the eight sliding plates 4 are pushed open and move away from the ejector pin 8. Under the action of force, the test plate 1 is stretched outward as a whole through the connecting bolt 9. When stretched to the required length, the ejector pin 8 moves downward to the initial state, and then pushes the slider 6 to move inward under the push of the second drive electric cylinder to compress the test plate 1 to the initial state, and then returns to the initial position. At this time, one simulated filling and unloading process is completed.

[0037] In this invention, a spacing matching block 5 is provided between the annular limiting plate 3 and the bottom fixing plate 7, and the spacing matching block 5 is located at the corners of the annular limiting plate 3 and the bottom fixing plate 7. Specifically, the spacing matching block 5 is L-shaped and elongated. The L-shaped spacing matching block 5 is welded sequentially to the four corners of the bottom fixing plate 7, and the elongated spacing matching block 5 is welded between two adjacent L-shaped spacing matching blocks 5 to limit the sliding plate 4; the annular limiting plate 3 is welded to the side of the L-shaped and elongated spacing matching blocks 5 away from the bottom fixing plate 7. The spacing matching block 5 provides an appropriate height, allowing the sliding plate 4 to slide smoothly between the annular limiting plate 3 and the bottom fixing plate 7.

[0038] Furthermore, the device also includes a push slider 6, which is slidably mounted between the annular limiting plate 3 and the bottom fixing plate 7, and located between adjacent spacing matching blocks 5. The push slider 6 is connected to the second drive electric cylinder. Specifically, the push slider 6 serves as a connector, mainly used to connect the second drive electric cylinder and the sliding plate 4, with the push slider 6 in contact with the sliding plate 4. The push slider 6 is externally connected to a drive electric cylinder, a hydraulic cylinder, or a pneumatic actuation device (not shown in the attached drawings).

[0039] In accordance with the embodiments of the present invention, arc-shaped grooves are provided at the joints of several sliding plates 4, and the arc-shaped grooves of several sliding plates 4 are spliced ​​together to form a circular groove. The circular groove is used to place the pad 2, and the pad 2 is flush with the upper surface of the sliding plate 4.

[0040] The device also includes a pad 2, which is installed in the arcuate groove of the sliding plate 4, and the other end of the pad 2 is connected to the test plate 1. The pad 2 is used to connect the first part of the test plate 1 and to limit the sliding plate 4. This ensures that the first and second parts of the test plate 1 being tested are on the same plane, thereby guaranteeing the stability and safety of the test.

[0041] Combined with the present invention Figure 1The device also includes fixing bolts 10, which pass through the test plate 1, pad 2, sliding plate 4, and bottom fixing plate 7 in sequence for fixed connection. The fixing bolts 10 securely connect the first part of the test plate 1 to the pad 2 and bottom fixing plate 7. The device also includes connecting bolts 9, which pass through the test plate 1 and securely connect to the sliding plate 4. The connecting bolts 9 are used to securely connect the second part of the test plate 1 to the sliding plate 4, thereby enabling the sliding plate 4 to move the second part of the test plate 1, completing the simulation test.

[0042] In the above embodiments, another optional implementation is that the fixing device is composed of a pad 2, an annular limiting plate 3, a spacing matching block 5, a bottom fixing plate 7, and fixing bolts 10, which provides a fixed constraint for the steel plate. The fixing method is bolt connection, or the fixing bolts 10 can be omitted and welding connection can be used instead.

[0043] The sliding device consists of an annular limiting plate 3, a sliding plate 4, a spacing matching block 5, a pushing slider 6, a bottom fixing plate 7, and a push pin 8. The spacing matching block 5 provides an appropriate clearance to ensure the smooth sliding of the sliding plate 4. Similarly, the sliding plate 4 can be constrained by a slide rail or bushing to make it slide.

[0044] For ease of disassembly, this device uses bolt connections. However, welding is also feasible for verifying other properties of the steel plate. Both the slider 6 and the ejector pin 8 require external power equipment to provide the forces required for the steel plate to stretch and contract. This power equipment can be any pneumatic or electric device; if necessary, a spring whose reliability needs to be verified can also be used.

[0045] It should be noted that the sliding plate 4 is composed of multiple sets of small sliding plates. The number of small sliding plates is not fixed and is determined by the size of the steel plate being tested. The outer contour shape of the sliding plate 4 can be arbitrary. The outer diameter and chamfer of the ejector pin 8 are determined by the material, temperature difference, and size of the plate being tested. The function of the ejector pin 8 is only to provide an outward force for the slider, and its function can be replaced by other similar structures.

[0046] Example 2

[0047] refer to Figure 3 A method for fatigue testing of thin film plates, using the thin film plate fatigue testing apparatus described in Example 1, includes the following steps:

[0048] The test plate 1 is fixed on the bottom fixing plate 7 and several spacing matching blocks 5;

[0049] The first drive electric cylinder drives the ejector pin 8, which in turn pushes the sliding plate 4 to move away from the ejector pin 8.

[0050] The reset is completed by moving the sliding plate 4 toward the ejector pin 8 via the second drive electric cylinder;

[0051] Repeat the above steps until the fatigue test of test plate 1 is completed.

[0052] Preparation before work: First, drill a hole in the center of the bottom fixing plate 7, and then tap threaded holes or drill through holes around the center hole;

[0053] Multiple L-shaped spacing matching blocks 5 are sequentially welded to the four corners of the bottom fixing plate 7, and a long strip-shaped spacing matching block 5 is welded between two adjacent L-shaped spacing matching blocks 5. The long strip-shaped spacing matching block 5 is used to limit the sliding plate 4. The annular limiting plate 3 is welded to the side of the L-shaped spacing matching block 5 and the long strip-shaped spacing matching block 5 away from the bottom fixing plate 7.

[0054] A conical hole is provided at the junction of several triangular sliding plates 4. The taper of the conical hole is the same as the taper of the ejector pin 8, and the angle is consistent, so that the ejector pin 8 can push the sliding plate 4 open. Several sliding plates 4 are spliced ​​together to form a complete circular hole. The diameter of the circular hole is larger than the diameter of the tip of the ejector pin 8 and smaller than the diameter of the bottom of the ejector pin 8. Threaded holes are tapped on the sliding plates 4, and strip grooves are provided on the sliding plates 4. The strip grooves are used for sliding installation with the fixing bolt 10. Arc grooves are provided at the junction of the triangular sliding plates 4. Several sliding plates 4 are spliced ​​together to form a complete circular groove. The end of the ejector pin 8 away from the tip is connected to the first drive motor.

[0055] Several triangular sliding plates 4 are spliced ​​together and placed on top of the bottom fixed plate 7, and positioned between several L-shaped spacing matching blocks 5 and several long strip-shaped spacing matching blocks 5; the pad 2 is installed in a complete circular groove after the several sliding plates 4 are spliced ​​together, and the pad 2 is flush with the sliding plates 4.

[0056] A test plate 1 is installed on the upper surface of the pad 2 and the sliding plate 4. The center of the test plate 1 is fixedly connected to the bottom fixing plate 7 by a fixing bolt 10 passing through the groove of the pad 2 and the sliding plate 4. A connecting bolt 9 passes through the test plate 1 and is fixedly connected to the sliding plate 4. A round hole is drilled in the center of the test plate 1. The round hole is coaxial with the round hole of the pad 2, the conical hole of the sliding plate 4, and the round hole of the bottom fixing plate 7.

[0057] The push slider 6 is installed between the annular limiting plate 3 and the bottom fixing plate 7, and is located inside the spacing matching block 5. One end of the push slider 6 is in contact with the sliding plate 4, and the other end is connected to the second drive electric cylinder.

[0058] Working principle: When using this invention, the bottom fixing plate 7 is fixed on the designated workbench, and the first driving electric cylinder drives the ejector pin 8 to move towards the test plate 1, thereby pushing the sliding plate 4 to move outward, which in turn causes the sliding plate 4 to move the test plate 1 outward, thus flattening the test plate 1 with protrusions. Then, the first driving electric cylinder drives the ejector pin 8 to move away from the test plate 1, and then the second driving electric cylinder drives the push slider 6 to push the sliding plate 4 and move the test plate 1 towards the center of the bottom fixing plate 7, completing the reset. After that, the above steps are repeated to perform a second folding and flattening test.

[0059] This invention improves testing accuracy and reliability. The device is specifically designed for plate fatigue testing of the inner container of a diaphragm tank, accurately simulating stress changes under actual working conditions to ensure high accuracy and reliability of test results (achieved by precisely adjusting the extension and retraction length and thrust of the first and second drive cylinders, thus accurately simulating stress changes under actual working conditions). This high-precision testing helps to better evaluate the performance stability of the diaphragm tank during long-term operation, providing a scientific basis for product design optimization.

[0060] This invention enhances testing efficiency and flexibility: by adopting advanced control technology and automated testing processes (by setting the extension and retraction frequency of the first and second drive cylinders), the equipment can efficiently complete various complex fatigue test tasks, while supporting the rapid replacement and adjustment of the contents of the membrane tank of different sizes (i.e., by replacing the sliding plate 4 of different sizes to adapt to the test plate 1 of different sizes), which greatly improves the flexibility and efficiency of testing and shortens the new product development cycle.

[0061] This device ensures operational safety and environmental protection: its design fully considers the safety of operators and environmental protection requirements (by setting an annular limiting plate 3 to limit the movement path of the sliding plate 4, and by setting a pad plate 2 to connect the test plate 1, the connection of the test plate 1 is made more secure), and is equipped with comprehensive safety protection measures and a leakage detection system, which can take protective measures in a timely manner in case of abnormal situations to avoid potential risks.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fatigue testing device for thin film plates, characterized in that, It includes a fixedly connected annular limiting plate (3) and a bottom fixing plate (7); A plurality of sliding plates (4) are slidably mounted on the bottom fixing plate (7), and the plurality of sliding plates (4) are located inside the annular limiting plate (3); a test plate (1) is mounted on the bottom fixing plate (7) and the plurality of sliding plates (4); The test plate (1) includes a first part and several second parts. The first part is fixedly installed on the bottom fixed plate (7), and the several second parts are respectively fixedly installed on several sliding plates (4). A driving mechanism is connected to the sliding plate (4).

2. The film plate fatigue testing device according to claim 1, characterized in that, The test plate (1) forms a protrusion between the first part and the second part after being folded.

3. The film plate fatigue testing device according to claim 2, characterized in that, The protrusion is an isosceles triangle.

4. The film plate fatigue testing device according to claim 1, characterized in that, The driving mechanism includes a push pin (8), a first driving electric cylinder and a second driving electric cylinder. The push pin (8) passes through the central circular hole of the bottom fixing plate (7) and slides in contact with several sliding plates (4). The other end of the push pin (8) is connected to the first driving electric cylinder. The second driving electric cylinder is connected to the outside of the sliding plate (4).

5. The film plate fatigue testing device according to claim 1, characterized in that, A spacing matching block (5) is provided between the annular limiting plate (3) and the bottom fixing plate (7), and the spacing matching block (5) is located at the corner of the annular limiting plate (3) and the bottom fixing plate (7).

6. The film plate fatigue testing device according to claim 5, characterized in that, The spacing matching block (5) is L-shaped or elongated.

7. A film plate fatigue testing device according to claim 5 or 6, characterized in that, The device also includes a push slider (6), which is slidably mounted between the annular limiting plate (3) and the bottom fixing plate (7) and located between adjacent spacing matching blocks (5). The push slider (6) is connected to the second drive electric cylinder.

8. The film plate fatigue testing device according to claim 1, characterized in that, A circular arc groove is provided at the connection of several sliding plates (4), and the circular arc grooves of several sliding plates (4) are spliced ​​together to form a circular groove.

9. The film plate fatigue testing device according to claim 8, characterized in that, The device also includes a pad (2), which is installed in the arc groove of the sliding plate (4), and the end of the pad (2) away from the bottom fixing plate (7) is connected to the test plate (1). The test plate (1), the pad (2) and the bottom fixing plate (7) are fixedly connected.

10. A fatigue testing method for a thin film plate, characterized in that, The thin film plate fatigue testing apparatus according to any one of claims 1-9 includes the following steps: The test plate (1) is fixed on the bottom fixing plate (7) and several spacing matching blocks (5); The first drive electric cylinder drives the ejector pin (8), which in turn pushes the sliding plate (4) to move away from the ejector pin (8); The reset is completed by driving the sliding plate (4) to move towards the ejector pin (8) by the second drive electric cylinder; Repeat the above steps until the fatigue test of the test plate (1) is completed.

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