Modal test tool and modal test system

Abstract

The utility model discloses a modal test tool and a modal test system, and the modal test tool comprises a piezoelectric ceramic plate which can be fixedly disposed on the inner wall surface of a test tube body, a pasting expansion rod disposed in the test tube body, a variable-diameter rod disposed in the pasting expansion rod, and a driving power supply which is electrically connected with the piezoelectric ceramic plate. A positioning groove for containing the piezoelectric ceramic plate is formed in the pasting expansion rod, and an expansion hole for containing the variable-diameter rod is formed in the center of the pasting expansion rod. According to the modal test tool, the problem that a conventional excitation system cannot be used in a non-waterproof and non-temperature-resistant environment is solved, the piezoelectric ceramic plate is simple and convenient to install through the arrangement of the sticking expansion rod and the variable-diameter rod, meanwhile, the high-temperature-resistant piezoelectric ceramic plate is connected with the driving power supply, self-excitation excitation of a tube bundle structure in a high-temperature environment can be achieved, and the service life of the tube bundle structure is prolonged. The problem that the test area of the test body cannot be directly excited is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of structural vibration dynamics, in particular to a modal testing tool and a modal testing system. Background Art

[0002] At present, the conventional method for modal testing of the steam generator tube bundle structure is to use an exciter or a force hammer to perform a tube bundle modal test. The force hammer method can only be used for tube bundle modal testing in an air environment. Since the force hammer is not waterproof, the force hammer can only hit the outer shell of the test body in a water environment. This will lead to insufficient excitation of the tube bundle and the introduction of the external shell frequency into the test results, which is not conducive to the analysis of the test results. The exciter method can be used in air and water environments, but when used in a water environment, it is necessary to open a hole in the test body and perform special sealing treatment on the opening position. In addition, the test tube in the middle tube bundle test area requires special design, and it is inconvenient to replace different test tubes. When using an exciter in a high-temperature and high-pressure liquid metal environment, conventional sealing methods are prone to failure and leakage, and even burns. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a modal testing tool and a modal testing system.

[0004] The technical solution adopted by the utility model to solve the technical problem is: construct a modal test fixture, which is installed on a test tube body, and includes a piezoelectric ceramic plate that can be fixedly installed on the inner wall surface of the test tube body, an expansion rod installed in the test tube body, a diameter-changing rod installed in the expansion rod, and a driving power supply electrically connected to the piezoelectric ceramic plate;

[0005] The expansion rod is provided with a positioning groove for accommodating the piezoelectric ceramic plate, and the center of the expansion rod is provided with an expansion hole for accommodating the diameter-changing rod. When the diameter-changing rod is located in the expansion hole, the expansion rod expands and presses the piezoelectric ceramic plate, so that the piezoelectric ceramic plate is tightly attached to the inner wall surface of the test tube body.

[0006] In some embodiments, an expansion groove is provided on the expansion rod, and the expansion groove is connected to the outer wall surface of the expansion rod and the expansion hole.

[0007] In some embodiments, a wire groove is provided on the expansion rod.

[0008] In some embodiments, the piezoelectric ceramic plate and the inner wall surface of the test tube body are connected together by glue.

[0009] In this embodiment, a modal testing system is also constructed, which includes the above-mentioned modal testing tool, a test body and a test tube body installed on the test body, and the modal testing tool is installed on the test tube body.

[0010] In some embodiments, the test body includes a test base and a test positioning seat detachably connected to the test base, and the test base and the test positioning seat are connected together by fasteners.

[0011] In some embodiments, the test base is provided with a mounting hole for mounting the test tube body, the test tube body is passed through the mounting hole, and the test tube body is connected to the test base by welding.

[0012] In some embodiments, a receiving groove is provided on a side of the test positioning seat facing the test base, and the test tube body is at least partially located in the receiving groove.

[0013] In some embodiments, the receiving tank is filled with a medium.

[0014] In some embodiments, the medium is high temperature liquid metal or liquid water.

[0015] The implementation of the utility model has the following beneficial effects: the modal test fixture solves the problem that the conventional excitation system cannot be used in a non-waterproof and non-temperature-resistant environment. The setting of the expansion rod and the reducer rod makes the installation of the piezoelectric ceramic plate simple and convenient. At the same time, by connecting the high-temperature resistant piezoelectric ceramic plate to the driving power supply, the self-excitation of the tube bundle structure in a high-temperature environment can be achieved, solving the problem that the test area of ​​the test body cannot be directly excited. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0017] Figure 1 is a schematic diagram of the overall structure of a modal testing system in some embodiments of the utility model;

[0018] Figure 2 It is a schematic structural diagram of the expansion rod in some embodiments of the utility model. DETAILED DESCRIPTION

[0019] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0020] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0021] See also Figure 1 and Figure 2 , is a schematic diagram of the application of a modal test fixture in some embodiments of the utility model. The modal test fixture can be used for self-excitation of the tube bundle structure in a water environment or a high-temperature liquid metal environment for modal testing. It is mainly used to study the modal test of the steam generator cantilever beam straight tube bundle or curved tube bundle test piece structure. At the same time, it can also realize the modal test of other flexible tube bundle structures in a water environment or a high-temperature liquid metal environment, and provide vibration characteristic test parameters for the steam generator structure design, which is of great significance. In this embodiment, a modal test system is also constructed, which includes the above-mentioned modal test fixture, a test body 6, and a test tube body 1 installed on the test body 6, and the modal test fixture is installed on the test tube body 1.

[0022] like Figure 1As shown, the modal test fixture includes a piezoelectric ceramic plate 2 that can be fixedly mounted on the inner wall surface of the test tube body 1, an expansion rod 3 installed in the test tube body 1, a variable diameter rod 4 installed in the expansion rod 3, and a driving power supply 5 electrically connected to the piezoelectric ceramic plate 2. Among them, the piezoelectric ceramic sheet is a ceramic material with a piezoelectric effect. When mechanical pressure or an electric field is applied, charge separation and potential difference can be generated, which can convert electrical energy into mechanical vibration energy, thereby being applied to the modal test of the tube bundle structure. The driving power supply 5 is electrically connected to the piezoelectric ceramic plate 2. The operator can start the driving power supply 5 by inputting the excitation voltage, sinusoidal sweep frequency range (or fixed frequency), sweep frequency rate and other parameters on the control panel of the driving power supply 5. Then the piezoelectric ceramic plate 2 will vibrate according to the set parameters, thereby driving the test tube body 1 to vibrate, thereby realizing the self-excitation modal test of the tube bundle structure.

[0023] like Figure 2 As shown, the expansion rod 3 is provided with a positioning groove 31 for accommodating the piezoelectric ceramic plate 2, and a space for accommodating the piezoelectric ceramic plate 2 is formed between the positioning groove 31 and the inner wall surface of the test tube body 1, and an expansion hole 32 for accommodating the diameter-changing rod 4 is provided at the center of the expansion rod 3. When the diameter-changing rod 4 is located in the expansion hole 32, the expansion rod 3 expands and presses the piezoelectric ceramic plate 2, so that the piezoelectric ceramic plate 2 is closely attached to the inner wall surface of the test tube body 1. It can be understood that the expansion rod 3 is made of polytetrafluoroethylene material, which has a certain toughness and is resistant to high temperature. The test tube body 1 and the diameter-changing rod 4 are both made of stainless steel material, which has a certain strength and is resistant to high temperature. The diameter of the diameter-changing rod 4 is larger than the diameter of the expansion hole 32. When the diameter-changing rod 4 is inserted into the expansion hole 32, the expansion rod 3 is forced to expand and press the piezoelectric ceramic plate 2, so that the piezoelectric ceramic plate 2 is closely attached to the inner wall surface of the test tube body 1.

[0024] The piezoelectric ceramic plate 2 and the inner wall of the test tube body 1 can be connected together by glue. When the expansion rod 3 is expanded and pressed against the piezoelectric ceramic plate 2, so that the piezoelectric ceramic plate 2 and the inner wall of the test tube body 1 are closely attached, after the glue is cured, the reducing rod 4 is first removed, and then the expansion rod 3 is removed, and then the piezoelectric ceramic plate 2 is connected to the driving power supply 5.

[0025] An expansion groove 33 is provided on the expansion rod 3, and the expansion groove 33 is connected to the outer wall surface of the expansion rod 3 and the expansion hole 32. The expansion groove 33 is used to provide a certain deformation space for the expansion deformation of the expansion rod 3 to prevent the expansion rod 3 from being damaged due to excessive expansion of the expansion rod 3.

[0026] In addition, a wire groove 34 is provided on the expansion rod 3. Since there will be a sensor in the test tube body for modal testing, the wire groove 34 can be used for the wires connected to the sensor to pass through.

[0027] Furthermore, the test body 6 includes a test base 61 and a test positioning seat 62 detachably connected to the test base 61 . The test base 61 and the test positioning seat 62 are connected together by a fastener, which may be a bolt.

[0028] The test base 61 is provided with a mounting hole 611 for installing the test tube body 1. The test tube body 1 and the mounting hole 611 are preferably circular in shape. The diameter of the test tube body 1 is substantially the same as the diameter of the mounting hole 611. The test tube body 1 is passed through the mounting hole 611, and the test tube body 1 and the test base 61 are connected by welding to ensure the overall sealing of the device during the modal test.

[0029] A receiving groove 621 is provided on one side of the test positioning seat 62 facing the test base 61, and the test tube body 1 is at least partially located in the receiving groove 621, and the receiving groove 621 is filled with a medium. More specifically, a filling space is provided between the portion of the test tube body 1 located in the receiving groove 621 and the receiving groove 621, and the filling space is filled with a medium, and the medium is high-temperature liquid metal or liquid water, so that the test body 6 is in a water environment or a high-temperature liquid metal environment to realize self-excitation for modal testing.

[0030] To summarize, the working principle of the modal testing system is as follows: the modal testing tooling mainly includes four parts: a piezoelectric ceramic plate 2, an expansion rod 3, a reducing rod 4 and a driving power supply 5. The modal testing system uses a test tube body 1 as a pressure boundary, and the filling space between the test tube body 1 and the receiving groove 621 is filled with liquid water or high-temperature liquid metal, so that the test body 6 is in a water environment or a high-temperature liquid metal environment to achieve self-excitation for modal testing, and the test tube body 1 is connected to the modal testing tooling, and the test tube body 1 is welded to the test body 6 to ensure that liquid water or high-temperature liquid metal does not leak.

[0031] The specific application and installation process of the modal test fixture is as follows:

[0032] 1. Apply glue to the designated installation position on the inner wall of the test tube body 1 in advance;

[0033] 2. Install the piezoelectric ceramic plate 2 into the positioning groove 31 on the expansion rod 3, and then extend the expansion rod 3 into the designated installation position in the test tube body 1;

[0034] 3. Then insert the reducer rod 4 into the expansion hole 32 of the expansion rod 3 to achieve a close fit between the piezoelectric ceramic plate 2 and the inner wall of the test tube 1. After the glue is cured, remove the reducer rod 4 and then the expansion rod 3, and then connect the piezoelectric ceramic plate 2 to the driving power supply 5;

[0035] 4. Input the excitation voltage, sinusoidal sweep frequency range (or fixed frequency), sweep frequency rate and other parameters on the control panel of the driving power supply 5 and start it. Then the piezoelectric ceramic plate 2 will vibrate according to the set parameters, thereby driving the test tube body 1 to vibrate, thereby realizing the self-excitation modal test of the test body 6.

[0036] In summary, the beneficial effects of the modal test fixture and the modal test system are:

[0037] 1. This modal test fixture solves the problem that conventional excitation systems cannot be used in non-waterproof and non-temperature-resistant environments. Its special structure can achieve the excitation of the tube bundle structure;

[0038] 2. This modal test fixture solves the problem that the test area 6 of the test body cannot be directly excited;

[0039] 3. The modal test fixture is connected to the driving power supply 5 through the high temperature resistant piezoelectric ceramic plate 2 to realize the self-excitation of the tube bundle structure in a high temperature environment;

[0040] 4. The modal test fixture has a simple structure, is compact and easy to install;

[0041] 5. The modal test system can be used in high temperature and high pressure environments. Since the test tube body serves as the pressure boundary, it is guaranteed to withstand a pressure of 1.0Mpa and the maximum temperature can reach 200℃;

[0042] 6. The modal test fixture can be used in conventional air and water environments, as well as for tube bundle vibration characteristic tests in liquid metal environments, thus ensuring economy, ease of operation, effective functionality and safety.

[0043] In general, the modal test fixture solves the problem that conventional excitation systems cannot be used in non-waterproof and non-temperature-resistant environments. The setting of expansion rods and reducer rods makes the installation of piezoelectric ceramic plates simple and convenient. At the same time, by connecting the high-temperature resistant piezoelectric ceramic plates to the driving power supply, self-excitation of the tube bundle structure in a high-temperature environment can be achieved, solving the problem that the test area of ​​the test body cannot be directly excited.

[0044] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.

Claims

1. A modal test fixture, which is mounted on a test tube body (1), characterized in that: It comprises a piezoelectric ceramic plate (2) that can be fixedly mounted on the inner wall surface of the test tube body (1), an expansion rod (3) mounted in the test tube body (1), a diameter-changing rod (4) mounted in the expansion rod (3), and a driving power source (5) electrically connected to the piezoelectric ceramic plate (2); The expansion rod (3) is provided with a positioning groove (31) for accommodating the piezoelectric ceramic plate (2), and the center of the expansion rod (3) is provided with an expansion hole (32) for accommodating the diameter-changing rod (4); when the diameter-changing rod (4) is located in the expansion hole (32), the expansion rod (3) expands and presses the piezoelectric ceramic plate (2), so that the piezoelectric ceramic plate (2) is tightly attached to the inner wall surface of the test tube body (1).

2. The modal testing tool according to claim 1, characterized in that: The expansion rod (3) is provided with an expansion groove (33), and the expansion groove (33) is connected to the outer wall surface of the expansion rod (3) and the expansion hole (32).

3. The modal testing tool according to claim 1, characterized in that: The expansion rod (3) is provided with a wire groove (34).

4. The modal testing tool according to claim 1, characterized in that: The piezoelectric ceramic plate (2) and the inner wall surface of the test tube body (1) are connected together by glue.

5. A modal testing system, characterized in that: It comprises the modal test fixture according to any one of claims 1 to 4, a test body (6), and a test tube body (1) mounted on the test body (6).

6. The modal testing system according to claim 5, characterized in that: The test body (6) comprises a test base (61) and a test positioning seat (62) detachably connected to the test base (61); the test base (61) and the test positioning seat (62) are connected together via fasteners.

7. The modal testing system according to claim 6, characterized in that: The test base (61) is provided with a mounting hole (611) for mounting the test tube body (1), the test tube body (1) is inserted into the mounting hole (611), and the test tube body (1) and the test base (61) are connected by welding.

8. The modal testing system according to claim 6, characterized in that: A receiving groove (621) is provided on one side of the test positioning seat (62) facing the test base (61), and the test tube body (1) is at least partially located in the receiving groove (621).

9. The modal testing system according to claim 8, characterized in that: The containing tank (621) is filled with a medium.

10. The modal testing system according to claim 9, characterized in that: The medium is high-temperature liquid metal or liquid water.

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