Steel plate longitudinal negative stiffness measuring device

Abstract

The utility model discloses a longitudinal negative stiffness measuring device for a steel plate, belongs to the technical field of measuring devices, and solves the problems that in the prior art, when the longitudinal negative stiffness of the steel plate is measured, the steel plate is easy to deform or break excessively, a sample is easy to damage, and equipment operation or personnel are easy to be injured. The steel plate clamping device comprises a base, a clamp arranged on the base and used for clamping a steel plate, a pressure applying structure arranged on the base or the clamp and used for applying pressure to the steel plate clamped on the clamp, and a limiting structure arranged on the base and used for limiting the moving distance of the steel plate. The limiting structure comprises a longitudinal supporting piece and a stress limiting plate arranged on the longitudinal supporting piece. The device is used for measuring the longitudinal negative stiffness of the steel plate.

Description

Technical Field

[0001] A longitudinal negative stiffness measuring device for steel plates, which is used for measuring the longitudinal negative stiffness of steel plates and belongs to the technical field of measuring devices. Background Art

[0002] Longitudinal negative stiffness refers to the non - typical characteristic of the ability of a steel plate to resist deformation when it is longitudinally compressed. That is, as the external force increases, the steel plate shows the phenomenon that the displacement direction is opposite to the external force direction within a certain range.

[0003] The negative stiffness characteristic can be used in the specific structural design of aerospace vehicles, especially in occasions where vibration reduction, vibration isolation or adaptive structural deformation is required. For example, a structure that can adaptively adjust its shape when subjected to flight loads can be designed by using longitudinally negatively stiff steel plates to improve the dynamic performance and structural stability of the aircraft.

[0004] In the design of aerospace vehicles, the use of longitudinal negative stiffness can, to a certain extent, improve the energy absorption capacity of the structure, reduce fatigue damage caused by vibration, and enhance the adaptability and safety of the aircraft in complex environments.

[0005] A longitudinal negative stiffness measuring device for steel plates is a device specifically used to test and evaluate the negative stiffness characteristics of steel plates under longitudinal loading conditions. This kind of device is usually used in fields such as aerospace, mechanical engineering and materials science to ensure that the performance of materials or structures meets the design requirements in specific applications.

[0006] However, the existing longitudinal negative stiffness measuring devices for steel plates have the following technical problems:

[0007] When measuring the longitudinal negative stiffness of a steel plate, the steel plate is prone to excessive deformation or fracture, which not only easily damages the specimen, but also easily causes problems in equipment operation or personal injury. Utility Model Content

[0008] The purpose of the present utility model is to provide a longitudinal negative stiffness measuring device for steel plates, which solves the problems that when measuring the longitudinal negative stiffness of a steel plate in the prior art, the steel plate is prone to excessive deformation or fracture, which not only easily damages the specimen, but also easily causes problems in equipment operation or personal injury.

[0009] In order to achieve the above purpose, the technical solution adopted by the present utility model is as follows:

[0010] A longitudinal negative stiffness measuring device for steel plates includes a base, a clamp provided on the base for clamping the steel plate, a pressing structure provided on the base or the clamp for applying pressure to the steel plate clamped on the clamp, and a limiting structure provided on the base for restricting the moving distance of the steel plate;

[0011] The limiting structure includes a longitudinal support member and a force - receiving limiting plate provided on the longitudinal support member.

[0012] Further, a groove is provided on the force-bearing limit plate, a flexible sensor is provided at the bottom of the groove, and a transmitter connected to the flexible sensor. At one end of the top of the groove, a fixing plate is fixedly provided. A plurality of through holes are provided on the fixing plate, and a rod body is inserted through the through holes, with one end cooperating with the pressing structure and the other end cooperating with the flexible sensor. An elastic reset member is sleeved on the rod body on one side of the bottom of the fixing plate, with one end connected to the rod body and the other end connected to the fixing plate.

[0013] Further, the longitudinal support member is a telescopic member.

[0014] Further, the fixture includes two clamping members provided on the base;

[0015] The two clamping members respectively include clamping blocks provided on the base. U-shaped grooves with opposite openings and used for fixing the steel plate are provided on the two clamping blocks;

[0016] The limiting structure is provided on the base between the two clamping blocks.

[0017] Further, the clamping blocks are slidably provided on the base; )]]

[0018] The fixture further includes a horizontal fixing member fixedly provided on the base;

[0019] The horizontal fixing member includes fixing blocks fixedly provided at both ends of the base, a bidirectional threaded rod and a positioning rod rotatably provided on the two fixing blocks, and a clamping block provided on the bidirectional threaded rod and the positioning rod for clamping or releasing the clamping block by rotating the bidirectional threaded rod.

[0020] Further, the clamping blocks on the same side are fixedly connected.

[0021] Further, a threaded member for fixing the steel plate is provided on the clamping block and inserted through the U-shaped groove;

[0022] Threaded holes are provided on the clamping blocks.

[0023] Further, the pressing structure includes an inverted U-shaped member provided on the base or the fixing block, a through hole provided on the inverted U-shaped member, and a pressing member inserted through the through hole for pressing the steel plate.

[0024] Further, the pressing member is a T-shaped pressing member, an inverted T-shaped pressing member or an I-shaped pressing member.

[0025] Further, mounting holes are provided at both ends of the base.

[0026] Compared with the prior art, the advantages of the present utility model are as follows:

[0027] 1. This utility model clamps a steel plate on a fixture and applies pressure to the steel plate by applying pressure to the pressing structure. When the steel plate may reach the limit of fracture or deformation, the movement distance of the steel plate is restricted by the force-bearing limit plate in the limiting structure, which can prevent excessive deformation or fracture, thereby protecting the specimen from damage and effectively avoiding damage to the equipment caused by the flying fragments of the broken steel plate or injury to personnel.

[0028] 2. This utility model sets a pressure sensing structure on the force-bearing limit plate. That is, when the steel plate may reach the limit of fracture or deformation, the flexible sensor is conducted by pressing the rod body, and a signal is transmitted through the transmitter, so as to control the pressing structure to stop applying pressure to the steel plate, effectively prevent the pressing structure from applying pressure to the force-bearing limit plate, and can also cooperate with the pressure sensing structure to achieve double limiting.

[0029] 3. This utility model defines the longitudinal support member as a telescopic member, aiming to facilitate telescopic adjustment according to different test requirements, so as to adapt to steel plates of different thicknesses and lengths.

[0030] 4. This utility model sets two clamping members on the base and clamps the steel plate through the U-shaped groove of the clamping block in the clamping member. It can not only effectively fix the steel plate and ensure its stability during the force-bearing process, but also facilitate quickly inserting the steel bar into the U-shaped groove through the side of the U-shaped groove for fixation.

[0031] 5. This utility model slides the clamping block in the clamping member on the base, which is convenient for clamping and releasing steel plates of different sizes. By rotating the bidirectional threaded rod, the two clamping blocks approach or move away from each other on the bidirectional threaded rod and the positioning rod, so that the operator can precisely control the clamping block to control the position of the clamping block, thereby ensuring the precise positioning and fixation of the steel plate during the force-bearing process.

[0032] 6. This utility model defines that the clamping blocks on the same side are fixedly connected to the clamping member, aiming to prevent the problem that the clamping member slides freely under the influence of external factors.

[0033] 7. The purpose of setting the threaded member on the clamping block of this utility model is to facilitate longitudinal fixation of steel plates of different thicknesses, so as to achieve stable fixation of the steel plate and ensure that it does not shift during the force-bearing process.

[0034] 8. The perforation on the inverted U-shaped member of the pressing structure in this utility model can ensure that the pressing member can apply uniform pressure to the steel plate and will not fall off, etc. Description of the Drawings

[0035] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following accompanying drawings only show certain embodiments of the present utility model, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related accompanying drawings can also be obtained based on these drawings.

[0036] Figure 1 is the structural schematic diagram of the present utility model;

[0037] Figure 2 is the structural schematic diagram of the base in the present utility model;

[0038] Figure 3 is the structural schematic diagram of the limiting structure in the present utility model;

[0039] Figure 4 is Figure 3 a partial cross-sectional view of;

[0040] Figure 5 is the structural schematic diagram of the fixture in the present utility model;

[0041] Figure 6 is the structural schematic diagram of the pressure-applying structure in the present utility model;

[0042] In the figure: 1 - base, 2 - fixture, 3 - pressure-applying structure, 4 - limiting structure, 5 - longitudinal support member, 6 - force-limiting plate, 7 - groove, 8 - flexible sensor, 9 - transmitter, 10 - fixing plate, 11 - through hole, 12 - rod body, 13 - elastic reset member, 14 - clamping block, 15 - U-shaped groove, 16 - fixing block, 17 - bidirectional threaded rod, 18 - positioning rod, 19 - threaded member, 20 - inverted U-shaped member, 21 - perforation, 22 - pressing member, 23 - mounting hole, 24 - clamping block. Specific embodiments

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following accompanying drawings. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0045] In the description of the present utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is customarily placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present utility model.

[0046] In addition, if terms such as "first", "second", "third", etc. are used only for distinguishing descriptions, they cannot be understood as indicating or implying relative importance.

[0047] In addition, if terms such as "horizontal", "vertical", "suspended", etc. are used, it does not mean that the component is required to be absolutely horizontal or suspended, but it can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal compared to "vertical", and it does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0048] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "install", "connect", "couple", etc. are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. 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 specific situations.

[0049] It should be noted that, without conflict, the features in the embodiments of the present utility model can be combined with each other.

[0050] In this case, for the components that need to bear force, the selected materials all meet the expected load and environmental conditions.

[0051] Embodiment 1

[0052] The longitudinal negative stiffness measurement is not merely for measuring the limit where the steel plate may break or deform, but for evaluating the overall mechanical properties of the steel plate when subjected to longitudinal compressive force, including its stiffness, buckling behavior, and possible negative stiffness characteristics. However, there is indeed a risk of the steel plate breaking or deforming during the longitudinal negative stiffness measurement. To solve the problems in the prior art that when measuring the longitudinal negative stiffness of the steel plate, the steel plate is prone to excessive deformation or fracture, which not only easily damages the specimen but also easily causes equipment operation or personal injury. For example Figures 1-4As shown, a longitudinal negative stiffness measuring device for steel plates is provided, including a base 1, a fixture 2 arranged on the base 1 for clamping the steel plate, a pressing structure 3 arranged on the base 1 or the fixture 2 for applying pressure to the steel plate clamped on the fixture 2, and a limiting structure 4 arranged on the base 1 for limiting the moving distance of the steel plate; the limiting structure 4 includes a longitudinal support member 5 and a force-bearing limiting plate 6 arranged on the longitudinal support member 5. In practice, it is necessary to first understand the basic mechanical behavior and possible buckling load of the steel plate to facilitate setting the limiting structure 4 for limiting. Mounting holes 23 are provided at both ends of the base 1, which is convenient for fixing during testing.

[0053] In practice, this device can be directly used to measure the longitudinal negative stiffness of steel plates. Specifically, fix the base 1, then clamp the steel plate to be measured on the fixture 2. After clamping, limit the moving distance of the steel plate through the limiting structure 4. At this time, apply pressure to the pressing structure 3 manually. The pressing structure 3 applies pressure to the steel plate for longitudinal negative stiffness measurement. The measurement result can be obtained from the distance between the pressure applied to the steel plate and the displacement. Of course, in practice, this device can also be installed on a universal testing machine to replace the fixture 2 and the pressing structure 3 on the existing universal testing machine. When measuring the longitudinal negative stiffness of the steel plate, the measurement result can be directly obtained through the universal testing machine.

[0054] In this embodiment, the steel plate is clamped on the fixture and pressure is applied to the pressing structure to press the steel plate. When the steel plate reaches the limit of fracture or deformation, the moving distance of the steel plate is restricted by the force-bearing limiting plate in the limiting structure, which can prevent excessive deformation or fracture, thereby protecting the specimen from damage and effectively avoiding the flying of steel plate fracture fragments from damaging the equipment or causing injury to personnel.

[0055] Embodiment 2

[0056] Based on Embodiment 1, a groove 7 is provided on the force-bearing limiting plate 6. A flexible sensor 8 is arranged at the bottom of the groove 7, and a transmitter 9 (which can be electromagnetically powered or externally powered) connected to the flexible sensor 8. One end of the top of the groove 7 is fixedly provided with a fixing plate 10. A plurality of through holes 11 are provided on the fixing plate 10. A rod 12 is passed through the through holes 11, with one end cooperating with the pressing structure 3 and the other end cooperating with the flexible sensor 8. An elastic reset member 13 is sleeved on the rod 12 on one side of the bottom of the fixing plate 10, with one end connected to the rod 12 and the other end connected to the fixing plate 10. The purpose of setting a plurality of through holes is to facilitate the setting of a plurality of rods, etc., which is conducive to pressing the flexible sensor 8 to conduct through at least one rod, avoiding the problem that when only one is set, it is easy to have deviation and cause the pressing structure to be unable to press the rod.

[0057] In practice, the base 1 is fixed, and then the steel plate to be measured is clamped on the fixture 2. After clamping, the moving distance of the steel plate is limited by the limiting structure 4. At this time, pressure is applied to the pressure application structure 3 manually, and the pressure application structure 3 applies pressure to the steel plate for longitudinal negative stiffness measurement. When the steel plate reaches the limit of possible fracture or deformation, the flexible sensor is turned on by pressing the rod body, and a signal is transmitted through the transmitter, so as to control the pressure application structure to stop applying pressure to the steel plate, effectively prevent the pressure application structure from applying pressure to the force-limiting plate, and can also cooperate with the pressure sensing structure to achieve double limiting.

[0058] Embodiment 3

[0059] On the basis of Embodiment 1, the longitudinal support member 5 is a telescopic member, such as a hydraulic telescopic mechanism or other telescopic structures. Defining the longitudinal support member as a telescopic member is to facilitate telescopic adjustment according to different test requirements, so as to adapt to steel plates of different thicknesses and lengths.

[0060] Embodiment 4

[0061] On the basis of Embodiment 3, the fixture 2 includes two clamping members arranged on the base 1; the two clamping members respectively include clamping blocks 14 arranged on the base, and U-shaped grooves 15 with opposite openings and used for fixing the steel plate are arranged on the two clamping blocks 14; the limiting structure 4 is arranged on the base 1 between the two clamping blocks 14.

[0062] In practice, in this case, the two clamping blocks 14 can be fixedly connected or movably connected to the base (such as fixed connection by bolts). When the fixture 2 clamps the steel plate, if the two clamping blocks 14 are fixedly connected to the base, the steel plate is directly inserted into the two U-shaped grooves 15 through the sides of the two U-shaped grooves 15 for fixation. If the two clamping blocks 14 are movably connected to the base, the steel plate can be inserted into the two U-shaped grooves 15 through the sides of the two U-shaped grooves 15 for fixation, or can be inserted into the two U-shaped grooves 15 through the opposite sides of the two U-shaped grooves 15 for fixation. In this embodiment, two clamping members are arranged on the base, and the steel plate is clamped by the U-shaped grooves of the clamping blocks in the clamping members, which can not only effectively fix the steel plate and ensure its stability during the force application process, but also facilitate the rapid insertion of the steel bar into the U-shaped groove through the side of the U-shaped groove for fixation.

[0063] Embodiment 5

[0064] On the basis of Embodiment 4, the clamping block 14 is slidably arranged on the base 1; the fixture 2 further includes a horizontal fixing member fixedly arranged on the base; the horizontal fixing member includes fixing blocks 16 fixedly arranged at both ends of the base 1, a bidirectional threaded rod 17 and a positioning rod 18 rotatably arranged on the two fixing blocks 16, and a clamping block 24 arranged on the bidirectional threaded rod 17 and the positioning rod 18 to clamp or release the clamping block 14 by rotating the bidirectional threaded rod 17. Among them, the bidirectional threaded rod 17 and the positioning rod 18 are rotatably connected to the fixing block 16 through bearings, or concave holes can be arranged on the fixing block 16 to rotatably connect with the bidirectional threaded rod 17 and the positioning rod 18.

[0065] In practice, by rotating the bidirectional threaded rod 17 to drive the two clamping blocks 24 to move away from each other, the steel plate is placed on the U-shaped groove 15 of the two clamping blocks 14, and then by rotating the bidirectional threaded rod 17 in the reverse direction, the two clamping blocks 24 are moved closer to clamp the clamping block 14 to fix the steel plate. In this embodiment, the clamping block in the clamping member is slidably arranged on the base, which is convenient for clamping and releasing steel plates of different sizes, and by rotating the bidirectional threaded rod to drive the two clamping blocks to move closer or farther away on the bidirectional threaded rod and the positioning rod, it is convenient for the operator to precisely control the clamping block to control the position of the clamping block, so as to ensure the precise positioning and fixation of the steel plate during the force application process.

[0066] Embodiment 6

[0067] On the basis of Embodiment 5, the clamping block 24 on the same side is fixedly connected to the clamping block 14. Limiting the fixed connection of the clamping block on the same side to the clamping block aims to prevent the problem that the clamping block slides freely under the influence of external factors. Of course, in practice, they may not be fixedly connected.

[0068] Embodiment 7

[0069] On the basis of Embodiment 6, a threaded member 19, such as a screw rod, a T-shaped bolt or an I-shaped screw rod, for fixing the steel plate is arranged on the clamping block 14 and penetrates through the U-shaped groove 15; a threaded hole is arranged on the clamping block 14 to cooperate with the threaded member 19. The purpose of arranging the threaded member on the clamping block is to facilitate the longitudinal fixation of steel plates of different thicknesses to achieve the stable fixation of the steel plate and ensure that it will not shift during the force application process.

[0070] Embodiment 8

[0071] On the basis of Embodiment 7, the pressing structure 3 includes an inverted U-shaped member 20 arranged on the base 1 or the fixing block 16, a through hole 21 arranged on the inverted U-shaped member, and a pressing member 22 penetrating through the through hole 21 to press the steel plate. The pressing member 22 is a T-shaped pressing member, an inverted T-shaped pressing member or an I-shaped pressing member. The through hole on the inverted U-shaped member of the pressing structure can ensure that the pressing member can apply uniform pressure to the steel plate and will not fall off, etc.

Claims

1. A device for measuring longitudinal negative stiffness of a steel plate, characterized by: The invention comprises a base (1), a clamp (2) arranged on the base (1) for clamping a steel plate, a pressure structure (3) arranged on the base (1) or the clamp (2) for applying pressure to the steel plate clamped by the clamp (2), and a limiting structure (4) arranged on the base (1) for limiting the moving distance of the steel plate; The limiting structure (4) comprises a longitudinal support member (5) and a force-bearing limiting plate (6) arranged on the longitudinal support member (5); The force limiting plate (6) is provided with a groove (7), a flexible sensor (8) and a transmitter (9) connected to the flexible sensor (8) are provided at the bottom of the groove (7), a fixing plate (10) is fixedly provided at one end of the top of the groove (7), a plurality of through holes (11) are provided on the fixing plate (10), a rod body (12) is passed through the through hole (11), one end of which cooperates with the pressure structure (3) and the other end cooperates with the flexible sensor (8), and an elastic reset member (13) is sleeved on the rod body (12) located on one side of the bottom of the fixing plate (10), one end of which is connected to the rod body (12) and the other end is connected to the fixing plate (10).

2. The device for measuring longitudinal negative stiffness of a steel plate according to claim 1, characterized in that: The longitudinal supporting member (5) is a telescopic member.

3. The device for measuring longitudinal negative stiffness of a steel plate according to claim 1, characterized in that: The clamp (2) comprises two clamping members arranged on the base (1); The two clamping members respectively include a clamping block (14) arranged on the base, and the two clamping blocks (14) are provided with U-shaped grooves (15) with openings facing each other and used for fixing the steel plate; The limiting structure (4) is arranged on the base (1) between the two clamping blocks (14).

4. The device for measuring longitudinal negative stiffness of a steel plate according to claim 3, characterized in that: The clamping block (14) is slidably arranged on the base (1); The clamp (2) further comprises a horizontal fixing member fixedly arranged on the base; The horizontal fixing member comprises a fixing block (16) fixedly arranged on both ends of the base (1), a bidirectional threaded rod (17) and a positioning rod (18) rotatably arranged on the two fixing blocks (16), and a clamping block (24) arranged on the bidirectional threaded rod (17) and the positioning rod (18) for clamping or releasing the clamping block (14) by rotating the bidirectional threaded rod (17).

5. The device for measuring longitudinal negative stiffness of a steel plate according to claim 4, characterized in that: The clamping block (24) on the same side is fixedly connected to the clamping block (14).

6. The device for measuring longitudinal negative stiffness of a steel plate according to claim 5, characterized in that: The clamping block (14) is provided with a screw member (19) which penetrates the U-shaped groove (15) and fixes the steel plate; The clamping block (14) is provided with a threaded hole matched with the threaded member (19).

7. The device for measuring longitudinal negative stiffness of a steel plate according to claim 6, characterized in that: The pressure structure (3) comprises an inverted U-shaped member (20) arranged on the base (1) or the fixed block (16), a through hole (21) arranged on the inverted U-shaped member, and a pressing member (22) arranged through the through hole (21) to press the steel plate.

8. The device for measuring longitudinal negative stiffness of a steel plate according to claim 7, characterized in that: The pressing piece (22) is a T-shaped pressing piece, an inverted T-shaped pressing piece or an I-shaped pressing piece.

9. The device for measuring longitudinal negative stiffness of a steel plate according to claim 1, characterized in that: Mounting holes (23) are provided on both ends of the base (1).

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