Pneumatic loading structure tester

Abstract

The application discloses a kind of air pressure loading structure testing machines, the air pressure loading structure testing machine includes counterforce frame, loading plate and expansion component, counterforce frame includes counterforce beam and support part, counterforce beam is arranged on support part, loading plate is arranged on support part and is oppositely arranged with counterforce beam along the extension direction of support part to form first cavity, the side of loading plate away from counterforce beam forms second cavity with counterforce frame, loading plate is movable along the length direction of counterforce frame relative to counterforce frame, or loading plate is rotatable around the width direction of counterforce frame relative to counterforce frame, expansion component is arranged in at least one of first cavity and second cavity, second cavity is suitable for installing test piece and test piece is in abutment with loading plate, expansion component is suitable for being passed into expansion medium to adjust the force of loading plate to test piece, the stiffness and damping of expansion component are less than the stiffness and damping of test piece.The air pressure loading structure testing machine of the application has the advantages of simple structure, small vibration, low noise and the like.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering structural testing technology, and particularly relates to a pneumatic loading structural testing machine. Background Technology

[0002] The mechanical properties of some structural components are affected by the magnitude of external pressure. For example, the vertical stiffness of rubber bearings usually increases with the increase of vertical pressure. Therefore, when testing the mechanical properties of structural components, the pressure on the specimen should be consistent with the actual use conditions in engineering.

[0003] In related technologies, testing machines cannot simulate the actual boundary conditions of structural specimens in engineering applications, resulting in large testing errors. Summary of the Invention

[0004] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0005] In related technologies, for bearing components such as seismic isolation bearings, the structure above the bearing in actual engineering can be considered as a mass body unconstrained by external displacement. The superstructure only provides pressure to the bearing without constraining its vertical deformation. Traditional structural testing machines in civil engineering apply external forces to the specimen using hydraulic or electromagnetic actuators to simulate the stress conditions of the specimen. However, due to the high stiffness of the actuators, the vertical vibration of the bearing is constrained during the bearing compression test, which does not conform to the actual situation in engineering where the bearing is only under compression and not constrained by vertical displacement. Electromagnetic and hydraulic actuators have high damping, which causes the free vibration of the structural specimen in contact with the actuator to decay rapidly. Furthermore, the vibration noise generated by general structural testing machines during operation is relatively large, which is not conducive to collecting the vibration signal of the specimen and makes it impossible to use the transfer function method to measure the dynamic characteristics of the bearing specimen under compression.

[0006] It is evident that hydraulic loading structural testing machines cannot simulate the actual boundary conditions of structural specimens in engineering applications when determining their dynamic characteristics. Therefore, there is an urgent need for a structural testing machine capable of applying controllable pressure to the specimen while simultaneously imposing minimal vertical displacement constraints and damping.

[0007] The present invention aims to at least partially solve one of the technical problems in the related art.

[0008] Therefore, embodiments of the present invention propose a pneumatic loading structure testing machine that is simple in structure, accurate in detection, and has small error.

[0009] A pneumatic loading structure testing machine according to an embodiment of the present invention includes: a reaction frame, the reaction frame including a reaction beam and a support portion, the reaction beam being disposed on the support portion; a loading plate, the loading plate being disposed on the support portion and spaced apart from the reaction beam along the extension direction of the support portion to form a first cavity, the side of the loading plate away from the reaction beam forming a second cavity with the reaction frame, the loading plate being movable relative to the reaction frame along the length direction of the reaction frame, or the loading plate being rotatable relative to the reaction frame about the width direction of the reaction frame; an expansion assembly, the expansion assembly being disposed in at least one of the first cavity and the second cavity, the second cavity being adapted to install a specimen and the specimen abutting against the loading plate, the expansion assembly being adapted to introduce an expansion medium to adjust the force exerted by the loading plate on the specimen, the stiffness and damping of the expansion assembly being less than the stiffness and damping of the specimen.

[0010] The pneumatic loading structure testing machine of this invention is equipped with an expansion component, which can avoid the pneumatic loading structure testing machine from affecting the free vibration of the specimen during the loading process. Moreover, the expansion component can still maintain pressure naturally after expansion, without the need for a complex power system to make constant adjustments. This reduces the vibration noise of the loading device itself and improves the accuracy of the test results.

[0011] In some embodiments, the pneumatic loading structural testing machine further includes a first detection component disposed within the second cavity and located between the specimen and the loading plate, the first detection component being used to detect the force exerted by the loading plate on the specimen, and / or, the pneumatic loading structural testing machine further includes a second detection component located within the second cavity and on the side of the specimen away from the loading plate, the second detection component being used to detect the force exerted by the loading plate on the specimen.

[0012] In some embodiments, the expansion assembly includes a plurality of expansion units, which are sequentially disposed in the first cavity or the second cavity along the circumference of the first cavity. The expansion assembly has a first state and a second state. In the first state, the expansion medium introduced into two adjacent expansion units is the same. In the second state, the expansion medium introduced into two adjacent expansion units is different.

[0013] In some embodiments, the pneumatic loading structural testing machine further includes a vibration assembly disposed in the second cavity on the side of the specimen away from the loading plate, and the vibration assembly can emit vibration signals to drive the specimen to vibrate.

[0014] In some embodiments, the pneumatic loading structure testing machine further includes: a third detection component disposed within the loading plate, the third detection component being used to detect vibration signals on one side of the specimen; and a fourth detection component disposed within the second cavity and located on the side of the specimen away from the loading plate, the fourth detection component being used to detect vibration signals on the other side of the specimen.

[0015] In some embodiments, the reaction beam is movable relative to the support and along the extension direction of the support. The pneumatic loading structure testing machine further includes a positioning member, which is detachably connected to the support and the reaction beam, so that the reaction beam can be adjusted on the support along the height direction of the reaction frame via the positioning member.

[0016] In some embodiments, the length direction of the reaction frame is vertical, the first cavity is located above the second cavity, the expansion assembly is disposed in the first cavity and the upper and lower sides of the expansion assembly are connected to the reaction beam and the loading plate, so that the expansion assembly expands to adjust the pressure on the specimen. The expansion assembly is in a first state, and the amount of expansion medium introduced into the two adjacent expansion units is the same, so as to uniformly apply pressure to the loading plate.

[0017] In some embodiments, the length direction of the reaction frame is vertical, the first cavity is located above the second cavity, the expansion assembly is disposed in the second cavity and connected to the loading plate, and the loading plate is connected to the specimen so that the expansion assembly expands to adjust the tension on the specimen. The expansion assembly is in a first state, and the amount of expansion medium introduced into two adjacent expansion units is the same, so as to uniformly apply pressure to the loading plate.

[0018] In some embodiments, the reaction frame is horizontal in length, and the first and second cavities are arranged sequentially in the horizontal direction. The pneumatic loading structure testing machine further includes a crossbeam extending along the length of the reaction frame. The crossbeam is disposed in the second cavity and connected to the loading plate. The expansion assembly is disposed in the first cavity and connected to the reaction beam and the loading plate, so that the loading plate can move the crossbeam along the length of the reaction frame. The specimen is disposed between the bottom of the crossbeam and the support, and the upper end of the specimen is connected to the bottom surface of the crossbeam, so that the loading plate applies shear force to the specimen through the crossbeam. The expansion assembly is in a first state, and the amount of expansion medium introduced into two adjacent expansion units is the same, so as to apply pressure to the loading plate uniformly.

[0019] In some embodiments, the pneumatic loading structure testing machine further includes a rotating shaft, which passes through the loading plate and is rotatably disposed within the reaction frame. The expansion assembly includes a first expansion unit, a second expansion unit, a third expansion unit, and a fourth expansion unit. The first expansion unit and the second expansion unit are both disposed within the reaction frame. The first expansion unit and the second expansion unit are both disposed within the first cavity and are spaced apart along the length direction of the reaction frame. The rotating shaft is located between the first expansion unit and the second expansion unit. The specimen and the rotating shaft are disposed opposite to each other in the width direction of the reaction frame. The third expansion unit and the fourth expansion unit are disposed within the second cavity. The third expansion unit and the first expansion unit are disposed opposite to each other in the width direction of the reaction frame. The fourth expansion unit and the second expansion unit are disposed opposite to each other in the width direction of the reaction frame. The specimen is disposed between the third expansion unit and the fourth expansion unit. The expansion assembly is in a second state, and the amount of expansion medium introduced into the two expansion units in the same cavity is different. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the pneumatic loading structure testing machine according to the first embodiment of the present invention.

[0021] Figure 2 This is provided by the embodiments of the present invention. Figure 1 A cross-sectional view of section 1-1.

[0022] Figure 3 This is provided by the embodiments of the present invention. Figure 1 Schematic diagram of the cross-sectional structure of section 2-2.

[0023] Figure 4 This is provided by the embodiments of the present invention. Figure 1 A cross-sectional view of section 3-3.

[0024] Figure 5 This is provided by the embodiments of the present invention. Figure 1 Schematic diagram of the cross-sectional structure of section 4-4.

[0025] Figure 6 This is provided by the embodiments of the present invention. Figure 1 A cross-sectional view of section 5-5.

[0026] Figure 7 This is a schematic diagram of the installation of the first and third detection components of the pneumatic loading structure testing machine according to the first embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the installation of the second and fourth detection components of the pneumatic loading structure testing machine according to the first embodiment of the present invention.

[0028] Figure 9 This is a schematic diagram of the installation of the vibration component of the pneumatic loading structure testing machine according to the first embodiment of the present invention.

[0029] Figure 10 This is a side view of the pneumatic loading structure testing machine according to the first embodiment of the present invention.

[0030] Figure 11 This is a schematic diagram of the structure of the pneumatic loading structure testing machine according to the second embodiment of the present invention.

[0031] Figure 12 This is a schematic diagram of the structure of the pneumatic loading structure testing machine according to the third embodiment of the present invention.

[0032] Figure 13 This is a cross-sectional view of the pneumatic loading structure testing machine according to the third embodiment of the present invention.

[0033] Figure 14 This is a schematic diagram of the structure of the pneumatic loading structure testing machine according to the fourth embodiment of the present invention.

[0034] Figure 15 This is a schematic diagram of the expansion component of the pneumatic loading structure testing machine according to an embodiment of the present invention.

[0035] 100 air pressure loading structural testing machine;

[0036] Reaction frame 1; reaction beam 11; main reaction beam 111; secondary reaction beam 112; support section 12; support rod 121; first cavity 122; second cavity 123; base plate 13;

[0037] Loading plate 2; Limiting wheel 21;

[0038] Expansion assembly 3; First expansion unit 31; Second expansion unit 32; Third expansion unit 33; Fourth expansion unit 34; Connecting plate 35

[0039] First detection component 4; Second detection component 5;

[0040] Vibration component 6;

[0041] Third testing component 7; Fourth testing component 8; Crossbeam 9; Rotating shaft 10; First lifting ring 101; Second lifting ring 102; Specimen 103. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] The pneumatic loading structure testing machine according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0044] like Figure 1-15 As shown, the pneumatic loading structure testing machine 100 according to an embodiment of the present invention includes a reaction frame 1, a loading plate 2, and an expansion assembly 3.

[0045] The reaction frame 1 includes a reaction beam 11 and a support portion 12, with the reaction beam 11 mounted on the support portion 12. Specifically, as shown... Figure 1-2 As shown, the support part 12 includes a plurality of rigid support rods 121. The support rods 121 are spaced apart in the left-right or front-back direction to form a support frame and surround a loading space within the support part 12. A reaction beam 11 is installed on a horizontal surface at a certain height within the loading space. The reaction beam 11 is rigid and fixedly installed within the support part 12.

[0046] The loading plate 2 is disposed on the support portion 12 and is spaced apart from the reaction beam 11 along the extending direction of the support portion 12 to form a first cavity 122. The side of the loading plate 2 away from the reaction beam 11 forms a second cavity 123 with the reaction frame 1. That is, the support portion 12 is divided into the first cavity 122 and the second cavity 123 by the loading plate 2. The loading plate 2 is movable relative to the reaction frame 1 along the length direction of the reaction frame 1, or the loading plate 2 is rotatable relative to the reaction frame 1 about an axis perpendicular to the length direction of the reaction frame 1. Specifically, as shown... Figure 1-15 As shown, loading plate 2 can be configured according to actual conditions, for example: Figure 1 and Figure 11 As shown, when the reaction frame 1 is installed vertically on the ground, that is, the length direction of the reaction frame 1 is vertical, the loading plate 2 is a horizontal plate and divides the support part 12 into a first cavity 122 and a second cavity 123 arranged in the vertical direction, as follows: Figure 12 and Figure 14 As shown, when the reaction frame 1 is horizontally installed on the bottom surface, that is, the length direction of the reaction frame 1 is horizontal, the loading plate 2 is a vertical plate and the support part 12 is divided into a first cavity 122 and a second cavity 123 arranged in the left and right directions. The loading plate 2 can move in the up and down direction or the left and right direction, or can rotate around the front and back direction, according to the test requirements.

[0047] The expansion assembly 3 is disposed in at least one of the first cavity 122 and the second cavity 123. The second cavity 123 is adapted to install the specimen 103, and the specimen 103 abuts against the loading plate 2. The expansion assembly 3 is adapted to be filled with an expansion medium to adjust the force exerted by the loading plate 2 on the specimen 103. The stiffness and damping of the expansion assembly 3 are both less than the stiffness and damping of the specimen 103. Specifically, as shown... Figure 1-15 As shown, the expansion component 3 can be an air cushion and can be filled with high-pressure gas. The expansion component 3 can be set in the first cavity 122 and the second cavity 123 according to the actual situation, for example: Figure 1As shown, when it is necessary to measure the pressure of the specimen 103, the expansion assembly 3 can be placed in the first cavity 122, so that when the expansion assembly 3 expands, it pushes the loading plate 2 toward the adjacent specimen 103, so as to apply pressure to the specimen 103 through the loading plate 2. Figure 11 As shown, when it is necessary to test the tensile force of the specimen 103, the expansion component 3 needs to be placed in the second cavity 123 so that when the expansion component 3 expands, it pushes the loading plate 2 to move away from the specimen 103, so as to apply tensile force to the specimen 103 through the loading plate 2.

[0048] The pneumatic loading structural testing machine 100 of this invention includes a loading plate 2 and an expansion component 3. The expansion component 3 loads the specimen 103 through the loading plate 2. Since the stiffness of the expansion component 3 is much smaller than that of the structural specimen 103 and the damping of the expansion component 3 itself is small, the expansion component 3 avoids affecting the free vibration of the specimen 103. Furthermore, the expansion component 3 can naturally maintain pressure for a period of time after expansion, without the need for a complex power system for constant adjustment. This results in the pneumatic loading structural testing machine 100 itself having virtually no vibration noise, thus effectively solving the problems in related technologies where structural testing machines cannot achieve high-pressure, low-constraint vertical compression loading, and where the testing machine causes significant interference to the vibration signal acquisition of the specimen 103, thereby improving the accuracy of the test.

[0049] In the pneumatic loading structural testing machine 100 of this invention, the force on the specimen 103 mainly comes from the pressure generated by the expansion component 3. After the pressurization is completed, the expansion component 3 naturally maintains the pressure, and the pneumatic loading structural testing machine 100 is in a static state with low vibration and noise. Since the expansion component 3 has low compressive stiffness and can apply sufficient pressure by filling with expansion medium, it can better simulate the working state of structural components such as supports in actual engineering where they are only subjected to vertical pressure and not constrained by upper displacement.

[0050] In some embodiments, the reaction beam 11 includes two main reaction beams 111 and multiple secondary reaction beams 112. The two ends of the main reaction beams 111 are respectively connected to two vertical support rods 121 by bolts. The two ends of each secondary reaction beam 112 are respectively connected to two main reaction beams 111. The bottom surfaces of the main reaction beams 111 and the secondary reaction beams 112 are on the same plane. The two ends of the main reaction beams 111 are respectively connected to two vertical support rods 121 by bolts. It can be understood that by selecting bolt holes at different heights for bolt connection, the reaction beams 11 can be arranged at different heights, changing the height of the loading space within the support 12, and flexibly adapting to the loading requirements of specimens 103 at different heights.

[0051] In some embodiments, the number of support parts 12 may be set differently according to the actual situation, and different structural arrangements may be adopted, such as setting column feet for the vertical support parts 12.

[0052] In some embodiments, the loading plate 2 is composed of two upper and lower steel plates and a certain number of vertical stiffening ribs. The loading plate 2 has a large rigidity so that its deformation under the action of air cushion pressure can be ignored. When the loading plate 2 moves or rotates, it transmits the pressure of the expansion component 3 to the specimen 103.

[0053] In some embodiments, the loading plate 2 adopts different structural arrangements to ensure rigidity, such as using a reinforced concrete slab. In addition, the loading plate 2 may also adopt different forms to restrict its rotation and displacement in the horizontal plane.

[0054] In some embodiments, the pneumatic loading structural testing machine 100 has two types: self-balancing configuration and non-self-balancing configuration.

[0055] In the self-balancing configuration, the bottom of the reaction frame 1 has a base plate 13, which is connected to the bottom of the support part 12. The base plate 13, the support part 12, and the reaction beam 11 surround and form a loading space within the support part 12. The base plate 13 and the reaction frame 1 are spaced apart to define the second cavity 123. In the self-balancing configuration, the pressure of the specimen 103 acts downward on the base plate 13. In other words, in the self-balancing configuration, the pressure of the specimen 103 acts downward on the interior of the reaction frame 1.

[0056] In the non-self-balancing configuration, the bottom of the support 12 is connected to the ground, and the ground and the reaction frame 1 are spaced apart to define the second cavity 123. The specimen 103 is placed on the ground within the loading space. In the non-self-balancing configuration, the pressure of the specimen 103 acts downward on the ground, i.e., outside the reaction frame 1.

[0057] In some embodiments, the reaction frame 1 is provided with four spaced-apart support rods 121 as vertical support parts 12, which surround and form a loading space. A reaction beam 11 is installed on a horizontal surface at a certain height in the loading space. The reaction beam 11 includes two main reaction beams 111 and several secondary reaction beams 112. The two ends of the main reaction beams 111 are respectively connected to the two vertical support parts 12 by bolts. The two ends of each secondary reaction beam 112 are respectively connected to the two main reaction beams 111, and the bottom surfaces of the main reaction beams 111 and the secondary reaction beams 112 are on the same plane.

[0058] In some embodiments, the pneumatic loading structure testing machine 100 further includes a first detection component 4, which is disposed within the second cavity 123 and located between the specimen 103 and the loading plate 2. The first detection component is used to detect the force exerted by the loading plate 2 on the specimen 103. Specifically, the first detection component 4 is an axial pressure sensor, which is disposed within the second cavity 123 and is located on the loading plate 2 between the loading plate 2 and the specimen 103. Thus, the first detection component 4 collects and outputs the vertical pressure load signal received by the loading plate 2, so that the actual pressure exerted by the expansion component 3 on the loading plate 2 can be accurately obtained in real time during the test, providing a reference for adjusting the air pressure of the expansion component 3.

[0059] In some embodiments, the pneumatic loading structural testing machine 100 further includes a second detection component 5, which is located within the second cavity 123 and on the side of the specimen 103 away from the loading plate 2. The second detection component 5 is used to detect the force exerted by the loading plate on the specimen 103. Specifically, the second detection component 5 is an axial pressure sensor. In a self-balancing configuration, the second detection component 5 is disposed on the base plate 13 and located between the specimen 103 and the base plate 13. In a non-self-balancing configuration, the second detection component 5 is disposed on the ground and located between the specimen 103 and the ground. The second detection component 5 is connected to the specimen 103 and can measure the vertical pressure load on the specimen 103.

[0060] In some embodiments, the pneumatic loading structural testing machine 100 further includes a vibration assembly 6, which is disposed within the second cavity 123 on the side of the specimen 103 away from the loading plate 2. The vibration assembly 6 can emit vibration signals to drive the specimen 103 to vibrate. Specifically, as Figure 9 As shown, the vibration component 6 is a vibration signal generator. In the self-balancing configuration, the vibration component 6 is set on the base plate 13 and located between the specimen 103 and the base plate 13. In the non-self-balancing configuration, the vibration component 6 is set on the ground and located between the specimen 103 and the ground. The vibration component 6 can generate vibration signals to test the dynamic characteristics of the structural specimen 103.

[0061] In some embodiments, the pneumatic loading structural testing machine 100 further includes a third detection component 7 and a fourth detection component 8.

[0062] The third detection component 7 is disposed within the loading plate 2, and is used to detect the vibration signal on one side of the test specimen 103. The fourth detection component 8 is disposed within the second cavity 123 and located on the side of the test specimen 103 away from the loading plate 2, and is used to detect the vibration signal on the other side of the test specimen 103. Specifically, as shown... Figure 7 and Figure 8As shown, both the third detection component 7 and the fourth detection component 8 are vibration signal acquisition devices. The third detection component 7 is mounted on the loading plate 2. In the self-balancing configuration, the fourth detection component 8 is mounted on the base plate 13 and located between the specimen 103 and the base plate 13. In the non-self-balancing configuration, the fourth detection component 8 is mounted on the ground and located between the specimen 103 and the ground. Thus, by detecting the vibration signals (e.g., vibration frequency, vibration intensity, etc.) on both sides of the specimen 103 using the third detection component 7 and the fourth detection component 8, the transfer function is obtained from the detected changes in the front and rear vibration waves of the specimen 103. The characteristic frequencies of the specimen 103 can then be analyzed, and the dynamic characteristics of the specimen 103 can be obtained based on the transfer function. Therefore, through the cooperation of the first detection component 4, the second detection component 5, the vibration component 6, the third detection component 7, and the fourth detection component 8, the free vibration or vertical vibration response of the specimen 103 under external excitation can be measured, and the dynamic performance of the structural specimen can be accurately measured.

[0063] It should be noted that multiple vibration components 6, the third detection component 7, and the fourth detection component 8 can be arranged, but usually at most one vibration component 6 generator is in working state at the same time to prevent multiple signal vibration sources from existing simultaneously, which would increase the difficulty of analysis. By simultaneously acquiring the vibration signals of the base plate 13 and the loading plate 2, the transfer function of the vibration signal in the specimen 103 can be analyzed, and then the characteristic frequency of the specimen 103 can be analyzed. In addition, by evenly arranging the third detection component 7 and the fourth detection component 8 at multiple points, the characteristics of the vibration signal can be obtained more accurately and completely. The fourth detection component 8 will acquire the vibration signal actually output by the vibration component 6 to avoid the error of the vibration component 6 and the possible changes in the vibration signal generation mechanism after the specimen 103 is installed.

[0064] In some embodiments, the reaction beam 11 is movable relative to and along the extending direction of the support portion 12. The pneumatic loading structure testing machine 100 also includes a positioning member, which is detachably connected to both the support portion 12 and the reaction beam 11, so that the reaction beam 11 can be adjusted along the height direction of the reaction frame 1 on the support portion 12 via the positioning member. Specifically, as Figure 1 As shown, the reaction beam 11 can be detachably mounted on the support 12 via a positioning member and can be moved in the vertical direction and positioned by the positioning member, thereby adjusting the position of the reaction beam 11 on the support 12.

[0065] The pneumatic loading structure testing machine 100 of this invention does not impose any restrictions on the support part 12. For example, an array of slots at different heights are arranged on the side of the support part 12 along the length direction, and the reaction beam 11 is fixed at different heights by the slots 122. Alternatively, the positioning element can be a screw or bolt, and the support part 12 and the reaction beam 11 are connected by screws or bolts, thereby adjusting the height of the reaction beam 11.

[0066] In some embodiments, the support portion 12 is provided with a slide rail extending along the extending direction of the support portion 12 on the side facing the loading plate 2, and the loading plate 2 is provided with a limiting wheel 21 that slides with the slide rail, so that the loading plate 2 can move along the extending direction of the support portion 12. Specifically, as Figure 1-13 As shown, each of the four support rods 121 has a slide rail 121 extending along its length on its inner side. A limiting wheel 21, which mates with the slide rail, is provided on the loading plate 2. The limiting wheel 21 is bolted to the loading plate 2 and its thickness matches the width of the slide rail. The limiting wheels 21 at the four corners of the loading plate 2 are respectively engaged in the slide rail. The limiting wheels 21 can move along the slide rail's vertical direction. Thus, the cooperation between the slide rail and the limiting wheel 21 forms a limiting device, preventing the loading plate 2 from translating or rotating relative to the width of the support portion while not obstructing its movement along the length of the support portion.

[0067] It is understandable that since the limiting wheel 21 is fixed to the loading plate 2 as a whole, and the limiting wheel 21 restricts the translation and rotation of the loading plate 2, it is only allowed to move relative to the length direction of the support member 121, thereby ensuring that the external force on the specimen 103 comes from the expansion component 3, and ensuring the safety of the pneumatic loading structure testing machine 100.

[0068] In some embodiments, the expansion assembly 3 includes a plurality of expansion units, which are sequentially disposed within the first cavity 122 or the second cavity 123 along the circumferential direction of the first cavity 122. The expansion assembly 3 has a first state and a second state. In the first state, the expansion medium introduced into two adjacent expansion units is the same; in the second state, the expansion medium introduced into two adjacent expansion units is different. Specifically, as shown... Figure 1-14 The expansion units can be set according to the actual situation. Multiple expansion units are evenly distributed in the first cavity 122 or the second cavity 123. For example, in the first state, the expansion medium introduced into the expansion units is the same so that the air pressure in each expansion unit is equal. In the second state, the expansion medium introduced into the expansion units is different so that the air pressure in the expansion units can be unequal. Thus, the expansion units can be adjusted according to the actual situation, thereby adjusting the force on the specimen 103.

[0069] In some embodiments, the expansion component 3 is spherical, and its top contacts the bottom of the reaction beam 11 when inflated. Depending on the shape of the air cushion, four connecting plates 35 are arranged at appropriate intervals on the upper surface of the loading plate 2. The connecting plates 35 can be connected to the expansion component 3 by adhesive bonding or fixed to the upper surface of the loading plate 2 by bolts. This arrangement allows for flexible assembly and disassembly of different air cushions according to loading requirements, facilitates air cushion maintenance, and ensures the versatility and safety of the device.

[0070] In some embodiments, such as Figure 15As shown, the expansion components 3 have different quantities and shapes to adapt to structural testing machines of different specifications. For example, the expansion components 3 can be spherical, cylindrical, square, or any other shape.

[0071] In some embodiments, the expansion assembly 3 and the loading plate 2 are connected and fixed in different ways, such as by a flange connection.

[0072] In some embodiments, the reaction beam 11 is equipped with a first lifting ring 101, and the side of the loading plate 2 is equipped with a second lifting ring 102 that cooperates with the first lifting ring 101. Slings are respectively threaded through the first lifting ring 101 and the second lifting ring 102. Thus, when no loading is applied, the slings can be used to lift the loading plate 2, preventing it from falling onto the base plate 13. This ensures a certain distance between the loading plate 2 and the base plate 13, providing sufficient operating space for placing the specimen 103 and removing it after the test, thus improving the ease of operation and safety of the testing machine. During loading, the slings are loosened so that the loading plate 2 only bears the driving force of the expansion assembly 3.

[0073] It should be noted that the length of the sling can be adjusted by devices such as the limit wheel 21. During the installation of the specimen 103, the sling can be shortened to pull up the loading plate 2. After the specimen 103 is installed, the sling can be extended to make the loading plate 2 fall and contact the top of the specimen 103. During the process of the loading plate 2 moving vertically downward until it contacts the specimen 103 and applies the set loading pressure, the sling has sufficient length and does not affect the vertical movement of the loading plate 2.

[0074] It is worth noting that different types of devices can be used to lift the loading plate 2, such as jacks, electric telescopic rods, cylinders, etc., placed under the loading plate 2 to lift it up.

[0075] In some embodiments, the reaction frame 1 is oriented vertically, the first cavity 122 is located above the second cavity 123, and the expansion assembly 3 is disposed within the first cavity 122, with its upper and lower sides connected to the reaction beam 11 and the loading plate 2, so that the expansion assembly 3 expands to adjust the pressure on the specimen 103. Specifically, as shown... Figure 1-10 As shown, the support portion 12 extends vertically, and the loading plate 2 is a horizontal plate that divides the support portion 12 vertically into a first cavity 122 and a second cavity 123. The first cavity 122 is the upper chamber, and the second cavity 123 is the lower chamber. The expansion assembly 3 includes four expansion units (such as...). Figure 3The four expansion units shown are evenly arranged in the first cavity 122, with the upper end of each expansion unit connected to the reaction beam 11 and the lower end of each expansion unit connected to the loading plate 2. The expansion assembly 3 is in the first state, that is, the amount of expansion medium introduced into the two adjacent expansion units is the same, and pressure is applied evenly to the loading plate 2, so that the expansion assembly 3 expands to drive the loading plate 2 to move downward, thereby increasing the pressure of the loading plate 2 on the specimen 103. Therefore, when measuring the mechanical properties of the specimen 103, the pressure on the specimen 103 should be consistent with the actual use state in engineering.

[0076] In some embodiments, the reaction frame 1 is oriented vertically, the first cavity 122 is located above the second cavity 123, the expansion assembly 3 is disposed within the second cavity 123 and connected to the loading plate 2, and the loading plate 2 is connected to the specimen 103 so that the expansion assembly 3 expands to adjust the tensile force on the specimen 103. Specifically, as shown... Figure 11 As shown, the support portion 12 extends vertically, and the loading plate 2 is a horizontal plate that divides the support portion 12 vertically into a first cavity 122 and a second cavity 123. The first cavity 122 is the upper chamber, and the second cavity 123 is the lower chamber. There are two expansion components 3 (e.g., Figure 11 As shown in the diagram, two expansion units are spaced apart in the second cavity 123 along the left-right direction, and the upper end of each expansion unit is connected to the loading plate 2 (e.g., by bonding, screw connection, etc.). The lower end of each expansion unit abuts against the base plate 13 (or the ground). The loading plate 2 is connected to the upper end of the specimen 103. The expansion assembly 3 is in the first state, that is, the amount of expansion medium introduced into the two expansion units is the same, and pressure is applied evenly to the loading plate 2, so that the expansion assembly 3 expands to drive the loading plate 2 to move upward, thereby causing the loading plate 2 to apply tension to the specimen 103. Therefore, when measuring the mechanical properties of the specimen 103, the tension on the specimen 103 should be consistent with the actual use state in engineering.

[0077] In some embodiments, the reaction frame 1 is horizontal in length, and the first cavity 122 and the second cavity 123 are arranged sequentially in the horizontal direction. The pneumatic loading structure testing machine 100 also includes a crossbeam 9 extending along the length of the reaction frame 1. The crossbeam 9 is disposed in the second cavity 123 and connected to the loading plate 2. The expansion assembly 3 is disposed in the first cavity 122 and connected to the reaction beam 11 and the loading plate 2, so that the loading plate 2 can move the crossbeam 9 along the length of the reaction frame 1. The specimen 103 is disposed between the bottom of the crossbeam 9 and the support 12. The axial direction of the specimen 103 is vertical, that is, the axial direction of the specimen 103 is perpendicular to the length of the reaction frame 1. The upper end of the specimen 103 is in contact with the crossbeam 9, so that the loading plate 2 applies shear force to the specimen 103 through the crossbeam 9. Specifically, as shown in the figure... Figure 12 and Figure 13As shown, the reaction frame 1 is placed horizontally on the ground and extends in the left-right direction. The loading plate 2 is a vertical plate and is located inside the support part 12, which is divided into a first cavity 122 and a second cavity 123 in the left-right direction. The first cavity 122 is located to the right of the second cavity 123. The crossbeam 9 extends in the left-right direction and its right end is connected to the left end of the loading plate 2. The expansion assembly 3 may include one or more expansion units. The multiple expansion units are connected sequentially in the left-right direction and are located in the first cavity 122. The left and right ends of the expansion assembly 3 are connected to the reaction beam 11 and the loading plate 2, respectively. The expansion assembly 3 is in the first state, and the amount of expansion medium introduced into two adjacent expansion units is the same. The loading plate 2 is uniformly pressured, causing the expansion assembly 3 to drive the loading plate 2 to move in the left and right directions, which in turn drives the crossbeam 9 to move in the left and right directions. The crossbeam 9 and the reaction frame 1 are spaced apart on the side near the ground so that the specimen 103 is placed on the side of the crossbeam 9 and the reaction frame 1 near the ground, and the upper end face of the specimen 103 is matched with the lower end face of the crossbeam 9. The axial direction of the specimen 103 is vertical. The horizontal thrust applied by the expansion assembly 3 is applied to the specimen 103 in the form of shear force through the loading plate 2 and the crossbeam 9. Therefore, when measuring the mechanical properties of the specimen 103, the shear force on the specimen 103 should be consistent with the actual use state in engineering. In this embodiment, the pneumatic loading test machine is a shear loading test machine.

[0078] In some embodiments, the pneumatic loading structure testing machine 100 further includes a rotating shaft 10, which passes through the loading plate 2 and is rotatably disposed within the reaction frame 1. Specifically, as shown... Figure 14 As shown, the rotating shaft 10 extends in the front-to-back direction and is located inside the reaction frame 1, at the upper end face of the reaction frame 1. The rotating shaft 10 passes through the middle of the loading plate 2. The loading plate 2 extends in the left-to-right direction, and the outer circumferential surface of the loading plate 2 is spaced apart from the inner circumferential surface of the reaction frame 1. Thus, the loading plate 2 rotates inside the reaction frame 1 through the rotating shaft 10.

[0079] In some embodiments, the expansion assembly 3 includes a first expansion unit 31, a second expansion unit 32, a third expansion unit 33, and a fourth expansion unit 34. The first expansion unit 31 and the second expansion unit 32 are both disposed within the reaction frame 1, and are spaced apart along the length of the reaction frame 1 within the first cavity 122. A rotating shaft 10 is located between the first expansion unit 31 and the second expansion unit 32. A specimen 103 and the rotating shaft 10 are positioned opposite each other in the width direction of the reaction frame 1. The third expansion unit 33 and the fourth expansion unit 34 are disposed within the second cavity 123, and are spaced apart from each other across the width of the reaction frame 1. Similarly, the fourth expansion unit 34 and the second expansion unit 32 are spaced apart across the width of the reaction frame 1. The specimen 103 is disposed between the third expansion unit 33 and the fourth expansion unit 34. Specifically, as shown... Figure 14As shown, the first expansion unit 31, the second expansion unit 32, the third expansion unit 33, and the fourth expansion unit 34 are all air cushions. The first expansion unit 31 and the third expansion unit 33 are located at the left end of the loading plate 2, with the first expansion unit 31 located on the upper surface of the loading plate 2 and the third expansion unit 33 located on the lower surface of the loading plate 2. The second expansion unit 32 and the fourth expansion unit 34 are located at the right end of the loading plate 2, with the second expansion unit 32 located on the upper surface of the loading plate 2 and the fourth expansion unit 34 located on the lower surface of the loading plate 2. The specimen 103 is located below the loading plate 2 and in the middle of the loading plate 2. Thus, the arrangement of the first expansion unit 31, the second expansion unit 32, the third expansion unit 33, and the fourth expansion unit 34 can drive the loading plate 2 to rotate, thereby applying a bending moment to the specimen 103. Therefore, when measuring the mechanical properties of the specimen 103, the bending moment applied to the specimen 103 should be consistent with the actual usage state in engineering.

[0080] like Figure 14 As shown, when the rotating shaft 10 is a horizontal axis, the pneumatic loading test machine in this embodiment is a bending moment loading test machine. Furthermore, the pneumatic loading test machine in this embodiment can be laid flat, i.e., the rotating shaft 10 becomes a vertical axis, at which point the pneumatic loading test machine is a structural torque loading test machine. In this case, the expansion assembly 3 is in the second state, and the amount of expansion medium introduced into the two expansion units in the same cavity is different. In other words, the amount of expansion medium introduced into the first expansion unit 31 and the second expansion unit 32 in the first cavity 122 is different, while the amount of expansion medium introduced into the third expansion unit 33 and the fourth expansion unit 34 in the second cavity 123 is different. However, the amount of expansion medium introduced along the axis of the first expansion unit 31 and the fourth expansion unit 34 is the same, and the amount of expansion medium introduced along the axis of the second expansion unit 32 and the third expansion unit 33 is the same. This results in the loading plate 2 being subjected to a bending moment about the rotation axis 10 due to the combined thrust from the first expansion unit 31 and the third expansion unit 33 on the left end, and the combined thrust from the second expansion unit 32 and the fourth expansion unit 34 on the right end. The two combined thrusts are of the same magnitude but opposite in direction.

[0081] It is worth noting that torque is a special type of bending moment. In structural engineering, the torque induced in specimen 103 primarily induces shear stress, and torque typically causes specimen 103 to rotate around its principal axis. Bending moment, on the other hand, induced in specimen 103 primarily induces tensile and compressive stress, causing specimen 103 to bend within a plane passing through its principal axis. Since the specimen 103 primarily tested in this experimental machine is subjected to vertical forces, we can assume that the principal axis of specimen 103 is vertical. Therefore, the torque has its moment axis along a vertical line, while the bending moment's moment axis is a horizontal line.

[0082] The working principle of the pneumatic loading structure testing machine 100 in the first embodiment of the present invention is as follows:

[0083] Vibration tests are conducted using the pneumatic loading structural testing machine 100 of this invention. After the specimen 103 is placed on the ground or at the center of the base plate 13, it still maintains a certain distance from the moving loading plate 2 above. The height of the expansion component 3 is increased by inflating the air cushion through the air inlet. After the upper surface of the expansion component 3 contacts the bottom of the reaction beam 9 and generates pressure, the lower surface of the expansion component 3 applies a downward thrust to the moving loading plate 2, causing the moving loading plate 2 to move vertically downwards until it contacts the specimen 103. The upper and lower surfaces of the specimen 103 are subjected to pressure from the moving loading plate 2 and the base plate 13 or the ground, respectively. By adjusting the amount of gas injected into the cavity of the expansion component 3 and monitoring the output signals of the first inspection component 4 and the second detection component 5, the pressure on the specimen 103 can be accurately adjusted. Because the expansion component 3 has relatively low stiffness and damping, this invention can accurately simulate the boundary conditions of the specimen 103 vibrating in the structure. After the pressure loading of specimen 103 is completed, the vibration component 6 arranged on the base plate 13 or the ground outputs a vibration signal and passes through specimen 103 and the moving loading plate 2 in sequence. Finally, the vibration signal is received by the third detection component 7 and the fourth detection component 8 arranged in the moving loading plate 2. The characteristic frequency of specimen 103 can be determined by analyzing the transfer function of the vibration signal emitted by the vibration component 6 and the vibration signal received by the third detection component 7 and the fourth detection component 8.

[0084] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element 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.

[0085] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0086] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0087] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0088] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0089] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pneumatic loading structure testing machine, characterized in that, include: A reaction frame, comprising a reaction beam and a support portion, wherein the reaction beam is disposed on the support portion; A loading plate is disposed on the support and is spaced apart from the reaction beam along the extension direction of the support to form a first cavity. The side of the loading plate away from the reaction beam forms a second cavity with the reaction frame. The loading plate is rotatable relative to the reaction frame about the width direction of the reaction frame. An expansion assembly is disposed in at least one of a first cavity and a second cavity, the second cavity being adapted to mount a specimen and the specimen abutting against the loading plate, the expansion assembly being adapted to introduce an expansion medium to adjust the force exerted by the loading plate on the specimen, and the stiffness and damping of the expansion assembly being less than the stiffness and damping of the specimen. It also includes a rotating shaft, which passes through the loading plate and is rotatably disposed within the reaction frame. The expansion assembly includes a first expansion unit, a second expansion unit, a third expansion unit, and a fourth expansion unit. The first and second expansion units are both disposed within the reaction frame, and are spaced apart along the length of the reaction frame. The rotating shaft is located between the first and second expansion units. The specimen and the rotating shaft are positioned opposite each other along the width of the reaction frame. The third expansion unit and the fourth expansion unit are disposed in the second cavity. The third expansion unit and the first expansion unit are arranged opposite each other at a width interval in the reaction frame. The fourth expansion unit and the second expansion unit are arranged opposite each other at a width interval in the reaction frame. The specimen is disposed between the third expansion unit and the fourth expansion unit.

2. The pneumatic loading structure testing machine according to claim 1, characterized in that, It also includes a first detection component, which is disposed within the second cavity and located between the specimen and the loading plate. The first detection component is used to detect the force exerted by the loading plate on the specimen. And / or, the pneumatic loading structure testing machine further includes a second detection component, which is located in the second cavity and on the side of the specimen away from the loading plate. The second detection component is used to detect the force exerted by the loading plate on the specimen.

3. The pneumatic loading structure testing machine according to claim 1, characterized in that, The expansion assembly has a first state and a second state. In the first state, the expansion medium introduced into two adjacent expansion units is the same. In the second state, the expansion medium introduced into two adjacent expansion units is different.

4. The pneumatic loading structure testing machine according to claim 1, characterized in that, It also includes a vibration assembly, which is disposed in the second cavity on the side of the specimen away from the loading plate. The vibration assembly can emit vibration signals to drive the specimen to vibrate.

5. The pneumatic loading structural testing machine according to any one of claims 1-4, characterized in that, Also includes: The third detection component is disposed inside the loading plate and is used to detect the vibration signal on one side of the specimen. A fourth detection component is disposed in the second cavity and located on the side of the specimen away from the loading plate. The fourth detection component is used to detect the vibration signal on the other side of the specimen.

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