A test device for realizing compression-bending boundary conditions under axial impact

Abstract

The present invention relates to the technical field of building structure testing, specifically a device for testing compression-bending boundary conditions under axial impact. The device comprises a test platform, a compression-bending assembly, an axial loading assembly, a drop hammer, and a vertically arranged test specimen. The test platform includes a top reaction platform and a bottom reaction platform. The compression-bending assembly comprises a lower loading plate fixed to the upper surface of the bottom reaction platform, a lower hinged plate, an upper hinged plate, an upper loading plate, a lower roller, and an upper roller. The lower hinged plate is hinged to the lower loading plate via the lower roller. An axial loading assembly is disposed between the upper loading plate and the top reaction platform. The upper hinged plate is hinged to the upper loading plate via the upper roller. The test specimen is positioned between the upper hinged plate and the lower hinged plate, with the specimen axis offset from the axis of the upper roller and / or the lower roller, such that the specimen withstands an offset axial load applied by the axial loading assembly. The device has a simple structure and is easy to implement.

Description

Technical Field

[0001] The present invention relates to the technical field of building structure testing, in particular to a device for testing compression-bending boundary conditions under axial impact. Background Art

[0002] In addition to static loads (both dead and live) during construction and their service life, building structures may also experience impact loads from accidents such as dropped construction tools, vehicle collisions, and terrorist attacks. Building structures can be damaged and fail under impact, and in severe cases, may experience progressive structural collapse, causing significant losses. Therefore, impact loads must be considered in the design of some important and specialized structures. Consequently, experimental research on the mechanical properties of building structural components under impact loads has practical engineering significance.

[0003] At present, conventional impact tests are mostly lateral impacts, and the collapse of the structure during the actual impact process often causes axial impact on the components. Finally, the building components transfer the load and energy to the entire structure. Therefore, the axial impact resistance of the building components is very important to the overall stability of the structure. In addition, considering that actual building components are mostly subjected to compression and bending loads before the impact occurs, it is necessary to invent a test device that simulates the axial impact of compression and bending components. Summary of the Invention

[0004] The purpose of the present invention is to provide a test device for realizing compression-bending boundary conditions under axial impact.

[0005] The present invention is implemented by adopting the following technical solutions: a device for testing the boundary conditions of compression and bending under axial impact, comprising a test platform, a compression and bending assembly, an axial loading assembly, a drop hammer and a vertically arranged test piece; the test platform comprises a top reaction platform and a bottom reaction platform arranged in parallel up and down, and the bottom reaction platform and the top reaction platform are fixedly connected by an axially arranged long screw (it is well known to those skilled in the art that generally there are four long screws and they are arranged at the four corners between the top reaction platform and the bottom reaction platform. If the top reaction platform and the bottom reaction platform need to be reinforced, more than four screws can be provided), and an upper drop hammer impact port is provided at the center of the top reaction platform; the compression and bending assembly comprises a fixed The lower loading plate, lower hinge plate, upper hinge plate, upper loading plate, lower roller and upper roller are fixed on the upper surface of the bottom reaction platform. The lower hinge plate is located at the upper part of the lower loading plate and the lower roller is located in the lower groove corresponding to the lower hinge plate and the lower loading plate, so that the lower hinge plate is hinged to the lower loading plate through the lower roller. An axial loading assembly is provided between the upper loading plate and the top reaction platform. The upper hinge plate is located at the lower part of the upper loading plate and the upper roller is located in the upper groove corresponding to the upper hinge plate and the upper loading plate, so that the upper hinge plate is hinged to the upper loading plate through the upper roller. The specimen is located between the upper hinge plate and the lower hinge plate and the axis of the specimen deviates from the axis of the upper roller and / or the lower roller so that the specimen bears the offset axial load loaded by the axial loading assembly.

[0006] When using this test device, first fix the top reaction platform to the ground, use a long screw to fix the bottom reaction platform to the top reaction platform, determine the position of the top reaction platform according to the size of the specimen and each component, and fix it so that enough operating space is reserved between the top reaction platform and the bottom reaction platform. Then install the bending assembly and the axial loading assembly between the top reaction platform and the bottom reaction platform. After the installation is completed, use the axial loading assembly to load the static axial force. After loading is completed, use a drop hammer to impact the specimen, and observe and study the mechanical properties of the specimen under the action of axial impact.

[0007] The beneficial effects of the present invention are as follows: the present invention has a simple structure and is easy to install and disassemble, and can simulate the impact resistance of test components under compression-bending boundary conditions and axial impact conditions, and is used to study the mechanical properties of the overall structure of the load-bearing components of the building structure under axial impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is an overall schematic diagram of the present invention;

[0009] Figure 2 for Figure 1 AA cross-section of

[0010] Figure 3 for Figure 1 A partial enlarged schematic diagram of the upper middle part;

[0011] Figure 4 This is the exploded view of the upper press-bend component;

[0012] Figure 5 This is the exploded view of the press-bend component below;

[0013] Figure 6 Schematic diagram of the structure of the top reaction platform;

[0014] Figure 7 Schematic diagram of the structure of the pad;

[0015] Figure 8 Schematic diagram of the structure of the adjustment pad.

[0016] In the figure: 1—drop hammer, 2—test piece, 3—top reaction platform, 4—bottom reaction platform, 5—long screw, 6—upper drop hammer impact port, 7—lower drop hammer impact port, 8—lower loading plate, 9—lower hinged plate, 10—lower roller, 11—lower end plate, 12—lower tenon, 13—upper loading plate, 14—upper hinged plate, 15—upper roller, 16—upper end plate, 17—upper tenon, 18—jack, 19—disc spring, 20—axial force sensor, 21—adjusting pad, 22—magnetic base, 23—pad, 24—upper lifting ring, 25—lower lifting ring. DETAILED DESCRIPTION

[0017] like Figures 1 to 7As shown, a test device for realizing compression-bending boundary condition under axial impact, comprising a test platform, a compression-bending assembly, an axial loading assembly, a drop hammer 1 and a vertically arranged test piece 2; the test platform comprises a top reaction platform 3 and a bottom reaction platform 4 arranged in parallel above and below, and the bottom reaction platform 4 and the top reaction platform 3 are fixedly connected by an axially arranged long screw 5 (it is well known to those skilled in the art that generally there are four long screws 5 and they are arranged at the four corners between the top reaction platform 3 and the bottom reaction platform 4. If the top reaction platform 3 and the bottom reaction platform 4 need to be reinforced, more than four screws can be provided). An upper drop hammer impact port 6 is provided at the center of the top reaction platform 3; the compression-bending assembly comprises a lower loading plate 8 fixed to the upper surface of the bottom reaction platform 4, a lower hinged plate 9, The upper hinge plate 14, the upper loading plate 13, the lower roller 10, and the upper roller 15, the lower hinge plate 9 is located at the upper part of the lower loading plate 8 and the lower roller 10 is located in the lower groove corresponding to the lower hinge plate 9 and the lower loading plate 8, so that the lower hinge plate 9 is hinged to the lower loading plate 8 through the lower roller 10, and an axial loading assembly is provided between the upper loading plate 13 and the top reaction platform 3, the upper hinge plate 14 is located at the lower part of the upper loading plate 13 and the upper roller 15 is located in the upper groove corresponding to the upper hinge plate 14 and the upper loading plate 13, so that the upper hinge plate 14 is hinged to the upper loading plate 13 through the upper roller 15, the specimen 2 is located between the upper hinge plate 14 and the lower hinge plate 9, and the axis of the specimen 2 deviates from the axis of the upper roller 15 and / or the lower roller 10, so that the specimen 2 bears the offset axial load loaded by the axial loading assembly.

[0018] When using this test device, first fix the top reaction platform 3 to the ground, use the long screw 5 to fix the bottom reaction platform 4 to the top reaction platform 3, determine the position of the top reaction platform 3 according to the size of the specimen 2 and each component, and fix it so that enough operating space is reserved between the top reaction platform 3 and the bottom reaction platform 4, then install the bending assembly and the axial loading assembly between the top reaction platform 3 and the bottom reaction platform 4, and after the installation is completed, use the axial loading assembly to load the static held axial force, and after loading is completed, use the drop hammer 1 to impact the specimen 2, and observe and study the mechanical properties of the specimen 2 under the action of axial impact.

[0019] In practice, the axial loading assembly includes a jack 18 and a disc spring 19. The cylinder of jack 18 is fixedly connected to the top reaction platform 3. The piston rod of jack 18 applies a static axial force to the upper hinged support via the disc spring 19. An axial force sensor 20 is installed between the disc spring 19 and the upper hinged support. After the specimen is axially loaded, the axial force is measured by the axial force sensor. After reaching the specified load, the force remains constant. The specimen is then impacted with a drop hammer, and the impact force is transmitted through the axial force sensor to a computer for further research.

[0020] During specific implementation, an upper end plate 16 is further provided between the specimen 2 and the upper hinged plate 14, the middle part of the lower surface of the upper end plate 16 is fixedly connected to the specimen 2, the upper surface of the upper end plate 16 is provided with an upper tenon 17, and the lower bottom surface of the upper hinged plate 14 is provided with an upper hole adapted to the upper tenon 17, and a lower end plate 11 is further provided between the specimen 2 and the lower hinged plate 9, the middle part of the upper surface of the lower end plate 11 is fixedly connected to the specimen 2, the lower surface of the lower end plate 11 is provided with a lower tenon 12, and the upper surface of the lower hinged plate 9 is provided with a lower hole adapted to the lower tenon 12. This structure can change the offset position of the specimen 2 relative to the upper roller 15 / lower roller 10 by adjusting the position of the upper tenon 17 / lower tenon 12 on the upper end plate 16 / lower end plate 11. The position of the upper tenon 17 / lower tenon 12 can be selected relative to the upper end plate 16 / lower end plate 11 according to the test requirements, and upper end plates 16 / lower end plates 11 of various specifications can be prepared in advance.

[0021] In specific implementation, a pad 23 is provided between the top reaction platform 3 and the cylinder of the jack 18. The pad 23 is fixedly connected to the top reaction platform 3 and a lower drop hammer impact port 7 is provided in the middle of the pad 23 to match the upper drop hammer impact port 6. Upper lifting rings 24 are provided at the left and right ends of the pad 23, and lower lifting rings 25 are provided at the left and right ends of the upper loading plate 13. During installation, the upper lifting ring 24 and the lower lifting ring 25 are connected by a cable to achieve horizontal stability of the upper loading plate 13. This structure makes it convenient to achieve horizontal stability of the upper loading plate 13 when installing this device. After installation, the cable can be removed. Figure 8 As shown, during installation, an adjustment block 21 is placed between the lower hinge plate 9 and the lower loading plate 8 to help maintain the lower hinge plate 9 in a horizontal and stable position. This facilitates installation. After installation, the adjustment block 21 is removed. The adjustment block 21 comprises a magnetic base 22 that is attracted to the lower loading plate 8 and a bolt. The bolt heads contact the left and right sides of the lower surface of the lower hinge plate 9, and the bolt shanks are bolted to the magnetic base 22. This simple structure facilitates installation and removal, and the bolts can be adjusted to the desired height.

[0022] In this embodiment, the top reaction platform 3 is fixedly connected to the backing plate 23 by screws and tightening nuts. The lower loading plate 8 is fixedly connected to the bottom reaction platform 4 by bolts. The jack 18 is a hydraulic jack.

Claims

1. A device for testing bending boundary conditions under axial impact, characterized in that: The invention comprises a test platform, a compression bending assembly, an axial loading assembly, a drop hammer (1) and a vertically arranged test piece (2); the test platform comprises a top reaction platform (3) and a bottom reaction platform (4) arranged in parallel, the bottom reaction platform (4) and the top reaction platform (3) are fixedly connected by an axially arranged long screw (5), and an upper drop hammer impact port (6) is provided at the center of the top reaction platform (3); the compression bending assembly comprises a lower loading plate (8), a lower hinged plate (9), an upper hinged plate (14), an upper loading plate (13), a lower roller (10), and an upper roller (15) fixed to the upper surface of the bottom reaction platform (4), the lower hinged plate (9) being located on the upper part of the lower loading plate (8) and the lower roller (10) being located on the lower hinged plate (9). ) is hinged to the lower loading plate (8) through the lower roller (10) in the lower groove corresponding to the lower loading plate (8), an axial loading assembly is provided between the upper loading plate (13) and the top reaction platform (3), the upper hinge plate (14) is located at the lower part of the upper loading plate (13) and the upper roller (15) is located in the upper groove corresponding to the upper hinge plate (14) and the upper loading plate (13) to realize the upper hinge plate (14) and the upper loading plate (13) being hinged to the upper loading plate (13) through the upper roller (15), the specimen (2) is located between the upper hinge plate (14) and the lower hinge plate (9) and the axis of the specimen (2) deviates from the axis of the upper roller (15) and / or the lower roller (10) so that the specimen (2) bears the offset axial load loaded by the axial loading assembly.

2. The device for testing bending boundary conditions under axial impact according to claim 1, characterized in that: The axial loading assembly includes a jack (18) and a disc spring (19). The cylinder of the jack (18) is fixedly connected to the top reaction platform (3). The piston rod of the jack (18) provides a static axial force to the upward hinged support through the disc spring (19).

3. The device for testing bending boundary conditions under axial impact according to claim 2, characterized in that: An axial force sensor (20) is installed between the disc spring (19) and the upper hinge support.

4. A device for testing bending boundary conditions under axial impact according to claim 1, 2 or 3, characterized in that: An upper end plate (16) is further provided between the specimen (2) and the upper hinge plate (14), the middle portion of the lower surface of the upper end plate (16) is fixedly connected to the specimen (2), an upper tenon (17) is provided on the upper surface of the upper end plate (16), and an upper hole matching the upper tenon (17) is provided on the lower bottom surface of the upper hinge plate (14). A lower end plate (11) is further provided between the specimen (2) and the lower hinge plate (9), the middle portion of the upper surface of the lower end plate (11) is fixedly connected to the specimen (2), a lower tenon (12) is provided on the lower surface of the lower end plate (11), and a lower hole matching the lower tenon (12) is provided on the upper surface of the lower hinge plate (9).

5. The device for testing bending boundary conditions under axial impact according to claim 4, characterized in that: During installation, an adjustment pad (21) is placed between the lower hinge plate (9) and the lower loading plate (8) to keep the lower hinge plate (9) horizontal and stable.

6. The device for testing bending boundary conditions under axial impact according to claim 5, characterized in that: The adjusting pad (21) comprises a magnetic base (22) adsorbed on the lower loading plate (8) and a bolt, wherein the bolt head is placed on the left and right sides of the lower surface of the lower hinge plate (9), and the bolt rod is bolted to the magnetic base (22).

7. The device for testing bending boundary conditions under axial impact according to claim 6, characterized in that: A pad (23) is provided between the top reaction platform (3) and the cylinder body of the jack (18), the pad (23) is fixedly connected to the top reaction platform (3), and a lower drop hammer impact opening (7) adapted to the upper drop hammer impact opening (6) is provided in the middle of the pad (23), upper lifting rings (24) are provided at the left and right ends of the pad (23), and lower lifting rings (25) are provided at the left and right ends of the upper loading plate (13). During installation, the upper lifting ring (24) and the lower lifting ring (25) are connected by a cable to achieve horizontal stability of the upper loading plate (13).

8. The device for testing bending boundary conditions under axial impact according to claim 7, characterized in that: The top reaction platform (3) and the pad (23) are fixedly connected via a screw and a tightening nut.

9. The device for testing bending boundary conditions under axial impact according to claim 8, characterized in that: The lower loading plate (8) and the bottom reaction platform (4) are fixedly connected via bolts.

10. The device for testing bending boundary conditions under axial impact according to claim 9, characterized in that: The jack (18) is a hydraulic jack (18).

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