Dynamic crack opening and closing pull-out testing machine

Abstract

The utility model belongs to the field of testing machines, relates to a mechanical anchor bolt test for concrete, and particularly provides a dynamic crack opening and closing pull-out testing machine which comprises a main machine frame, a fixed clamping block, a movable clamping block, a crack reciprocating opening and closing actuator, a pull-out device and a shearing device, the shearing device comprises a shearing mounting plate, a shearing actuator, a shearing guide assembly, a clamping plate, a connecting rod and a nut connected with the connecting rod, a reinforcing sleeve is arranged between the portion, close to the shearing mounting plate, of the clamping plate and the shearing mounting plate, the connecting rod is sleeved with the reinforcing sleeve, and a plurality of fixing cylinders are arranged on the shearing mounting plate in pairs; a stretching stroke limiting switch is arranged on the drawing device, and opening and closing stroke limiting switches are arranged on the top and the side face of the test piece. The device is reasonable in design, simple in structure, relatively high in detection capability, relatively high in practicability, beneficial to improving the detection accuracy and suitable for large-scale popularization.

Description

Technical Field

[0001] This utility model belongs to the field of testing machines, and relates to the testing of mechanical anchor bolts for concrete, and in particular to a dynamic crack opening and closing pull-out testing machine. Background Technology

[0002] Concrete is one of the most important engineering materials in civil engineering, and it is generally reinforced with steel bars, mechanical anchors, or added fibers. For concrete components with mechanical anchors, dynamic crack testing is required. Dynamic and static loading test systems for concrete testing can detect the physical properties of the corresponding engineering materials by pulling and probing the mechanical anchors in multiple directions.

[0003] Existing patent CN117405495A discloses a concrete crack opening and closing pull-out fatigue performance testing device. This application fixes the concrete block to be tested to the top of a machine platform, and vertically connects an anchor bolt body to the top of the platform. An oscillation application component located on the outside of the platform drives a force-applying component to reciprocate, applying an oscillation effect to the anchor bolt body. The seismic resistance of the connection can be determined by observing the cracks generated at the connection between the anchor bolt body and the concrete block due to the oscillation effect. This testing device can test anchor bolts in different orientations from multiple directions; for example, the hydraulic push rod of the device can rotate from horizontal to vertical or from vertical to horizontal. However, the stability during the actual testing process may have some unreliable factors, thus increasing the test error and affecting the accuracy of the test.

[0004] Existing patent CN117740533A discloses a device for testing the dynamic and static loads of concrete mechanical anchors, including a support platform, a guide rail mounted on the support platform, a slider slidably connected to the guide rail, two clamping blocks (one mounted on the slider and the other on the support platform) for clamping cracked concrete, an actuator mounting bracket between the clamping blocks, a pull-out device placed on the cracked concrete for performing pull-out tests on the anchors, a shearing plate mounted on one side of the support platform with a shearing device, and a shearing sleeve mounted on the piston rod of the shearing device, and a support plate placed on the upper surface of the support platform. While the shearing device of this device has a pull-out function, the support reaction force during the pull-out process relies heavily on the adjusting block and the sliding rod. The anti-overturning effect of the mounting surface where the shearing device is located needs improvement; otherwise, it will directly affect the pull-out test results in that direction. Secondly, since this device is an automatic pull-out testing machine, the lack of a corresponding positioning mechanism will affect the connection effect between the anchor and the actuator in the pull-out direction, especially the pull-out device in the vertical direction, which will increase the error in the test results. Utility Model Content

[0005] This invention addresses the technical problems existing in the aforementioned testing machines by proposing a dynamic crack opening and closing pull-out testing machine that is rationally designed, has strong testing capabilities, is highly practical, and helps improve testing accuracy.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a dynamic crack opening and closing pull-out testing machine, including a main frame. The main frame is provided with relatively distributed fixed clamping blocks and movable clamping blocks. A specimen is placed between the movable clamping blocks and the fixed clamping blocks. A pair of crack reciprocating opening and closing actuators are provided at both ends of the movable and fixed clamping blocks. A pull-out device is provided above the specimen. A shearing device is provided on the specimen at a position horizontally and vertically to the crack reciprocating opening and closing actuators. The shearing device includes a shearing mounting plate, and a shearing actuator is provided on the shearing mounting plate. The shearing mounting plate is connected to a shearing guide assembly. Clamping plates are provided on both sides of the specimen. Multiple connecting rods are arranged in pairs on the clamping plates. Nuts connected to the connecting rods are provided on the side of the clamping plate furthest from the shearing mounting plate. A reinforcing sleeve is provided between the clamping plate and the shearing mounting plate, and the reinforcing sleeve is fitted over the connecting rods. Multiple fixing cylinders are arranged in pairs on the shearing mounting plate. The fixing cylinders are fitted over the connecting rods and have positioning pins that mate with the connecting rods. A tension stroke limit switch is provided on the pulling device. Opening and closing stroke limit switches are provided on the top and sides of the specimen.

[0007] Preferably, both the clamping plate and the shearing mounting plate are provided with four oblong holes, in which a pull rod is provided. One end of the pull rod is provided on the shearing actuator. The shearing actuator has a groove-shaped structure with a sleeve hole in the middle. The sleeve hole cooperates with the anchor bolt provided on the top of the specimen. The pull rod has a mounting seat at the end facing away from the shearing mounting plate. The mounting seat is connected to the shearing actuator.

[0008] Preferably, the shear guide assembly includes an anti-tilt slide, which is slidably mounted on a side guide rail. The side guide rail is inclinedly mounted on the side of the main frame, and the sliding plane of the anti-tilt slide and the supporting surface of the side guide rail are both inclined.

[0009] Preferably, the pulling device includes a tapered frame, a pulling actuator is provided at the center of the tapered frame, the telescopic end of the pulling actuator faces downward and is provided with a universal hinge support, the center of the universal hinge support is provided with a central hole for the anchor bolt to pass through, and the tension stroke limit switch is provided on the side of the universal hinge support.

[0010] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0011] 1. This utility model provides a dynamic crack opening and closing pull-out testing machine. A clamping plate serves as the contact base between the shearing device and the specimen. Multiple connecting rods, reinforcing sleeves, and fixing sleeves improve the support stability between the specimen and the shearing actuator, enhancing the overall anti-overturning performance of the shearing device and thus improving the testing accuracy of this station. Tensile stroke limit switches and opening / closing stroke limit switches serve as limiting structures for the tensile action and the crack reciprocating opening and closing action, improving the control effect of the pull-out actuator on the tensile amplitude and the crack reciprocating opening / closing actuator on the crack opening and closing amplitude. This device is rationally designed, simple in structure, has strong testing capabilities, high practicality, and improves testing accuracy, making it suitable for large-scale promotion. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 An isometric view of a dynamic crack opening and closing pull-out testing machine provided for an embodiment;

[0014] Figure 2 A top view of a dynamic crack opening and closing pull-out testing machine provided in the embodiment;

[0015] Figure 3 A side view of a dynamic crack opening and closing pull-out testing machine provided for an embodiment;

[0016] Figure 4 An isometric view of the drawing device provided in the embodiment;

[0017] Figure 5 Axonometric view of the shearing device provided in the embodiment;

[0018] In the above figures, 1. Main frame; 2. Fixed clamping block; 3. Movable clamping block; 4. Specimen; 5. Crack reciprocating actuator; 6. Pulling device; 61. Tension stroke limit switch; 62. Conical frame; 63. Pulling actuator; 64. Universal hinge support; 7. Shearing device; 71. Shearing mounting plate; 72. Shearing actuator; 73. Shearing guide assembly; 731. Anti-tilting slide seat; 732. Side guide rail; 74. Clamping plate; 75. Connecting rod; 76. Nut; 77. Reinforcing sleeve; 78. Fixed cylinder; 79. Positioning pin; 710. Waist-shaped hole; 711. Tie rod; 712. Shearing actuator; 713. Sleeve hole; 714. Mounting seat; 8. Opening and closing stroke limit switch; 9. Anchor bolt. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" appearing below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0021] Examples, such as Figure 1 As shown in Figure 5, the dynamic crack opening and closing pull-out testing machine provided by this utility model includes a main frame 1. The main frame 1 is provided with relatively distributed fixed clamping blocks 2 and movable clamping blocks 3. A specimen 4 is placed between the movable clamping blocks 3 and the fixed clamping blocks 2. A pair of crack reciprocating opening and closing actuators 5 are provided at both ends of the movable clamping blocks 3 and the fixed clamping blocks 2. A pull-out device 6 is provided above the specimen 4. A shearing device 7 is provided on the specimen 4 at a position horizontal and vertical to the crack reciprocating opening and closing actuators 5. The shearing device 7 includes a shearing mounting plate 71, on which a shearing actuator 72 is provided. The shearing mounting plate 71 is guided by a shearing guide assembly 73. Clamping plates 74 are provided on both sides, and multiple connecting rods 75 are provided in pairs on the clamping plates 74. Nuts 76 connected to the connecting rods 75 are provided on the side of the clamping plate 74 located away from the shearing mounting plate 71. A reinforcing sleeve 77 is provided between the clamping plate 74 and the shearing mounting plate 71 located near the shearing mounting plate 71. The reinforcing sleeve 77 is sleeved on the outside of the connecting rods 75. Multiple fixing cylinders 78 are provided in pairs on the shearing mounting plate 71. The fixing cylinders 78 are sleeved on the connecting rods 75 and the fixing cylinders 78 are provided with positioning pins 79 that cooperate with the connecting rods 75. A tension stroke limit switch 61 is provided on the pulling device 6. Opening and closing stroke limit switches 8 are provided on the top and sides of the specimen 4. The crack reciprocating actuator 5, shearing actuator 72, and pulling actuator 63 are equipped with imported pump stations. These pump stations utilize low-noise linear conjugate internal gear pumps and a hydraulic module consisting of an overflow valve, accumulator, directional valve, and precision oil filter. This ensures the system starts under low pressure and achieves soft switching between high and low pressure. The systems feature alarms or shutdown functions for oil temperature (below 10℃, above 55℃), liquid level, and oil filter blockage. The load sensors used in the crack reciprocating actuator 5, pulling actuator 63, and shearing actuator 72 have a 150% overload capacity and, in conjunction with the control system, an accuracy of 0.1%FS.

[0022] The crack reciprocating actuator 5 is used for pull-out tests and amplitude-pulsating tensile load tests on anchor bolts. Its maximum loading force is 1000kN×2; operating frequency: 0.01~5HZ; dynamic amplitude-frequency characteristics: 0.1HZ-31.3mm, 0.5HZ-6.3mm; maximum displacement stroke: 1000mm. The crack reciprocating actuator 5 is mounted on the main frame 1, and its piston rod is connected to the movable rebar fixing clamp via a hinge device and a load sensor. During the test, the exposed concrete rebar is securely installed in the left and right rebar fixing clamps. After the crack reciprocating servo controller provides a control signal, the crack reciprocating actuator 5 drives the movable rebar fixing clamp to move servo-driven, forming a feedback closed loop with the crack measuring instrument to control the crack size.

[0023] Regarding the pull-out actuator 63 of the pull-out device 6, its maximum loading force is 250kN, operating frequency is 0.01~15HZ, dynamic amplitude-frequency characteristics: 0.1HZ-37.5mm; 0.5HZ-7.5mm; pull-out measurement: stroke ±150mm. The anchor bolt pull-out test is completed by the pull-out device 6 assembly. The assembly is moved to a suitable position using workshop hoisting / overhead crane equipment. The anchor bolt is connected to the piston rod of the pull-out actuator 63 via a hinge. The support surface of the tapered frame 62 is adjusted, the pull-out servo controller sends a pull-out signal, and then the anchor bolt is subjected to a pull-out test. The pull-out force is detected by a pull-out load sensor, and the pull-out displacement is detected by a built-in magnetic telescopic displacement sensor. The pull-out actuator can be equipped with an automatic self-aligning device to ensure coaxiality of the load; unidirectional force is used to avoid the anchor bolt being subjected to compressive loads if it rotates in the opposite direction during loading.

[0024] Regarding the shearing device 7, it is used to perform shear tests and amplitude-pulsating shear loads on the anchor bolts. The shearing actuator 72 has a built-in magnetic expansion displacement sensor, a maximum loading force of 250kN, an operating frequency of 0.01~15HZ, and dynamic amplitude-frequency characteristics of 0.1HZ-37.5mm and 0.5HZ-7.5mm. Shear measurement: stroke ±150mm. The anchor bolt shear test is completed by the shearing device 7 assembly. The assembly is moved to a suitable position, and the anchor bolt is connected to the piston rod of the shearing actuator 72 via a hinge. The shearing servo controller sends a pull-out signal, and then the shear test is performed on the anchor bolt. The shearing force is detected by the shear load sensor, and the shearing displacement is detected by its built-in magnetic expansion displacement sensor. The reciprocating opening and closing of the crack, the anchor bolt shearing, and the anchor bolt pull-out are controlled by their respective independent control systems.

[0025] Specifically, this device uses a clamping plate 74 as the contact base between the shearing device 7 and the specimen 4. Multiple connecting rods 75, reinforcing sleeves 77, and fixing sleeves 78 improve the stability and balance of the shearing station formed by the specimen 4, clamping plate 74, and shearing mounting plate 71. During the shearing detection action performed by the shearing actuator 72, the overall stability of the shearing device 7 is ensured, which is beneficial to improving the overall anti-overturning performance of the shearing device 7, and thus improving the detection accuracy of this detection station. Simultaneously, this equipment uses a tensile stroke limit switch 61 and an opening / closing stroke limit switch 8 as the limiting structures for the tensile action and the crack reciprocating opening / closing action, which is beneficial to improving the control effect of the pull-out actuator 63 on the tensile amplitude and the crack reciprocating opening / closing actuator 5 on the crack opening / closing amplitude, thus improving detection accuracy. Furthermore, the two crack opening and closing reciprocating actuators facilitate synchronous control of deformation loads. Each of the shearing actuator, pulling actuator, and crack opening and closing reciprocating actuator of this equipment is equipped with a corresponding control channel, which can realize multi-channel dynamic control. Each channel can realize closed-loop dynamic control of load-displacement-deformation.

[0026] Furthermore, both the clamping plate 74 and the shearing mounting plate 71 provided by this utility model are provided with four oblong holes 710. A pull rod 711 is provided in each oblong hole 710. One end of the pull rod 711 is provided on the shearing actuator 712. The shearing actuator 712 has a groove-shaped structure and a sleeve hole 713 is provided in the middle. The sleeve hole 713 cooperates with the anchor bolt provided on the top of the specimen 4. A mounting seat 714 is provided at the end of the pull rod 711 facing away from the shearing mounting plate 71. The mounting seat 714 is connected to the shearing actuator 72. The mounting seat 714 is kept synchronized with the pull rod 711 by screws. The pull rod 711 is kept synchronized with the shearing actuator 712. The shearing actuator 72 generates displacement through extension and retraction, causing the shearing actuator 712 to generate shearing force with the anchor bolt. The load sensor and the built-in magnetostrictive displacement sensor of the shearing actuator 72 complete the corresponding detection items.

[0027] To improve the detection accuracy of the shearing device 7, the shearing guide assembly 73 provided by this utility model includes an anti-tilting slide 731, which is slidably mounted on a side guide rail 732. The side guide rail 732 is inclined on the side of the main frame 1, and both the sliding plane of the anti-tilting slide 731 and the supporting surface of the side guide rail 732 are inclined. The basic function of the shearing guide assembly 73 is to provide the shearing device 7 with a movement adjustment margin to achieve a better shearing detection position for the specimen 4. The anti-tilting slide 731 and the side guide rail 732 provide adjustment margin through horizontal movement. At the same time, when the anti-tilting slide 731 and the side guide rail 732 are subjected to a horizontal force from the shearing actuator 72 during the shearing detection process, the pressure can be transmitted to the main frame 1 through the side guide rail 732. Compared with a horizontal supporting surface, it has a better effect on the transmission of force in this direction, which can further improve the detection performance of the shearing device 7 during the shearing detection process.

[0028] To improve the detection effect of the pull-out device 6, the pull-out device 6 provided by this utility model includes a conical frame 62, which provides a supporting plane for the pull-out device 6. A pull-out actuator 63 is arranged at the center of the conical frame 62. The telescopic end of the pull-out actuator 63 faces downward and is provided with a universal hinge support 64. The center of the universal hinge support 64 is provided with a central hole for the anchor bolt to pass through. A tension stroke limit switch 61 is arranged on the side of the universal hinge support 64. The anchor bolt on the specimen 4 can be hinged to the universal hinge support 64 by a pin connection. The universal hinge support 64 can reduce the influence of torque on the pull-out test results and, to a certain extent, play a buffering role, which is beneficial to protecting the pull-out actuator 63.

[0029] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A dynamic crack opening and closing pull-out testing machine, comprising a main frame, on which fixed clamping blocks and movable clamping blocks are arranged in opposite directions, the space between the movable clamping blocks and the fixed clamping blocks is used to place a specimen, a pair of crack reciprocating opening and closing actuators are arranged at both ends of the movable clamping blocks and the fixed clamping blocks, a pull-out device is arranged above the specimen, and a shearing device is arranged on the specimen at a position horizontal and vertical to the crack reciprocating opening and closing actuators, the shearing device comprising a shearing mounting plate, a shearing actuator arranged on the shearing mounting plate, the shearing mounting plate being guided by a shearing guide assembly, characterized in that... The specimen is provided with clamps on both sides, and multiple connecting rods are provided in pairs on the clamps. Nuts connected to the connecting rods are provided on the side of the clamps located away from the shear mounting plate. A reinforcing sleeve is provided between the clamps located near the shear mounting plate and the shear mounting plate. The reinforcing sleeve is sleeved on the outside of the connecting rods. Multiple fixing cylinders are provided in pairs on the shear mounting plate. The fixing cylinders are sleeved on the connecting rods and are provided with positioning pins that cooperate with the connecting rods. The pulling device is provided with a tension stroke limit switch. Opening and closing stroke limit switches are provided on the top and sides of the specimen.

2. The dynamic crack opening and closing pull-out testing machine according to claim 1, characterized in that, Both the clamping plate and the shearing mounting plate are provided with four oblong holes. A pull rod is installed in each oblong hole. One end of the pull rod is installed on the shearing actuator. The shearing actuator has a groove-shaped structure with a sleeve hole in the middle. The sleeve hole cooperates with the anchor bolt installed on the top of the specimen. A mounting seat is provided at the end of the pull rod facing away from the shearing mounting plate. The mounting seat is connected to the shearing actuator.

3. The dynamic crack opening and closing pull-out testing machine according to claim 2, characterized in that, The shear guide assembly includes an anti-tilt slide, which is slidably mounted on a side guide rail. The side guide rail is inclinedly mounted on the side of the main frame, and the sliding plane of the anti-tilt slide and the supporting surface of the side guide rail are both inclined.

4. A dynamic crack opening and closing pull-out testing machine according to claim 1 or 3, characterized in that, The pulling device includes a tapered frame, a pulling actuator is provided at the center of the tapered frame, the telescopic end of the pulling actuator faces downward and is provided with a universal hinge support, the center of the universal hinge support is provided with a central hole for the anchor bolt to pass through, and the tension stroke limit switch is provided on the side of the universal hinge support.

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