A freely adjustable loading frame for low-cycle repeated load tests

Abstract

A freely adjustable low-cycle repeated load test loading frame, a pair of portal frames and a pair of vertical track columns are vertically installed on a base, a first hoist is fixed on the upper crossbeam on the top of the portal frame, the lower end of the first hoist is respectively connected to the two ends of the horizontal track beam, and controls the longitudinal actuator installed on the horizontal track beam to move up and down, the horizontal track beam is fixed or disconnected from the portal frame through a pin, a second hoist is installed on the fixed crossbeam at the upper end of a pair of vertical track columns, the lower end of the second hoist is connected to the movable crossbeam installed with the transverse actuator, the movable crossbeam is fixed or disconnected from the vertical track column through a pin, and the transverse support frame is simultaneously fixed to the vertical track column and the portal frame on the same side through a steel section. The present invention is easy to operate, solves the problem of the actuator moving up and down and left and right and the difficulty of replacement, realizes the electric free adjustment of the actuator, reduces the use of large hoisting equipment, and greatly improves the test efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of building structure energy dissipation and shock absorption test equipment, and relates to a low-cycle repeated load test loading frame, and in particular to a freely adjustable low-cycle repeated load test loading frame. Background Art

[0002] The seismic performance of structures has always been a hot topic of concern. The most mainstream and widely used structural seismic performance test is mainly the low-cycle repeated load test. The low-cycle repeated load test refers to a static test that applies multiple reciprocating cycles to the structure or structural member. It is a process of repeatedly loading and unloading the structure or structural member in both positive and negative directions to simulate the stress and deformation characteristics of the structure in reciprocating vibration during an earthquake. It uses a certain load control or displacement control to load the specimen with low-cycle repeated cycles, so that the specimen is subjected to stress from the beginning to destruction. This is a test method to obtain the inelastic load-deformation characteristics of the structure or structural member, so it is also called a restoring force characteristic test.

[0003] The main purpose of conducting a quasi-static test of a structure is to first establish the restoring force characteristics of the structure under earthquake action, determine the calculation model of the restoring force of the structural components, obtain the equivalent damping ratio of the structure through the hysteresis curve obtained from the test and the area enclosed by the curve, measure the energy dissipation capacity of the structure, and also obtain the skeleton curve, the initial stiffness of the structure, and stiffness degradation parameters. This can further judge and identify the seismic performance of the structure from three aspects: strength, deformation, and energy. Finally, the failure mechanism of the structural components can be studied through experiments to provide a basis for improving the current structural seismic design method and improving the structural design measures.

[0004] In order to adapt to specimens of different specifications, the test loading frame of the low-cycle repeated load test loading device is often very large, and the longitudinal actuator and the transverse actuator are respectively fixed to the corresponding reaction force device to apply axial force and lateral load. However, due to the different size specifications of the specimens, it is often necessary to move the longitudinal actuator and the transverse actuator to meet the needs of test loading. In traditional test loading devices, large-scale lifting equipment is often required to cooperate with multiple workers to spend several days to realize the movement of the reaction force device and the longitudinal actuator and the transverse actuator. Each test will greatly consume manpower and material resources, and the fixation of the longitudinal actuator and the reaction force device itself has a large friction force, which causes a large error effect on the test results. In this regard, the present invention proposes a freely adjustable low-cycle repeated load test loading frame, which realizes the adaptive movement of the longitudinal actuator and the transverse actuator through a hoist, and sets a structure for reducing friction for the longitudinal actuator to improve the accuracy of the test. Summary of the invention

[0005] The present invention aims at the problem that it is difficult to adjust the position of the actuator in the traditional low-cycle repeated load test frame, and provides a freely adjustable low-cycle repeated load test loading frame. The first hoist and the second hoist respectively control the up and down movement of the horizontal track beam and the movable crossbeam, so that the longitudinal actuator and the transverse actuator can be adaptively moved up and down. At the same time, the longitudinal actuator can be adaptively moved horizontally left and right on the horizontal track beam, thereby realizing the free adjustment of the low-cycle repeated load test loading frame, adapting to the loading of specimens of different specifications, without the need to use large machinery for disassembly and installation, saving a lot of manpower and material resources, and effectively improving work efficiency. Bolt holes are provided on the vertical columns and vertical track columns of the portal frame. The horizontal track beam and the movable crossbeam that have been moved into place are fixed and clamped to the portal frame and the vertical track column respectively by inserting a pin. When the horizontal track beam and the movable crossbeam are adaptively moved, the pin is pulled out, and rollers are provided on the contact surfaces of the horizontal track beam and the movable crossbeam with the movable track to facilitate movement.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a freely adjustable low-cycle repeated load test loading frame, comprising a portal frame, a horizontal track beam, a vertical track column, a fixed crossbeam, a movable crossbeam, a first hoist, a second hoist and a base, characterized in that a pair of portal frames and a pair of vertical track columns are vertically installed and fixed on the base, a horizontally arranged upper crossbeam is arranged on the top of the portal frame to horizontally connect the vertical columns on both sides, a first hoist is fixedly installed on the upper crossbeam, the lower end of the first hoist is respectively connected to the two ends of the horizontal track beam, and the horizontal track beam is connected to the portal frame by inserting or pulling out a pin. The frame is pinned and fixed or released, one or more longitudinal actuators are suspended in the middle of the horizontal track beam, the vertical track column is arranged on the outside of the portal frame on one side, the upper ends of a pair of vertical track columns are horizontally connected through a fixed crossbeam, a second hoist is fixedly installed on the fixed crossbeam, the lower end of the second hoist is connected to the movable crossbeam, the transverse actuator is connected to the side of the movable crossbeam by bolts, the movable crossbeam is pinned and fixed or released with the vertical track column by inserting or pulling out the pins, the transverse support frame is laterally consolidated with the vertical track column and the portal frame on the same side by steel sections, to realize a freely adjustable low-cycle repeated load test loading frame.

[0007] The two ends of the horizontal track beam are respectively embedded in the interior of the portal frames at both ends, and the inner groove walls of the vertical columns of the portal frames are used as slide rails. The horizontal track beam is lifted or lowered by the first hoist with the upper cross beam as support to move up and down adaptively, and rollers are provided on the contact surface between the horizontal track beam and the inner groove wall of the vertical column. The rollers reduce the friction of the contact surface and facilitate the movement of the horizontal track beam.

[0008] The tail end of the longitudinal actuator is suspended and installed on the bottom surface of the horizontal track beam, and can be adaptively moved horizontally left and right along the axial direction of the horizontal track beam. A pulley or roller is arranged between the upper connecting plate and the lower connecting plate at the tail end of the longitudinal actuator and the horizontal track beam. The pulley or roller is fixed on the inner side of the upper connecting plate and the lower connecting plate. When the longitudinal actuator moves horizontally left and right, the pulley or roller rolls accordingly, making the adjustment of the longitudinal actuator and the horizontal movement during test loading very easy.

[0009] The vertical columns of the portal frame are provided with a plurality of bolt holes spaced apart along the height direction, and the vertical track columns are provided with a plurality of bolt holes spaced apart along the height direction. At the same time, bolt holes are also provided at the corresponding positions at both ends of the horizontal track beam and on the movable crossbeam. The bolt holes correspond to corresponding pins, and the horizontal track beam and the movable crossbeam are fixed or released by inserting or pulling out the pins into the bolt holes.

[0010] The movable crossbeam is located at the lower part of the fixed crossbeam, embedded between two vertical track columns, with the inner groove wall of the vertical track column as a slide rail, and the movable crossbeam is lifted or lowered by the second hoist with the fixed crossbeam as support to move up and down adaptively, and rollers are arranged on the contact surface between the movable crossbeam and the inner groove wall of the vertical track column to assist in movement.

[0011] The transverse actuator is located at the lower part of the horizontal track beam, and its tail end is fixed to a side surface of the movable crossbeam. The movable crossbeam provides force support for the transverse actuator during movement and loading.

[0012] The center lines of the portal frame, a pair of vertical track columns and the transverse support frame are located in the same straight line along the axis direction of the horizontal track beam.

[0013] After the first hoist and the second hoist respectively lift or lower the horizontal track beam and the movable crossbeam, the horizontal track beam and the movable crossbeam are respectively connected and fixed with the portal frame and the vertical track column pins.

[0014] The base is a steel plate, reinforced concrete plate or ground foundation that connects the portal frame, vertical track columns and transverse support frame as a whole. The portal frame, vertical track columns and horizontal track beams, movable cross beams and the base form an integrated self-balancing system.

[0015] When a freely adjustable low-cycle repeated load test loading frame is implemented, the portal frame, horizontal track beam, transverse support frame, vertical track column, fixed beam and movable beam are all prefabricated assembled components. No large fixed reaction wall is required during laboratory installation, and the installation is flexible and mobile. The loading frame is also equipped with a hoist to lift or drop the longitudinal and transverse actuators up and down. After it is in place, it is fixed by inserting pins in the bolt holes, which avoids the movement of the horizontal track beam and the movable beam during loading, plays a good role in eliminating gaps, and saves large lifting equipment while improving the mobility of the entire test loading frame.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) The horizontal track beam and the movable cross beam are lifted or lowered by the first hoist and the second hoist respectively, and the vertical movement of the longitudinal actuator and the horizontal actuator is realized by combining with the auxiliary roller. At the same time, the longitudinal actuator can be adaptively moved left and right on the horizontal track beam as needed, realizing a freely adjustable low-cycle repeated load test loading frame.

[0018] (2) The actuator can be freely adjusted without the need for large lifting equipment for disassembly and installation, thus reducing the danger of aerial operations. It has a wide range of applications and can match tests of different specifications by moving the vertical and horizontal actuators up and down, left and right, thereby improving the maneuverability and convenience of a freely adjustable low-cycle repeated load test loading frame.

[0019] (3) Bolt holes are provided on the vertical columns and vertical track columns of the portal frame. The horizontal track beams and movable cross beams that have been moved into place are fixed and clamped to the portal frame and vertical track columns respectively by pins, making installation and disassembly convenient and quick.

[0020] (4) The lateral support frame is welded and fixed to the vertical track column and the portal frame at the same time. It not only serves as a reaction device for the lateral actuator, but also improves the stability of the entire test loading frame.

[0021] (5) A pulley or roller is arranged between the upper connecting plate and the lower connecting plate at the tail end of the longitudinal actuator and the horizontal track beam to realize the left and right adaptive movement of the longitudinal actuator during the loading process of the transverse actuator, thereby reducing the influence of the tilt of the longitudinal actuator and the friction force when the tail end of the longitudinal actuator moves, thereby ensuring the accuracy requirements of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional schematic diagram of a freely adjustable loading frame for low-cycle repeated load tests;

[0023] Figure 2 It is a schematic elevation diagram of a freely adjustable low-cycle repeated load test loading frame;

[0024] Figure 3 It is a schematic diagram of a longitudinal actuator loading frame of a freely adjustable low-cycle repeated load test loading frame;

[0025] Figure 4 It is a schematic diagram of a lateral actuator loading frame of a freely adjustable low-cycle repeated load test loading frame;

[0026] Figure 5 It is a schematic diagram of a lateral support frame of a freely adjustable low-cycle repeated load test loading frame;

[0027] Figure 6 It is a schematic diagram of a horizontal rail beam of a freely adjustable loading frame for low-cycle repeated load tests;

[0028] Figure 7 It is a schematic diagram of a movable crossbeam of a freely adjustable loading frame for low-cycle repeated load tests;

[0029] In all the drawings, 1 is a portal frame; 11 is a vertical column; 110 is an upper beam; 2 is a horizontal track beam; 21 is a longitudinal actuator; 211 is an upper connecting plate; 212 is a lower connecting plate; 3 is a vertical track column; 4 is a fixed beam; 5 is a movable beam; 51 is a lateral actuator; 52 is a roller; 6 is a first hoist; 7 is a second hoist; 8 is a bolt hole; 9 is a pin; 10 is a lateral support frame; and 100 is a base. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. A freely adjustable low-cycle repeated load test loading frame comprises a portal frame 1, a horizontal track beam 2, a vertical track column 3, a fixed crossbeam 4, a movable crossbeam 5, a first hoist 6, a second hoist 7 and a base 100, characterized in that a pair of portal frames 1 and a pair of vertical track columns 3 are vertically mounted and fixed on the base 100, a horizontally arranged upper crossbeam 110 is arranged on the top of the portal frame 1 to laterally connect the vertical columns 11 on both sides, the upper crossbeam 110 is fixedly mounted with the first hoist 6, the lower end of the first hoist 6 is respectively connected to the two ends of the horizontal track beam 2, and the horizontal track beam 2 is pin-connected or fixed to the portal frame 1 by inserting or pulling out a pin 9. Disengagement, one or more longitudinal actuators 21 are suspended in the middle of the horizontal track beam 2, the vertical track column 3 is arranged on the outside of the portal frame 1 on one side, the upper ends of a pair of vertical track columns 3 are horizontally connected through a fixed crossbeam 4, the fixed crossbeam 4 is fixedly installed with a second hoist 7, the lower end of the second hoist 7 is connected to the movable crossbeam 5, the transverse actuator 51 is connected to the side of the movable crossbeam 5 by bolts, the movable crossbeam 5 is fixed or disengaged with the vertical track column 3 by inserting or pulling out the pin 9, the transverse support frame 10 is transversely consolidated with the vertical track column 3 and the portal frame 1 on the same side through steel sections, so as to realize a freely adjustable low-cycle repeated load test loading frame.

[0031] The two ends of the horizontal track beam 2 are respectively embedded in the interior of the portal frame 1 at both ends, and the inner groove wall of the vertical column 11 of the portal frame 1 is used as a slide rail. The horizontal track beam 2 is lifted or lowered by the first hoist 6 with the upper cross beam 110 as support to adaptively move up and down, and a roller 52 is provided on the contact surface between the horizontal track beam 2 and the inner groove wall of the vertical column 11.

[0032] The tail end of the longitudinal actuator 21 is suspended and installed on the bottom surface of the horizontal track beam 2, and can be adaptively moved horizontally left and right along the axial direction of the horizontal track beam 2. A pulley or roller is arranged between the upper connecting plate 211 and the lower connecting plate 212 at the tail end of the longitudinal actuator 21 and the horizontal track beam 2.

[0033] The vertical columns 11 of the portal frame 1 are provided with a plurality of bolt holes 8 spaced apart along the height direction, the vertical track columns 3 are provided with a plurality of bolt holes 8 spaced apart along the height direction, and bolt holes 8 are also provided at the corresponding positions at both ends of the horizontal track beam 2 and on the movable cross beam 5, and the bolt holes 8 correspond to the corresponding pins 9.

[0034] The movable crossbeam 5 is located at the lower part of the fixed crossbeam 4, embedded between the two vertical track columns 3, with the inner groove wall of the vertical track column 3 as a slide rail, and the movable crossbeam 5 is adaptively moved up and down by lifting or lowering the fixed crossbeam 4 with the second hoist 7, and rollers 52 are provided on the contact surface between the movable crossbeam 5 and the inner groove wall of the vertical track column 3 to assist in movement.

[0035] The transverse actuator 51 is located at the lower part of the horizontal track beam 2 , and its tail end is fixed to a side surface of the movable cross beam 5 .

[0036] The center lines of the portal frame 1 , a pair of vertical track columns 3 and the transverse support frame 10 are located in the same straight line along the axial direction of the horizontal track beam 2 .

[0037] After the first hoist 6 and the second hoist 7 respectively lift or lower the horizontal track beam 2 and the movable crossbeam 5, the horizontal track beam 2 and the movable crossbeam 5 are respectively pinned and fixed to the portal frame 1 and the vertical track column 3.

[0038] The base 100 is a steel plate, a reinforced concrete plate or a ground foundation that connects the portal frame 1, the vertical track column 3 and the transverse support frame 10 as a whole.

Claims

1. A freely adjustable low-cycle repeated load test loading frame, comprising a portal frame (1), a horizontal track beam (2), a vertical track column (3), a fixed crossbeam (4), a movable crossbeam (5), a first hoist (6), a second hoist (7) and a base (100), It is characterized in that A pair of portal frames (1) and a pair of vertical track columns (3) are vertically mounted and fixed on a base (100); a horizontally arranged upper cross beam (110) is arranged on the top of the portal frame (1) and is laterally connected to the vertical columns (11) on both sides; a first hoist (6) is fixedly mounted on the upper cross beam (110); the lower end of the first hoist (6) is respectively connected to the two ends of the horizontal track beam (2); the horizontal track beam (2) is pin-connected and fixed to or released from the portal frame (1) by inserting or pulling out a pin bolt (9); One or more longitudinal actuators (21) are suspended and installed in the middle of the horizontal track beam (2), the vertical track column (3) is arranged on the outside of the portal frame (1) on one side, the upper ends of a pair of vertical track columns (3) are horizontally connected through a fixed crossbeam (4), the fixed crossbeam (4) is fixedly installed with a second hoist (7), the lower end of the second hoist (7) is connected to the movable crossbeam (5), the transverse actuator (51) is connected to the side of the movable crossbeam (5) by bolts, and the movable crossbeam (5) is fixed by a pin (9). Insert or pull out the pin connection with the vertical track column (3) to fix or disengage, and the transverse support frame (10) is transversely fixed to the vertical track column (3) and the portal frame (1) on the same side through the steel section, so as to realize a freely adjustable low-cycle repeated load test loading frame; the two ends of the horizontal track beam (2) are respectively embedded in the interior of the portal frame (1) at both ends, and the inner groove wall of the vertical column (11) of the portal frame (1) is used as a slide rail, and the first hoist (6) is used to support the upper cross beam (110) to lift. The horizontal track beam (2) is adapted to move up and down adaptively, and a roller (52) is provided on the contact surface between the horizontal track beam (2) and the inner groove wall of the vertical column (11); the tail end of the longitudinal actuator (21) is suspended and installed on the bottom surface of the horizontal track beam (2), and can be adapted to move horizontally left and right along the axial direction of the horizontal track beam (2), and a pulley or roller is provided between the upper connecting plate (211) and the lower connecting plate (212) at the tail end of the longitudinal actuator (21) and the horizontal track beam (2).

2. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features The vertical columns (11) of the portal frame (1) are provided with a plurality of bolt holes (8) at intervals along the height direction, the vertical track columns (3) are provided with a plurality of bolt holes (8) at intervals along the height direction, and bolt holes (8) are also provided at corresponding positions on both ends of the horizontal track beam (2) and the movable cross beam (5), and the bolt holes (8) are matched with corresponding pins (9).

3. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features The movable crossbeam (5) is located at the lower part of the fixed crossbeam (4), embedded between the two vertical track columns (3), and uses the inner groove wall of the vertical track column (3) as a slide rail. The movable crossbeam (5) is lifted or lowered by the second hoist (7) with the fixed crossbeam (4) as support to adaptively move up and down, and rollers (52) are provided on the contact surface between the movable crossbeam (5) and the inner groove wall of the vertical track column (3) to assist in movement.

4. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features The transverse actuator (51) is located at the lower part of the horizontal track beam (2), and its tail end is fixed to a side surface of the movable cross beam (5).

5. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features The center lines of the portal frame (1), a pair of vertical track columns (3) and the transverse support frame (10) are located on the same straight line along the axial direction of the horizontal track beam (2).

6. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features After the first hoist (6) and the second hoist (7) have finished lifting or lowering the horizontal track beam (2) and the movable cross beam (5), the horizontal track beam (2) and the movable cross beam (5) are respectively pin-connected and fixed to the portal frame (1) and the vertical track column (3).

7. A freely adjustable low cycle repeated load test loading frame according to claim 1, Features The base (100) is a steel flat plate, a reinforced concrete flat plate or a ground foundation that connects the portal frame (1), the vertical track column (3) and the transverse support frame (10) into one body.

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