A wall component out-of-plane force performance test device and test method

Abstract

A device and method for testing the out-of-plane force performance of a wall component, the device consists of a frame-type reaction frame, an airbag, a reaction plate, a load sensor assembly and a displacement sensor; the reaction plate is located inside the reaction frame, the airbag is located between the wall component and the reaction plate, and the reaction plate is connected to the reaction frame through the load sensor assembly; one end of the displacement sensor is in contact with the wall component, and the other end is fixedly connected to the displacement sensor bracket. The test steps include assembling the experimental device, adjusting the reaction plate to be parallel to the surface of the wall component; adjusting the airbag to fit the surface of the wall component; and loading test. This invention improves the accuracy of the test data by adjusting the reaction plate to be parallel to the surface of the wall component and adjusting the airbag to fit the surface of the wall component through the load sensor assembly on the basis of retaining the advantages of the prior art.

Description

Technical Field

[0001] The invention relates to a civil engineering structure performance test, in particular to an out-of-plane force performance test device and a test method for a wall component. Background Art

[0002] Previous earthquake disasters have shown that under the action of earthquakes, the wall components in building structures will experience serious out-of-plane collapse, which not only damages the use function of the building, but also incurs huge repair costs for the wall components after the earthquake. More seriously, the collapse and fall of the wall will endanger people's lives and property safety and block the rescue route. Therefore, it is necessary to study the out-of-plane force performance of wall components, and the out-of-plane force performance test device of wall components is an important means of this research.

[0003] Existing out-of-plane force performance test devices for wall components are mainly divided into earthquake simulation vibration tables, hydraulic actuator loading test devices and air bag loading test devices.

[0004] Although the earthquake simulation shaking table can simulate the stress process of components under the action of real earthquakes, it cannot accurately grasp the out-of-plane bearing capacity and deformation capacity of wall components. In addition, the test cost is high and it is difficult to promote.

[0005] Under the action of earthquake, the wall is affected by the inertia force of the wall caused by the earthquake. Existing studies have shown that it is reasonable to simulate this inertia force by applying a uniform load on the wall surface. Although the hydraulic actuator loading test device can realize cyclic reciprocating loading through displacement control, it transmits concentrated loads to the wall and cannot simulate the real uniform load; the airbag loading test device can better simulate the real uniform load.

[0006] The existing airbag loading test device, taking the "An airbag loading test device outside the plane of a structural member" disclosed in the patent application CN109211549A as an example, is composed of a movable reaction frame, an airbag, a reaction plate and a displacement measuring instrument. The device relies on the airbag to uniformly load the tested wall member through the reaction plate, and the applied load is read by the air pressure sensor. The deformation of the wall member is measured by the displacement measuring instrument installed between the wall member and the bracket. The device has the advantages of applying a uniform load to the plane of the wall member through the airbag to truly simulate the earthquake effect, and the test does not require a large reaction wall through the self-reaction force balance system. However, it is found that there are still two technical problems in actual use: ① Because the edge of the surface of the airbag has a certain curvature after being inflated, when it contacts the surface of the wall member, the edge cannot be guaranteed to be completely in contact with the surface of the wall member. At this time, if the size of the airbag is designed to be larger than the size of the wall surface (so that the inflated airbag can be completely in contact with the surface of the wall member), it is not advisable because the airbag will load the frame around the wall at the same time. The purpose of the wall component loading test is to obtain its out-of-plane load-displacement curve. The load data comes from the product of air pressure and wall surface area. If the airbag does not fit the wall component surface well, this product will be greater than the actual load on the wall specimen, thus affecting the accuracy of the test results. In addition, for large-sized wall components, due to the large wall surface, multiple airbags are usually used to cover the wall surface at the same time. At this time, when each airbag is inflated, gaps will be generated at the edges that contact each other, resulting in poor fit between the airbag and the wall component surface. This situation is difficult to detect by observation because it does not occur at the edge of the wall, which also affects the accuracy of the test results. ② When the airbag is loaded, a self-made reaction plate is used instead of the reaction wall to form a self-reaction balance system. At this time, the airbag is supported by the reaction plate. If the reaction plate cannot remain parallel to the wall component surface, the airbag will transfer load unevenly to various parts of the wall surface, which also affects the accuracy of the test results. Summary of the invention

[0007] In view of the above technical problems existing in the existing airbag loading test device, the present invention provides a wall component out-of-plane force performance test device and a test method to improve the accuracy of the test results.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] A wall component out-of-plane force performance test device, comprising an air bag, a reaction frame, a reaction plate, a load sensor assembly and a displacement sensor;

[0010] The airbag is a single airbag or multiple airbags close to each other (multiple airbags are suitable for large-sized wall components);

[0011] The reaction frame is a rectangular parallelepiped or cubic (depending on the shape of the wall component) frame structure, and a group of reaction beams evenly spaced up and down are installed between the two frame columns at the rear side of the reaction frame;

[0012] The reaction plate is composed of a steel tube grid frame (302) covered with plywood on one side, and a group of universal rollers are arranged at the bottom of the steel tube grid frame; the reaction plate is located inside the reaction frame, the airbag is located between the wall component and the plywood, and the reaction plate is connected to the reaction beam at the rear side of the reaction frame through a group of load sensor components respectively corresponding to the reaction beam at the rear side of the reaction frame and arranged in intervals up and down;

[0013] The load sensor assembly comprises an "S"-shaped load sensor and a front connector and a rear connector which are threadedly connected to both ends of the load sensor (for adjusting the parallelism between the reaction plate and the wall member); the front connector is connected to the steel pipe grid through a gasket, and the rear connector is connected to the reaction beam (206) of the reaction frame;

[0014] The displacement sensors are horizontally arranged at even intervals on the back side of the wall component, one end of the displacement sensor is in contact with the wall component, and the other end is fixedly connected to a displacement sensor bracket standing on the ground.

[0015] The method for conducting an out-of-plane force performance test of a wall component using the above-mentioned out-of-plane force performance test device of the wall component comprises the following steps:

[0016] Step 1: Assemble the test device

[0017] First, the wall component (test piece) is fixed on the frame on the front side of the reaction frame by masonry or bolt connection; then, an air bag is placed between the wall component and the reaction plate; and then, the displacement sensor bracket is moved so that the end of the displacement sensor contacts the surface of the wall component;

[0018] Step 2: Adjust the reaction plate to be parallel to the surface of the wall component

[0019] The airbag is inflated and loaded (when there are multiple airbags, they are inflated at the same time at the same inflation rate), and the air pressure inside the airbag is measured by an air pressure sensor (when there are multiple airbags, each airbag is equipped with an air pressure sensor). When the air pressure reaches 20% of the estimated value of the cracking load of the wall component, the loading is stopped; the values ​​measured by multiple load sensors are compared with each other. If they are basically the same, it means that the reaction plate is parallel to the surface of the wall component, and the test proceeds to the next step; if there are large differences in the values ​​measured by multiple load sensors, it means that the reaction plate is not parallel enough to the surface of the wall component. At this time, the airbag is depressurized to zero, and the length of individual load sensor components is adjusted by screwing the load sensor, so as to adjust the position of the reaction plate in space so that it is parallel to the surface of the wall component, and then the airbag is re-inflated until the air pressure of the airbag is 20% of the estimated value of the cracking load of the wall component, and the loading is stopped, and the test proceeds to the next step;

[0020] Step 3: Adjust the airbag to fit the surface of the wall component

[0021] After the reaction plate is parallel to the surface of the wall component, divide the value measured by the load sensor by the air bag pressure measured by the air pressure sensor, and compare the calculated result with the surface area of ​​the wall component. If they are basically the same, it means that the air bag and the surface of the wall component are well attached, and the air bag is depressurized to zero, and the test proceeds to the next step; if the calculated result is significantly smaller than the surface area of ​​the wall component, it means that the air bag and the surface of the wall component are not well attached, and the air bag is depressurized to zero at this time, and the position of the air bag in the plane is adjusted (for multiple air bags, they are close to each other after deflation to reduce the gap between them after inflation), and then the air bag is inflated until the air pressure reaches 20% of the estimated value of the cracking load of the wall component and the loading is stopped, and the above calculation is repeated until the calculated result is basically the same as the surface area of ​​the wall component, and then the air bag is depressurized to zero, and the test proceeds to the next step;

[0022] Step 4: Loading test

[0023] The airbags are continuously inflated (multiple airbags are inflated at the same rate at the same time) until the wall components are destroyed. The values ​​of the air pressure sensor and displacement sensor during the deformation of the wall components until destruction are recorded to analyze the out-of-plane force performance of the wall components.

[0024] Beneficial effects of the present invention:

[0025] The present invention retains the advantages of the prior art (the test device disclosed in the CN109211549A patent application), namely, applying a uniformly distributed load to the plane of the wall component through the airbag to simulate the real earthquake effect; the self-reaction force balance system makes the test not require a large reaction wall and is not restricted by the test conditions; the displacement sensor bracket is used to fix the displacement sensor in the early stage of the test, and is used to intercept the fragments of the wall collapse when the test piece is damaged in the later stage of the test, so as to ensure the safety of the test and the cleanliness of the test environment. On this basis, the present invention can adjust the reaction plate to be parallel to the surface of the wall component through the load sensor installed between the reaction plate and the reaction frame; adjust the airbag to fit well with the surface of the wall component, thereby improving the accuracy of the test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional schematic diagram of the out-of-plane force performance test device of the wall component of the present invention (excluding the displacement sensor and its bracket);

[0027] Figure 2 For along Figure 1 Middle AA section view (with displacement sensor and its bracket added);

[0028] Figure 3 for Figure 1 and Figure 2 The three-dimensional schematic diagram of the structure of the middle reaction frame;

[0029] Figure 4 for Figure 1 and Figure 2 Schematic diagram of the structure of the center reaction plate;

[0030] Figure 5 for Figure 1 and Figure 2 Schematic diagram of the structure of the medium load sensor assembly.

[0031] In the figure: 1-airbag, 2-reaction frame, 201-frame top cross beam, 202-frame top longitudinal beam, 203-frame column, 204-frame bottom cross beam, 205-frame bottom longitudinal beam, 206-reaction cross beam, 3-reaction plate, 301-plywood, 302-steel pipe grid, 303-universal roller, 4-load sensor assembly, 401-load sensor, 402-rear connector, 403-front connector, 404-gasket, 5-wall component, 6-displacement sensor, 7-displacement sensor bracket. DETAILED DESCRIPTION

[0032] The out-of-plane force performance testing device for wall components of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] Combination Figure 1 and Figure 2, an embodiment of the out-of-plane force performance test device of a wall component of the present invention comprises an airbag 1, a reaction frame 2, a reaction plate 3, a load sensor assembly 4 and a displacement sensor 6; the airbag is a single airbag.

[0034] like Figure 3 As shown, the reaction frame 2 is a rectangular frame structure, including four frame columns 203; two frame top cross beams 201 and a frame top longitudinal beam 202 fixedly connected to the upper ends of the frame columns 203; two frame bottom cross beams 204 and a frame bottom longitudinal beam 205 fixedly connected to the lower ends of the frame columns 203; three reaction beams 206 evenly spaced up and down are installed between the two frame columns 203 on the rear side of the reaction frame 2; the entire frame is made of steel.

[0035] like Figure 4 As shown, the reaction plate 3 is composed of a steel tube grid 302 covered with a plywood 301 on one side, and two universal rollers 303 are installed at the bottom of the steel tube grid 302; Figure 1 As shown, the reaction plate 3 is located inside the reaction frame 2; Figure 2 As shown, the airbag 1 is located between the wall component 5 and the plywood 301, and the reaction plate 3 is connected to the reaction beam 206 of the reaction frame through three load sensor assemblies 4 corresponding to the reaction beam 206 on the rear side of the reaction frame 2 and arranged in an upper and lower interval.

[0036] like Figure 5 As shown, the load sensor assembly 4 includes an "S"-shaped load sensor 401 and a front connector 403 and a rear connector 402 which are threadedly connected to both ends of the load sensor 401 (not shown); the front connector 403 is welded to the steel pipe grid 302 through a gasket 404, and the rear connector 402 is welded to the reaction beam 206 of the reaction frame 2; the length of the load sensor assembly 4 can be adjusted by screwing the load sensor 401, thereby adjusting the parallelism of the reaction plate 3 and the wall member 5.

[0037] like Figure 2 As shown, the displacement sensors 6 are evenly arranged horizontally on the back side of the wall component 5, one end of the displacement sensor 6 is in contact with the wall component 5, and the other end is fixedly connected to a displacement sensor bracket 7 standing on the ground.

Claims

1. A method for performing an out-of-plane force performance test on a wall component using an out-of-plane force performance test device for a wall component, characterized in that: The out-of-plane force performance test device for a wall component comprises an air bag (1), a reaction frame (2), a reaction plate (3), a load sensor assembly (4) and a displacement sensor (6); The airbag (1) is a single airbag or a plurality of airbags close to each other; The reaction frame (2) is a rectangular parallelepiped or cubic frame structure, and a group of reaction beams (206) evenly spaced vertically are installed between two frame columns (203) at the rear side of the reaction frame (2); The reaction plate (3) is composed of a steel tube grid (302) covered with a plywood (301) on one side, and a group of universal rollers (303) are arranged at the bottom of the steel tube grid (302); the reaction plate (3) is located inside the reaction frame (2), the airbag (1) is located between the wall component (5) and the plywood (301), and the reaction plate (3) is connected to the reaction beam (206) on the rear side of the reaction frame through a group of load sensor components (4) respectively corresponding to the reaction beam (206) on the rear side of the reaction frame and arranged in an upper and lower interval; The load sensor assembly (4) comprises an "S"-shaped load sensor (401) and a front connector (403) and a rear connector (402) threadedly connected to both ends of the load sensor (401); the front connector (403) is connected to the steel pipe grid (302) via a gasket (404), and the rear connector (402) is connected to the reaction beam (206) of the reaction frame (2); The displacement sensors (6) are arranged horizontally and evenly spaced on the back side of the wall component (5); one end of the displacement sensor (6) is in contact with the wall component (5), and the other end is fixedly connected to a displacement sensor bracket (7) standing on the ground; The method for conducting an out-of-plane force performance test of a wall component using the out-of-plane force performance test device of the wall component comprises the following steps: Step 1: Assemble the test device First, the wall component is fixed to the frame on the front side of the reaction frame by masonry or bolt connection; then, an air bag is placed between the wall component and the reaction plate; and then, the displacement sensor bracket is moved so that the end of the displacement sensor contacts the surface of the wall component; Step 2: Adjust the reaction plate to be parallel to the surface of the wall component The airbag is inflated and loaded, and the air pressure inside the airbag is measured by an air pressure sensor. When the air pressure reaches 20% of the estimated value of the cracking load of the wall component, the loading is stopped; the values ​​measured by multiple load sensors are compared with each other. If they are basically the same, it means that the reaction plate is parallel to the surface of the wall component, and the test proceeds to the next step; if there is a large difference in the values ​​measured by multiple load sensors, it means that the reaction plate is not parallel enough to the surface of the wall component. At this time, the airbag is depressurized to zero, and the length of individual load sensor components is adjusted by screwing the load sensor, so as to adjust the position of the reaction plate in space so that it is parallel to the surface of the wall component, and then the airbag is re-inflated until the air pressure of the airbag is 20% of the estimated value of the cracking load of the wall component, and the loading is stopped, and the test proceeds to the next step; Step 3: Adjust the airbag to fit the surface of the wall component After the reaction plate is parallel to the surface of the wall component, divide the value measured by the load sensor by the air bag pressure measured by the air pressure sensor, and compare the calculated result with the surface area of ​​the wall component. If they are basically the same, it means that the air bag and the surface of the wall component are well fitted, and the air bag is depressurized to zero, and the test proceeds to the next step; if the calculated result is significantly smaller than the surface area of ​​the wall component, it means that the air bag and the surface of the wall component are not well fitted, and the air bag is depressurized to zero at this time, and the position of the air bag in the plane is adjusted, and the air bag is inflated until the air pressure reaches 20% of the estimated value of the cracking load of the wall component, and the loading is stopped, and the above calculation is repeated until the calculated result is basically the same as the surface area of ​​the wall component, and then the air bag is depressurized to zero, and the test proceeds to the next step; Step 4: Loading test The airbag is continuously inflated until the wall component is destroyed. The values ​​of the air pressure sensor and displacement sensor are recorded during the deformation of the wall component until it is destroyed, which is used to analyze the out-of-plane force performance of the wall component.

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