Axial compression test device and test method for steel pipe column with internal pressure and internal support

Abstract

This invention discloses a steel pipe column axial compression testing device and method with internal pressure and internal support, comprising a uniform pressurization component, a steel pipe column, an internal support component, a loading component, a base plate, a cover plate, an inlet pipe, and an outlet pipe. The bottoms of the steel pipe column and the internal support component are connected to the base plate. The internal support component is located inside the steel pipe column and abuts against the inner wall of the steel pipe column. The top of the steel pipe column is connected to the cover plate, and the top surface of the cover plate is connected to the loading component. An external axial loading device is used to apply axial force to the loading component. The loading component and the cover plate are respectively provided with an inlet hole and an outlet hole. The inlet pipe communicates with the interior of the steel pipe column through the inlet hole, and the outlet pipe communicates with the interior of the steel pipe column through the outlet hole. The uniform pressurization component is connected to both the inlet pipe and the outlet pipe and is used to inject water into the steel pipe column to provide lateral pressure. The water pressure inside the steel pipe column is controlled by a pressure stabilizing pump and a flow valve to adjust the magnitude of the lateral pressure on the steel pipe column.

Description

Technical Field

[0001] The invention relates to the technical field of steel pipe column buckling performance testing, and in particular to an axial compression testing device and a testing method for a steel pipe column with internal pressure and internal support. Background Art

[0002] In recent years, steel-concrete composite structures have been widely used in high-rise and super-high-rise buildings due to their superior mechanical properties and seismic energy absorption capacity. Typical component forms include steel tube concrete columns and steel plate concrete composite shear walls, among which steel tube concrete columns are the most widely used in engineering. Domestic and foreign scholars have conducted corresponding theoretical and experimental studies on the bearing capacity of steel tube concrete columns with various cross-sectional forms. Nowadays, high-strength steel and high-strength concrete have also begun to be used in steel tube concrete structures. However, the emergence of high-strength materials will inevitably bring about changes in the cross-sectional size of components, such as reduced steel tube wall thickness and increased width. These changes have made the width-to-thickness ratio of the steel plate on the outside of the steel tube concrete increasingly larger, and the problem of local buckling of the steel plate has become increasingly prominent, and has begun to attract the attention of engineering personnel. In terms of engineering economy, steel-concrete composite components generally require that the mechanical properties of both steel and concrete materials can be fully utilized during the design process, and steel must be able to fully utilize its yield strength. In terms of structural safety, the emergence of local buckling of steel plates will cause premature damage to components or even overall failure, causing irreparable losses and disasters. Therefore, in the context of engineering economy and structural safety, it is necessary to study the local buckling of composite structural steel plates. In-depth research on the local buckling characteristics and buckling modes of steel plates and taking targeted measures to avoid or delay the occurrence of local buckling of steel plates can not only produce good economic benefits, but also have important significance for promoting the development and application of steel-concrete composite structures and thin-walled steel structures in engineering.

[0003] Nowadays, scholars at home and abroad have begun to study the local buckling performance of steel plates in steel tube concrete columns. The main research methods are limited to theoretical research and finite element numerical research, and certain research results have been achieved. However, in these existing studies, they are basically limited to the theoretical stage and lack experimental research results for demonstration. The theoretical model and numerical model proposed by the researchers cannot be verified with the experimental data, and the theoretical research cannot be further improved. The reason is that there is a lack of special experimental equipment for studying the local buckling performance of steel tube concrete and steel plates at home and abroad. This problem makes it difficult for researchers to carry out relevant experimental research when studying the local buckling performance of steel tubes, and it is impossible to obtain sufficient variable parameter test results to support and improve the theory, which directly restricts the research progress of steel-concrete composite structures and local buckling performance of steel structures.

[0004] Therefore, it is very necessary to develop a test device for the local buckling performance of steel plates in steel tube concrete. Studies have found that the steel plate in the middle of the steel tube concrete is very prone to local buckling of varying degrees during loading. During the stress process, the concrete not only plays a rigid constraint role, but also pushes the outer steel plate in lateral deformation. At present, the relevant research on local buckling of steel plates has not quantitatively considered the adverse effects of lateral expansion of concrete. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a steel pipe column axial compression test device with internal pressure and internal support. The device applies uniform lateral force and rigid support to the inside of the steel pipe column to study the local buckling performance of the steel pipe column under unilateral constraint under different lateral forces and axial pressures, and can simulate to a certain extent the lateral extrusion effect of the steel pipe column on the steel pipe column by the concrete filled in the steel pipe column.

[0006] Another object of the present invention is to provide a testing method for the above-mentioned steel pipe column axial compression testing device with internal pressure and internal support.

[0007] The technical solution of the present invention is: an axial compression test device for a steel pipe column with internal pressure and internal support, comprising a uniform pressure component, a steel pipe column, an internal support component, a loading component, a bottom plate, a cover plate, a water inlet pipe and a water outlet pipe;

[0008] The bottoms of the steel pipe column and the internal support assembly are both connected to the base plate. The internal support assembly is located inside the steel pipe column and abuts against the inner wall of the steel pipe column. The top of the steel pipe column is connected to the cover plate. The top surface of the cover plate is connected to the loading assembly. The external axial loading device is used to apply axial force to the loading assembly. The loading assembly and the cover plate are respectively provided with water inlet holes and water outlet holes. The water inlet pipe is connected to the interior of the steel pipe column through the water inlet hole. The water outlet pipe is connected to the interior of the steel pipe column through the water outlet hole. The uniform pressurizing assembly is respectively connected to the water inlet pipe and the water outlet pipe. The uniform pressurizing assembly is used to inject water into the steel pipe column to provide lateral pressure for the steel pipe column.

[0009] Furthermore, the inner support assembly includes an inner steel ring, a corner steel plate and a middle steel plate, the corner steel plate and the middle steel plate are connected to the inner steel ring at intervals, the corner steel plate abuts the corner area of ​​the steel pipe column, the middle steel plate abuts the middle area of ​​the steel pipe column, and the bottoms of the corner steel plate and the middle steel plate are respectively connected to the bottom plate. The steel pipe column is supported by the inner support assembly to simulate the rigid medium effect of concrete to prevent the steel pipe column from partially buckling inward during the test.

[0010] Furthermore, the uniform pressurization component includes a water tank and a pressure-stabilizing pump, the water inlet pipe and the water outlet pipe are respectively connected to the water tank, the pressure-stabilizing pump is connected between the water tank and the water inlet pipe, the water inlet pipe is provided with a digital pressure gauge, the water inlet pipe and the water outlet pipe are respectively provided with flow valves, and the digital pressure gauge is used to check the water pressure in the water inlet pipe. The steel pipe column is uniformly pressurized by water injection, which has low cost, high safety factor and is easy to operate.

[0011] Furthermore, the loading assembly includes an upper pad, a lower pad and a stiffening rib, the lower pad is connected to the top surface of the cover plate, the upper and lower ends of the stiffening rib are connected to the upper pad and the lower pad respectively, and the water inlet pipe and the water outlet pipe are both located between the upper pad and the lower pad. The space between the upper pad and the lower pad is supported by arranging the inner stiffening rib and the side stiffening rib, the structural strength between the upper and lower pads is enhanced, and the upper and lower pads are prevented from being deformed when the axial loading device applies axial pressure to the upper and lower pads, thereby damaging the water inlet pipe and the water outlet pipe.

[0012] Furthermore, the bottom plate is provided with two clearance grooves, one of which is connected to the water inlet hole, and the other is connected to the water outlet hole, and the width of the clearance groove is slightly larger than the width of the water inlet pipe and the water outlet pipe. By providing the clearance groove, the water inlet pipe and the water outlet pipe are given way, which facilitates the connection of the test device.

[0013] Furthermore, the stiffening ribs include inner stiffening ribs and side stiffening ribs, the inner stiffening ribs are cross-shaped, the outer sides of the inner stiffening ribs are respectively vertically connected to the side stiffening ribs, and the clearance grooves are located between two adjacent side stiffening ribs.

[0014] Furthermore, it also includes upper stiffening ribs and lower stiffening ribs, wherein the upper stiffening ribs connect the outer wall of the steel pipe column and the bottom surface of the cover plate, and the lower stiffening ribs connect the outer wall of the steel pipe column and the top surface of the bottom plate. By providing the upper stiffening ribs and the lower stiffening ribs, the connection strength between the steel pipe column and the cover plate and the bottom plate is enhanced.

[0015] Another technical solution of the present invention is: the test method of the above-mentioned steel pipe column axial compression test device with internal pressure and internal support comprises the following steps:

[0016] Step S1: using an inner support assembly to support the middle area and corner area of ​​the inner wall of the steel pipe column. The inner support assembly is used to support the steel pipe column during the test, simulating the rigid medium effect of concrete to prevent the steel pipe column from partially buckling inward. The bottom of the inner support assembly and the steel pipe column are welded to the bottom plate respectively.

[0017] Step S2: welding the cover plate to the top of the steel pipe column;

[0018] Step S3: installing the loading assembly to the top surface of the cover plate, the water inlet pipe and the water outlet pipe are connected to the inside of the steel pipe column through the water inlet hole and the water outlet hole on the loading assembly and the cover plate respectively, and the external axial loading device applies axial pressure to the loading assembly;

[0019] Step S4: The uniform pressurizing component injects water into the steel pipe column through the water inlet pipe to provide lateral pressure for the steel pipe column. By controlling the water pressure, the lateral pressure on the steel pipe column can be adjusted.

[0020] The working principle of the steel pipe column axial pressure testing device with internal pressure and internal support of the present invention is as follows: when pressurizing, the flow valve on the water outlet pipe is closed, and the steel pipe column is injected with water and pressurized through the water inlet pipe to provide lateral pressure for the steel pipe column. The digital pressure gauge is used to check the pressure in the water inlet pipe, the pressure-stabilizing pump controls the water supply pressure, and the flow valve on the water inlet pipe is adjusted to adjust the pressure in the steel pipe column, so as to adjust the lateral pressure on the steel pipe column. The flow valve on the water outlet pipe is used to reduce the pressure in the steel pipe column and remove the air in the steel pipe column.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The steel pipe column axial compression test device with internal pressure and internal support of the present invention adopts the steel pipe column as the main load-bearing component and can be used to study the load-bearing performance of steel pipe columns of various materials under the combined action of axial force and lateral forces of different sizes.

[0023] The axial pressure testing device for a steel pipe column with internal pressure and internal support of the present invention applies lateral pressure to the interior of the steel pipe column by injecting water into the steel pipe column to increase pressure. The digital pressure gauge can observe the internal pressure of the steel pipe column in real time. The water pressure in the steel pipe column is controlled by a pressure-stabilizing pump and a flow valve to adjust the lateral pressure on the steel pipe column.

[0024] The steel pipe column axial compression test device with internal pressure and internal support of the present invention can effectively provide rigid support to the inner side of the steel pipe column by arranging an internal support component in the steel pipe column, so that the actual force of the steel pipe column is more consistent with the force of the steel pipe concrete column. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the assembly of the steel pipe column and the loading assembly of the present invention.

[0026] Figure 2 It is a schematic diagram of the assembly of the inner support assembly and the base plate of the present invention.

[0027] Figure 3 for Figure 1 Section view along line AA.

[0028] Figure 4 for Figure 1 Section view along line BB.

[0029] Figure 5 for Figure 3 Cross-sectional view along line CC.

[0030] Figure 6It is a schematic diagram of the overall structure of the test device of the present invention.

[0031] Steel pipe column 1, base plate 2, cover plate 3, water inlet pipe 4, water outlet pipe 5, upper stiffening rib 6, lower stiffening rib 7, inner steel bar ring 8, corner steel plate 9, middle steel plate 10, upper pad 11, lower pad 12, make way groove 13, inner stiffening rib 14, side stiffening rib 15, digital pressure gauge 16, flow valve 17. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0033] Example

[0034] like Figure 1 and Figure 6 As shown, this embodiment provides an axial compression test device for a steel pipe column with internal pressure and internal support, including a uniform pressure component, a steel pipe column 1, an internal support component, a loading component, a base plate 2, a cover plate 3, an inlet pipe 4, an outlet pipe 5, an upper stiffening rib 6 and a lower stiffening rib 7.

[0035] like Figure 2 and Figure 4 As shown, the bottom of the steel pipe column and the inner support assembly are both connected to the bottom plate, the inner support assembly is located inside the steel pipe column, the inner support assembly abuts the inner wall of the steel pipe column, the inner support assembly includes an inner steel reinforcing ring 8, a corner steel plate 9 and a middle steel plate 10, the corner steel plate and the middle steel plate are connected to the inner steel reinforcing ring at intervals, and multiple inner steel reinforcing rings are distributed along the height direction of the corner steel plate and the middle steel plate, the corner steel plate abuts the corner area of ​​the steel pipe column, the middle steel plate abuts the middle area of ​​the steel pipe column, and the bottoms of the corner steel plate and the middle steel plate are respectively connected to the bottom plate. The steel pipe column is supported by the inner support assembly to simulate the rigid medium effect of concrete to prevent the steel pipe column from buckling locally inward during the test.

[0036] like Figure 1 , Figure 5 and Figure 6 As shown, the top of the steel pipe column is welded to the cover plate, the top surface of the cover plate is connected to the loading assembly, the external axial loading device is used to apply axial force to the loading assembly, the loading assembly and the cover plate are respectively provided with a water inlet hole and a water outlet hole, the water inlet pipe is connected to the inside of the steel pipe column through the water inlet hole, and the water outlet pipe is connected to the inside of the steel pipe column through the water outlet hole; Figure 1 and Figure 3As shown, the loading assembly includes an upper pad 11, a lower pad 12 and a stiffening rib. The lower pad is connected to the top surface of the cover plate. The upper and lower ends of the stiffening rib are connected to the upper pad and the lower pad respectively. The water inlet pipe and the water outlet pipe are located between the upper pad and the lower pad. The space between the upper pad and the lower pad is supported by arranging inner stiffening ribs and side stiffening ribs to enhance the structural strength between the upper and lower pads, and prevent the upper pad and the lower pad from deforming when the axial loading device applies axial pressure to the upper pad and the lower pad, thereby damaging the water inlet pipe and the water outlet pipe. Figure 3 As shown, the lower pad is provided with two clearance grooves 13, one of which is connected to the water inlet hole, and the other is connected to the water outlet hole. The width of the clearance groove is slightly larger than the width of the water inlet pipe and the water outlet pipe. By setting the clearance groove, the water inlet pipe and the water outlet pipe are given way, which facilitates the connection of the test device. The stiffening ribs include inner stiffening ribs 14 and side stiffening ribs 15. The inner stiffening ribs are cross-shaped, and the outer sides of the inner stiffening ribs are respectively vertically connected to the side stiffening ribs, and the clearance grooves are located between two adjacent side stiffening ribs.

[0037] like Figure 1 As shown, the upper stiffening rib connects the outer wall of the steel pipe column and the bottom surface of the cover plate, and the lower stiffening rib connects the outer wall of the steel pipe column and the top surface of the bottom plate. By setting the upper stiffening rib and the lower stiffening rib, the connection strength between the steel pipe column and the cover plate and the bottom plate is enhanced.

[0038] like Figure 6 As shown, the uniform pressurization assembly is connected to the water inlet pipe and the water outlet pipe respectively, and the uniform pressurization assembly is used to inject water into the steel pipe column to provide lateral pressure for the steel pipe column; the uniform pressurization assembly includes a water tank and a pressure-stabilizing pump, the water inlet pipe and the water outlet pipe are connected to the water tank respectively, the pressure-stabilizing pump is connected between the water tank and the water inlet pipe, the water inlet pipe is provided with a digital pressure gauge 16, the water inlet pipe and the water outlet pipe are provided with flow valves 17 respectively, and the digital pressure gauge is used to check the water pressure in the water inlet pipe. The steel pipe column is uniformly pressurized by water injection, which is low in cost, high in safety factor, and easy to operate.

[0039] The test method of the above-mentioned steel pipe column axial compression test device with internal pressure and internal support comprises the following steps:

[0040] Step S1: using an inner support assembly to support the middle area and corner area of ​​the inner wall of the steel pipe column. The inner support assembly is used to support the steel pipe column during the test, simulating the rigid medium effect of concrete to prevent the steel pipe column from partially buckling inward. The bottom of the inner support assembly and the steel pipe column are welded to the bottom plate respectively.

[0041] Step S2: welding the cover plate to the top of the steel pipe column;

[0042] Step S3: installing the loading assembly to the top surface of the cover plate, the water inlet pipe and the water outlet pipe are connected to the inside of the steel pipe column through the water inlet hole and the water outlet hole on the loading assembly and the cover plate respectively, and the external axial loading device applies axial pressure to the loading assembly;

[0043] Step S4: The uniform pressurizing component injects water into the steel pipe column through the water inlet pipe to provide lateral pressure for the steel pipe column. By controlling the water pressure, the lateral pressure on the steel pipe column can be adjusted.

[0044] The working principle of the steel pipe column axial pressure testing device with internal pressure and internal support of the present invention is as follows: when pressurizing, the flow valve on the water outlet pipe is closed, and the steel pipe column is injected with water and pressurized through the water inlet pipe to provide lateral pressure for the steel pipe column. The digital pressure gauge is used to check the pressure in the water inlet pipe, the pressure-stabilizing pump controls the water supply pressure, and the flow valve on the water inlet pipe is adjusted to adjust the pressure in the steel pipe column, so as to adjust the lateral pressure on the steel pipe column. The flow valve on the water outlet pipe is used to reduce the pressure in the steel pipe column and remove the air in the steel pipe column.

[0045] As described above, the present invention can be better implemented. The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope of protection required by the claims of the present invention.

Claims

1. An axial compression test device for a steel pipe column with internal pressure and internal support, characterized in that: It includes a uniform pressurization component, a steel pipe column, an inner support component, a loading component, a base plate, a cover plate, a water inlet pipe and a water outlet pipe; The bottoms of the steel pipe column and the inner support assembly are both connected to the bottom plate, the inner support assembly is located inside the steel pipe column, the inner support assembly abuts against the inner wall of the steel pipe column, the top of the steel pipe column is connected to the cover plate, the top surface of the cover plate is connected to the loading assembly, the external axial loading device is used to apply axial force to the loading assembly, the loading assembly and the cover plate are respectively provided with a water inlet hole and a water outlet hole, the water inlet pipe is connected to the inside of the steel pipe column through the water inlet hole, the water outlet pipe is connected to the inside of the steel pipe column through the water outlet hole, the uniform pressurizing assembly is respectively connected to the water inlet pipe and the water outlet pipe, and the uniform pressurizing assembly is used to inject water into the steel pipe column to provide lateral pressure for the steel pipe column; The inner support assembly includes an inner steel bar ring, a corner steel plate and a middle steel plate. The corner steel plate and the middle steel plate are connected to the inner steel bar ring at intervals. Multiple inner steel bar rings are distributed along the height direction of the corner steel plate and the middle steel plate. The corner steel plate abuts the corner area of ​​the steel pipe column, the middle steel plate abuts the middle area of ​​the steel pipe column, and the bottom of the corner steel plate and the middle steel plate are respectively connected to the bottom plate.

2. The axial compression test device for steel pipe columns with internal pressure and internal support according to claim 1, characterized in that: The uniform pressurizing component includes a water tank and a pressure-stabilizing pump. The water inlet pipe and the water outlet pipe are respectively connected to the water tank. The pressure-stabilizing pump is connected between the water tank and the water inlet pipe. The water inlet pipe is provided with a digital pressure gauge. The water inlet pipe and the water outlet pipe are respectively provided with flow valves. The digital pressure gauge is used to check the water pressure in the water inlet pipe.

3. The axial compression test device for steel pipe columns with internal pressure and internal support according to claim 1, characterized in that: The loading assembly includes an upper pad, a lower pad and a stiffening rib. The lower pad is connected to the top surface of the cover plate. The upper and lower ends of the stiffening rib are respectively connected to the upper pad and the lower pad. The water inlet pipe and the water outlet pipe are both located between the upper pad and the lower pad.

4. The axial compression test device for steel pipe columns with internal pressure and internal support according to claim 3, characterized in that: The lower pad is provided with two paving grooves, one of which is connected to the water inlet hole and the other is connected to the water outlet hole. The width of the paving groove is slightly larger than the width of the water inlet pipe and the water outlet pipe.

5. The axial compression test device for steel pipe columns with internal pressure and internal support according to claim 4, characterized in that: The stiffening ribs include inner stiffening ribs and side stiffening ribs. The inner stiffening ribs are cross-shaped. The outer sides of the inner stiffening ribs are respectively vertically connected to the side stiffening ribs. The clearance grooves are located between two adjacent side stiffening ribs.

6. The axial compression test device for steel pipe columns with internal pressure and internal support according to claim 1, characterized in that: It also includes upper stiffening ribs and lower stiffening ribs, wherein the upper stiffening ribs connect the outer wall of the steel pipe column and the bottom surface of the cover plate, and the lower stiffening ribs connect the outer wall of the steel pipe column and the top surface of the bottom plate.

7. A test method using the steel pipe column axial compression test device with internal pressure and internal support as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1: using an inner support assembly to support the middle area and corner area of ​​the inner wall of the steel pipe column. The inner support assembly is used to support the steel pipe column during the test, simulating the rigid medium effect of concrete to prevent the steel pipe column from partially buckling inward. The bottom of the inner support assembly and the steel pipe column are welded to the bottom plate respectively. Step S2: welding the cover plate to the top of the steel pipe column; Step S3: installing the loading assembly to the top surface of the cover plate, the water inlet pipe and the water outlet pipe are connected to the inside of the steel pipe column through the water inlet hole and the water outlet hole on the loading assembly and the cover plate respectively, and the external axial loading device applies axial pressure to the loading assembly; Step S4: The uniform pressurizing component injects water into the steel pipe column through the water inlet pipe to provide lateral pressure for the steel pipe column. By controlling the water pressure, the lateral pressure on the steel pipe column can be adjusted.

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