Stress-strain constitutive test structure

Abstract

The invention provides a stress-strain constitutive test structure, relates to the technical field of concrete mechanical property test, and is used for testing a concrete filled steel tube combination column of which the center is filled with inner filler stone. Comprising a first steel pipe, a second steel pipe, a third steel pipe, a shaft penetrating type force sensor and a circular force sensor, the circular force sensor is used for testing the concrete-filled steel tube combination column of filler stone in the center, it is guaranteed that all components in the concrete-filled steel tube combination column are stressed at the same time and have the same axial deformation through connection of the steel pipes, and the shaft penetrating type force sensor is arranged on concrete. And the circular force sensor is arranged on the inner filler stone, so that load-displacement curves borne by the concrete and the filler stone in the concrete-filled steel tube composite column can be directly and accurately measured respectively, and the defect that only the overall load-displacement relationship of the concrete-filled steel tube composite structure can be obtained by a traditional test method is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete mechanical property testing, and in particular to a stress-strain constitutive testing structure. Background Art

[0002] Steel tube concrete composite structure can give full play to the advantages of steel and concrete, and is widely used for its high bearing capacity and excellent seismic performance. At the same time, in order to continuously improve the performance of steel tube concrete structure, more constraints, internal structures and high-performance concrete are added to obtain a structural form with better performance.

[0003] The SCFST structure is composed of steel tubes, concrete, and internal filling stones. The use of large internal filling stones reduces the amount of concrete used in the structure, reducing carbon emissions. And under the constraints of steel tube concrete, the internal filling stones are in a three-way compression state, and their strength can be fully exerted, which significantly improves the structural bearing capacity and further improves the structure's earthquake resistance and disaster prevention capabilities.

[0004] However, under compression, conventional test methods can only obtain the overall load-displacement relationship of the steel tube concrete composite structure, and cannot accurately obtain the load borne by each component after the internal structure is added. As a result, the stress of each component is still unclear, which seriously restricts the analysis of the stress behavior of the composite structure. Summary of the invention

[0005] The invention discloses a stress-strain constitutive testing structure to solve the above problems.

[0006] The present invention adopts the following scheme: The present application provides a stress-strain constitutive test structure for testing a steel tube concrete composite column with an inner filler stone filled in the center, comprising a first steel tube, a second steel tube, a third steel tube, a through-axis force sensor, and a circular force sensor; The upper end of the outer steel tube of the steel tube concrete composite column is provided with a placement cavity; the through-axis force sensor is placed in the placement cavity and is arranged on the concrete; the second steel tube is arranged on the through-axis force sensor; the circular force sensor is placed in the placement cavity and is arranged on the inner filling stone; the third steel tube is placed in the second steel tube and is arranged on the circular force sensor; the first steel tube is sleeved on the outer steel tube and placed on the outside of the placement cavity; the upper ends of the first steel tube, the second steel tube and the third steel tube are connected with an upper cover plate; A concrete pressure plate is arranged between the through-axis force sensor and the concrete; a stone pressure plate is arranged between the circular force sensor and the inner filling stone; the thickness of the first steel pipe, the second steel pipe and the third steel pipe is 2-3 times that of the outer steel pipe.

[0007] Furthermore, in the placement cavity of the steel tube concrete composite column, high-strength non-shrinkage grouting material is poured on the concrete and the inner filling stone.

[0008] Furthermore, a polytetrafluoroethylene membrane is provided between the outer steel tube and the concrete, and between the concrete and the inner filling stone in the steel tube concrete composite column.

[0009] Furthermore, the concrete pressing plate has the same shape and area as the upper end surface of the concrete.

[0010] Furthermore, the shape and area of ​​the stone pressing plate are the same as the upper end surface of the inner filling stone.

[0011] Furthermore, the inner diameter of the first steel pipe is matched with the outer diameter of the outer steel pipe.

[0012] Furthermore, a restraining ring plate is welded to the outer bottom of the first steel pipe.

[0013] By adopting the above technical solution, the present invention can achieve the following technical effects: The present application provides a variable constitutive test structure for testing a steel tube concrete composite column with a central inner filling stone. The structure ensures that each component in the steel tube concrete composite column is subjected to stress at the same time and has the same axial deformation through the connection of individual steel tubes. A through-axis force sensor is arranged on the concrete, and a circular force sensor is arranged on the inner filling stone. The load-displacement curves borne by the concrete and the inner filling stone in the steel tube concrete composite column can be directly and accurately measured respectively, thereby solving the deficiency that the traditional test method can only obtain the overall load-displacement relationship of the steel tube concrete composite structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a stress-strain constitutive test structure assembled to a steel tube concrete composite column structure according to an embodiment of the present invention; Figure 2 It is a schematic cross-sectional structure diagram of a stress-strain constitutive test structure assembled to a steel tube concrete composite column according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of a stress-strain constitutive test structure according to an embodiment of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the internal structure of a stress-strain constitutive test structure according to an embodiment of the present invention. Figure 2 ; Icon: Steel tube concrete composite column 1, stress-strain constitutive test structure 2, outer steel tube 11, concrete 12, inner filling stone 13, polytetrafluoroethylene membrane 14, high-strength non-shrinkage grouting material 15, lower pad 16, first steel tube 21, second steel tube 22, third steel tube 23, upper cover plate 24, constraint ring plate 212, through-axis force sensor 221, concrete pressure plate 222, circular force sensor 231, stone pressure plate 232, bolt 241. DETAILED DESCRIPTION

[0015] Example Combination Figures 1 to 4 As shown, this embodiment provides a stress-strain constitutive test structure 2, which is used to test a steel tube concrete composite column 1 filled with inner filling stone 13 in the center, including a first steel tube 21, a second steel tube 22, a third steel tube 23, a through-axis force sensor 221, and a circular force sensor 231; A placement cavity is provided at the upper end of the outer steel tube 11 of the steel tube concrete composite column 1; the through-axis force sensor 221 is placed in the placement cavity and is set on the concrete; the second steel tube 22 is set on the through-axis force sensor 221; the circular force sensor 231 is placed in the placement cavity and is set on the inner filling stone 13; the third steel tube 23 is placed in the second steel tube 22 and is set on the circular force sensor 231; the first steel tube 21 is sleeved on the outer steel tube 11 and placed on the outside of the placement cavity; the upper ends of the first steel tube 21, the second steel tube 22 and the third steel tube 23 are connected with an upper cover plate 24 by bolts 241.

[0016] By setting the connection of the steel pipe, it is ensured that the various components in the steel tube concrete composite column 1 are subjected to stress at the same time and have the same axial deformation. A through-axis force sensor 221 is set on the concrete, and a circular force sensor 231 is set on the internal filling stone 13. The load-displacement curves borne by the concrete 12 and the internal filling stone 13 in the steel tube concrete composite column 1 can be directly and accurately measured respectively, which solves the deficiency that the traditional test method can only obtain the overall load-displacement relationship of the steel tube concrete composite structure.

[0017] Specifically, in this embodiment, the steel tube concrete composite column 1 includes a square outer steel tube 11, an inner filling stone 13 arranged at the center of the outer steel tube 11, concrete 12 poured between the outer steel tube 11 and the inner filling stone 13, and a bottom plate 16 arranged at the bottom of the outer steel tube 11. A polytetrafluoroethylene film 14 is arranged between the outer steel tube 11 and the concrete 12, and between the concrete 12 and the inner filling stone 13 in the steel tube concrete composite column 1 to eliminate the influence of friction between them.

[0018] In the placement cavity of the steel tube concrete composite column 1, high-strength non-shrinkage grouting material is also poured on the concrete 12 and the internal filling stone 13. A concrete pressure plate 222 is arranged between the through-axis force sensor 221 and the concrete 12; the concrete pressure plate 222 has the same shape and area as the upper end surface of the concrete. An internal filling stone 13 pressure plate is arranged between the circular force sensor 231 and the internal filling stone 13, and the internal filling stone 13 pressure plate has the same shape and area as the upper end surface of the internal filling stone 13. The setting of the concrete pressure plate 222 can ensure that the upper load is evenly transferred to the interlayer concrete; the setting of the internal filling stone 13 pressure plate can ensure that the upper load can be evenly transferred to the internal filling stone 13.

[0019] In this embodiment, the first steel tube 21, the second steel tube 22 and the third steel tube 23 are all square steel tubes, and their thickness is 2-3 times that of the outer steel tube 11; to prevent compression buckling during the force process, while ensuring that the upper load can be effectively transmitted. The inner diameter of the first steel tube 21 is adapted to the outer diameter of the outer steel tube 11. A restraining ring plate 212 is welded to the outer bottom of the first steel tube 21.

[0020] Of course, in other embodiments, the outer steel tube 11 of the steel tube concrete composite column can also be in other shapes, such as a circle or other polygons; the shape of the first steel tube 21 is compatible with the outer steel tube 11. At the same time, the stress-strain constitutive test structure can also be applied to the constitutive test of various components of a concrete column with an internal steel tube. For example, the outer steel tube is square, circular or other polygons, and an internal steel tube is also arranged therein, and the internal steel tube can be square, circular or other polygons; concrete is poured between the outer steel tube and the internal steel tube; the stone is arranged in the internal steel tube, and the stone is processed into a shape compatible with the internal steel tube.

[0021] The specific implementation steps of the steel tube concrete composite column 1 and the stress-strain constitutive test structure 2 are described in detail below: First, the outer steel pipe 11, the first steel pipe 21, the second steel pipe 22 and the third steel pipe 23 are welded, and the bottom plate 16 is welded at the bottom of the outer steel pipe 11; Then, a layer of polytetrafluoroethylene film 14 is pasted on the inner surface of the outer steel pipe 11 and the side of the inner filling stone 13, and the inner filling stone 13 is placed at the center of the outer steel pipe 11. Then, concrete 12 is poured into the outer steel pipe 11, and a placement cavity and a 20mm grouting layer are reserved. After the concrete 12 is cured to a certain strength, a layer of 20mm thick high-strength non-shrinkage grouting material 15 is poured on the top surface of the inner filling concrete 12 and the inner filling stone 13, and the pre-made concrete pressure plate 222 and the inner filling stone 13 pressure plate are hoisted before the fluidity of the grouting material deteriorates to ensure that the concrete pressure plate 222 and the inner filling stone 13 pressure plate are fully compacted.

[0022] Finally, after the mortar hardens, the through-axis force sensor 221 and the circular force sensor 231 are placed on the concrete pressure plate 222 and the inner filling stone 13 pressure plate respectively, and then the first steel pipe 21 is sleeved on the outer steel pipe 11, the second steel pipe 22 is placed on the axial force sensor, and the third steel pipe is placed on the circular force sensor 231; finally, the square constraint ring plate 212 is welded on the bottom of the first steel pipe 21 to complete the production.

[0023] The loads borne by the concrete 12 and the internal filling stone 13 can be directly measured by the through-axis force sensor 221 and the circular force sensor 231, and the steel pipe load is obtained by subtracting the loads borne by the concrete and the internal filling stone 13 from the total load. Then, the load-displacement relationship of each component can be obtained, providing experimental data for the study of the compressive constitutive relationship of the outer steel pipe 11, concrete 12, and the internal filling stone 13.

[0024] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0025] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. A stress-strain constitutive test structure for testing a steel tube concrete composite column with inner filler stone in the center, characterized in that: It includes a first steel pipe, a second steel pipe, a third steel pipe, a through-axis force sensor, and a circular force sensor; The upper end of the outer steel tube of the steel tube concrete composite column is provided with a placement cavity; the through-axis force sensor is placed in the placement cavity and is arranged on the concrete; the second steel tube is arranged on the through-axis force sensor; the circular force sensor is placed in the placement cavity and is arranged on the inner filling stone; the third steel tube is placed in the second steel tube and is arranged on the circular force sensor; the first steel tube is sleeved on the outer steel tube and placed on the outside of the placement cavity; the upper ends of the first steel tube, the second steel tube and the third steel tube are connected with an upper cover plate by bolts; A concrete pressure plate is arranged between the through-axis force sensor and the concrete; a stone pressure plate is arranged between the circular force sensor and the inner filling stone; the thickness of the first steel pipe, the second steel pipe and the third steel pipe is 2-3 times that of the outer steel pipe.

2. The stress-strain constitutive test structure according to claim 1, characterized in that: In the placement cavity of the steel tube concrete composite column, high-strength non-shrinkage grouting material is poured on the concrete and the inner filling stone.

3. The stress-strain constitutive test structure according to claim 1, characterized in that: A polytetrafluoroethylene membrane is provided between the outer steel tube and the concrete in the steel tube concrete composite column, and between the concrete and the inner filling stone.

4. The stress-strain constitutive test structure according to claim 1, characterized in that: The concrete pressing plate has the same shape and area as the upper end surface of the concrete.

5. The stress-strain constitutive test structure according to claim 1, characterized in that: The shape and area of ​​the stone pressing plate are the same as the upper end surface of the inner filling stone.

6. The stress-strain constitutive test structure according to claim 1, characterized in that: The inner diameter of the first steel pipe matches the outer diameter of the outer steel pipe.

7. The stress-strain constitutive test structure according to claim 1, characterized in that: A restraining ring plate is welded to the outer bottom of the first steel pipe.

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