Space structure reduced scale model fire test device

Abstract

The invention discloses a spatial structure reduced scale model fire test device, and relates to the technical field of building structure fire prevention. The device comprises a foundation, a lower enclosure structure, a space structure, an upper enclosure structure and a fire source device. The lower enclosure structure is installed on a foundation, and the space structure is erected on the upper portion of the lower enclosure structure and comprises rod pieces, cable systems and a supporting system which are connected through nodes. The upper enclosure structure is laid above the space structure; and the fire source device is arranged in the internal space above the foundation. According to the invention, a large-space building fire scene can be truly simulated, the mechanical response rule and temperature field distribution of the space structure at high temperature can be accurately reproduced, and the problem of lack of overall structure fire test means in the prior art is solved. The device is reasonable in structure, can be reused by replacing different space structure models, and provides a reliable test platform for fire resistance research and safety design of a large-span prestressed structure.

Description

Technical Field

[0001] This invention relates to the field of fire safety technology for building structures, specifically to an experimental device for studying the mechanical properties and response characteristics of large-span spatial structures under fire conditions, and more particularly to a fire test device for a scaled-down model of a spatial structure. Background Technology

[0002] Large-span spatial structures, such as stadiums, exhibition centers, and transportation hubs, are increasingly used in modern society. These buildings typically have high population density and high property value, making fire safety a particularly prominent issue. Spatial structures, as a rigid-flexible structural system, combine the advantages of rigid components and flexible cable systems, enabling large-span coverage and possessing superior load-bearing performance. However, due to the complexity of this type of structural system, including the interaction of various elements such as members, cables, and nodes, its mechanical behavior and failure mechanisms under high-temperature, non-uniform loads like fire are extremely complex, and systematic experimental data is currently lacking.

[0003] In existing technologies, research on the fire resistance performance of building structures mainly focuses on fire resistance tests of typical components or numerical simulation analysis. While independent fire resistance tests of typical components such as beams, columns, and slabs (e.g., CN106409117A and CN206259111U) can provide performance data at the component level, they are insufficient to reflect the collaborative action and internal force redistribution effects of the entire structural system under fire conditions. Numerical simulation methods, although less expensive, heavily rely on the setting of parameters such as constitutive models and boundary conditions, exhibiting significant uncertainty when simulating the coupling effect of fire and complex structures, and lacking sufficient experimental data verification and calibration. Furthermore, although scaled-down models exist in existing technologies, such as Chinese patent CN114923794A (a scaled-down similar model for explosion tests within a reticulated shell structure and its construction method), they focus on explosion loads, which differ from the thermal mechanism of fire. There is also a scaled-down model test device for tunnel fires (CN221200626U), but it is applied to linear tunnel scenarios and is not suitable for large-span spatial structures. In summary, existing technologies cannot conduct real fire tests on scaled-down models of spatial structures under controlled conditions, and cannot accurately reproduce the temperature field distribution and the resulting structural mechanical response in real fire scenarios, thus limiting the further improvement of fire-resistant design methods for this type of structure.

[0004] Therefore, there is an urgent need in this field for a general-purpose experimental device that can simulate large-space fire environments, support various scaled-down models of spatial structures, and obtain key response data under real fire conditions, in order to make up for the shortcomings of existing research methods and provide direct and reliable experimental support for theoretical research and engineering practice. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a test device that is structurally sound, reusable, and capable of accurately reflecting the structural response of large-span spatial structures under real fire conditions. This device can accurately and effectively reproduce the air temperature and mechanical fields of large-span spatial structures, compensating for the deficiencies of existing numerical simulation methods in the coupling study of fire simulation and structural response, thereby providing a theoretical basis for determining the structural stability of large-span spatial structures in the event of a fire.

[0006] To solve the above-mentioned technical problems, the technical solution proposed in this application is as follows: This invention provides a fire testing device for a scaled-down model of a spatial structure, comprising: foundation; The lower enclosure structure is installed on the upper part of the foundation; A spatial structure is erected on the upper part of the lower enclosure structure; the spatial structure includes hollow spherical nodes, reticulated shell members and struts connected to the hollow spherical nodes, ring cables connected to the struts, diagonal bars connected to the struts and ring cables, supports connected to the reticulated shell members and diagonal bars, and ring beams connected to the supports; The upper enclosure structure is laid on the upper part of the space structure; The ignition source device is installed on the foundation and located within the space enclosed by the lower enclosure structure and the spatial structure.

[0007] Furthermore, the upper enclosure structure is composed of aluminum silicate rock wool, with each piece of rock wool being fixedly connected by binding wire or high-temperature resistant tape.

[0008] Furthermore, the fire source device is a structure welded from multiple steel plates, and the size of the fire source device is adjustable to change the fire source power.

[0009] Furthermore, the lower enclosure structure includes an outer ring wall, an inner ring wall, window openings, door openings, lintels, and supporting columns; The outer ring wall is a brick wall, the inner ring wall is a fire-resistant brick wall, and the inner ring wall is connected to the outer ring wall; The window openings and the door openings are formed in the outer ring wall and the inner ring wall, respectively; The lintel is located above the window opening and the door opening; The supporting column is located between the outer ring wall and the inner ring wall. The lower part of the supporting column is connected to the embedded part of the foundation by bolts, and the upper part of the supporting column is connected to the ring beam by bolts.

[0010] Furthermore, the ring cable is a galvanized steel strand or a closed cable, and the diagonal bar is a high-strength steel tie rod; both the ring cable and the diagonal bar are connected to the support rod by pins.

[0011] Furthermore, the mesh shell rods, the struts, and the supports are all made of steel or seamless steel pipes.

[0012] Furthermore, the mesh shell members are connected to the hollow sphere nodes by welding; the upper part of the support rod is connected to the hollow sphere nodes by welding; the mesh shell members are connected to the support by welding; and the diagonal rod is connected to the support by a pin.

[0013] Furthermore, the dimensions of the window openings and door openings are determined based on the structure's ventilation factor, which is calculated using the following formula:

[0014]

[0015]

[0016] In the formula, Ventilation factor of the structure, in m 5 / 2 ; The total surface area of ​​the structural walls, in m². 2 This includes the area of ​​walls and ceilings, but excludes the area of ​​openings and floors; The total area of ​​openings in the structural wall, in m². 2 ; For the structural wall surface i The area of ​​each opening, in m² 2 ; The total number of openings in the structure; and The structural wall surface is the first i The height and width of each opening are in meters. The equivalent opening width of the structure is expressed in meters (m).

[0017] Furthermore, the foundation is made of reinforced concrete; the lintel is also made of reinforced concrete.

[0018] Furthermore, the device can be reused by replacing different types of spatial structures.

[0019] Compared with the prior art, the present invention achieves the following beneficial technical effects: The spatial structure scaled-down model fire testing device provided in this application can realistically simulate the fire environment of large-space buildings, accurately reproduce the mechanical response and temperature field distribution of the overall structure under high temperature, and effectively overcome the limitations of traditional nodal testing or numerical simulation. The device has a reasonable structural design and can be reused through replaceable spatial models. It provides a direct and reliable test platform for studying the failure mechanism and safety performance of large-span structures under fire, and is of great value for improving the fire resistance design and safety assurance level of such structures. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 An exploded view of a scaled-down model fire test device for a spatial structure provided in an embodiment of the present invention.

[0022] Figure 2 A schematic diagram of the fire source device for a spatial structure scaled model fire test device provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the enclosure structure of a scaled-down model fire test device for a spatial structure, provided as an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the ventilation opening of the enclosure structure of a scaled-down model fire test device for a spatial structure, provided as an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the supporting structure of the enclosure structure of a scaled-down model fire test device for spatial structures, provided as an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the spatial structure of a scaled-down model fire test device for spatial structures, provided as an embodiment of the present invention.

[0027] Explanation of markings in the diagram: 1. Upper enclosure structure; 2. Spatial structure; 3. Fire source device; 4. Lower enclosure structure; 5. Foundation; 20. Hollow spherical node; 21. Reticulated shell member; 22. Support rod; 23. Ring cable; 24. Diagonal member; 25. Support; 26. Ring beam; 40. Outer ring wall; 41. Inner ring wall; 42. Window opening; 43. Door opening; 44. Lintel; 45. Support column. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] See Figure 1 This diagram shows an overall exploded view of the scaled-down model fire test device of the present invention, including: an upper enclosure structure 1, a spatial structure 2, a lower enclosure structure 4, a fire source device 3, and a foundation 5. The spatial structure 2 is erected above the lower enclosure structure 4, and the upper enclosure structure 1 is laid and covered on top of the spatial structure 2. The fire source device 3 is placed on the foundation 5 and is located within the internal space defined by the lower enclosure structure 4 and the spatial structure 2. The foundation 5, as the cornerstone of the entire device, is located at the bottom.

[0030] Among them, the upper enclosure structure 1 is laid on the space structure 2; The spatial structure 2 includes a hollow spherical node 20, a reticulated shell member 21 connected to the hollow spherical node 20, a strut 22 connected to the hollow spherical node, a ring cable 23 connected to the strut 22, an inclined bar 24 connected to the strut 22 and the ring cable 23, a support 25 connected to the reticulated shell member 21 and the inclined bar 24, and a supporting ring beam 26 connected to the support. The ignition source device 3 is placed on the foundation 5 and used as a ignition source.

[0031] The lower enclosure structure 4 includes an outer ring wall 40 made of ordinary bricks, an inner ring wall 41 made of firebricks connected to the outer ring wall 40, window openings 42 in the outer ring wall 40 and the inner ring wall 41, door openings 43 in the outer ring wall 40 and the inner ring wall 41, lintels 44 erected above the window openings 42 and the door openings 43, and support columns 45 connected to the support ring beam 26.

[0032] Foundation 5, with the lower enclosure structure 4 and fire source device 3 installed on the upper part.

[0033] like Figure 2 As shown, Figure 2 This is a schematic diagram of the ignition source device for a scaled-down model fire test apparatus of a spatial structure provided in an embodiment of the present invention. The ignition source device 3 is welded from multiple steel plates. It contains flammable liquid fuel, which serves as the ignition source for the test apparatus. Different ignition power can be achieved by changing the different dimensions of the ignition source device 3.

[0034] like Figure 3 As shown, Figure 3This is a schematic diagram of the enclosure structure of a scaled-down model fire test device for a spatial structure, provided as an embodiment of the present invention. The enclosure structure includes an upper enclosure structure 1, a lower enclosure structure 4, and a foundation 5.

[0035] The upper enclosure structure 1 is composed of aluminum silicate rock wool. The rock wool pieces are connected by binding wire and high-temperature resistant tape. The upper enclosure structure 1 is laid on top of the space structure 2, mainly to prevent flue gas from escaping from the top of the test device, and also serves as thermal insulation.

[0036] The lower enclosure structure 4 is installed at the lower part of the space structure 2, serving both to support the space structure 2 and to provide thermal insulation for the lower part of the device. The lower enclosure structure 4 is installed on the upper part of the foundation 5.

[0037] The foundation 5 provides the load-bearing base for the entire test device. The foundation 5 is made of reinforced concrete and is cast in place on site. The upper part is used to install the lower enclosure structure 4 and to place the ignition source device 3.

[0038] like Figure 4 As shown, Figure 4 This is a schematic diagram of the ventilation opening of the enclosure structure of a scaled-down model fire test device for a spatial structure, provided in an embodiment of the present invention. It includes an outer wall 40 constructed of ordinary bricks, an inner wall 41 constructed of fire-resistant bricks connected to the outer wall 40, window openings 42 in the outer wall 40 and the inner wall 41, door openings 43 in the outer wall 40 and the inner wall 41, and lintels 44 erected above the window openings 42 and the door openings 43.

[0039] The outer ring wall 40 is made of ordinary bricks and is installed on the outermost side of the lower enclosure structure 4.

[0040] The inner ring wall 41 is constructed of firebricks and is connected to the outer ring wall 40 by mortar. It is installed on the innermost side of the lower enclosure structure 4.

[0041] Window opening 42 is located both inside the outer ring wall 40 and the inner ring wall 41. The size of the window opening is determined based on the ventilation coefficient of the structure.

[0042] Doorway 43 is located both inside the outer wall 40 and the inner wall 41. The size of the doorway is determined based on the ventilation coefficient of the structure.

[0043] The method for determining the above ventilation coefficient is as follows:

[0044]

[0045]

[0046] In the formula, Ventilation factor of the structure (m) 5 / 2); The total surface area of ​​the structural wall (m²) 2 This includes the area of ​​walls and ceilings, but excludes the area of ​​openings and floors; The total area of ​​openings in the structural wall (m²) 2 ); For the structural wall surface i Area of ​​each opening (m²) 2 ); The total number of openings in the structure; and The structural wall surface is the first i Height and width of each opening (in meters); The equivalent opening width of the structure is (m).

[0047] Lintel 44, installed above window openings 42 and door openings 43, is used to strengthen the door and window openings. The lintel 44 can be made of reinforced concrete. Its dimensions must conform to the relevant masonry structure specifications.

[0048] like Figure 5 As shown, Figure 5 This is a schematic diagram of the supporting structure of the enclosure structure of a scaled-down model fire test device for a spatial structure, provided in an embodiment of the present invention. The supporting column 45 is embedded between the outer ring wall 40 and the inner ring wall 41, and its lower part is connected to the pre-embedded parts reserved in the foundation 5 by bolts. Its upper part is connected to the ring beam 26 by bolts.

[0049] like Figure 6 As shown, Figure 6 This is a schematic diagram of the spatial structure of a scaled-down model fire test device for a spatial structure provided in an embodiment of the present invention. The spatial structure 2 includes a hollow spherical node 20, a mesh shell member 21 connected to the hollow spherical node 20, a support rod 22 connected to the hollow spherical node, a ring cable 23 connected to the support rod 22, an inclined rod 24 connected to the support rod 22 and the ring cable 23, a support 25 connected to the mesh shell member 21 and the inclined rod 24, and a supporting ring beam 26 connected to the support.

[0050] Hollow spherical node 20 is made of steel.

[0051] The reticulated shell member 21 is made of seamless steel pipe and is connected to the hollow sphere node 20 by welding.

[0052] The strut 22 is made of seamless steel pipe, and its upper part is connected to the hollow spherical node 20 by welding. Its lower part is connected to the ring cable 23 and the diagonal bar 24 by a pin.

[0053] The ring cable 23 is made of galvanized steel strand or closed cable. The ring cable 23 is installed at the lower part of the support rod 22 and connected by a pin.

[0054] The diagonal brace 24 is made of high-strength steel tie rod. The diagonal brace 24 is connected to the lower part of the support rod 22 by a pin. The outermost diagonal brace 24 is also connected to the support rod 25 by a pin.

[0055] Support 25 is made of steel. The grid shell member 21 is connected to support 25 by welding. The diagonal member 24 is connected to support 25 by a pin connection.

[0056] The ring beam 26 is made of steel. Its upper part is connected to the support 25 by bolts, and its lower part is connected to the column 45 by bolts.

[0057] Those skilled in the art will understand that spatial structure 2 includes various types of spatial structures, and this test apparatus is equally applicable.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for a scale model fire test of a spatial structure, characterized in that, The device comprises: a foundation (5); a lower enclosure (4) installed on the upper part of the foundation (5); a space structure (2) erected on the upper part of the lower enclosure (4); the space structure (2) comprises hollow spherical nodes (20), net shell rods (21) connected with the hollow spherical nodes (20) and struts (22), ring cables (23) connected with the struts (22), diagonal rods (24) connected with the struts (22) and the ring cables (23), supports (25) connected with the net shell rods (21) and the diagonal rods (24), and ring beams (26) connected with the supports (25); an upper enclosure (1) laid on the upper part of the space structure (2); a fire source device (3) arranged on the upper part of the foundation (5) and located in the space enclosed by the lower enclosure (4) and the space structure (2).

2. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The upper enclosure (1) is composed of aluminum silicate rock wool, and each piece of rock wool is fixedly connected by binding wires or high-temperature-resistant adhesive tapes.

3. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The fire source device (3) is a structure welded by multiple steel plates, and the size of the fire source device (3) can be adjusted to change the power of the fire source.

4. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The lower enclosure (4) comprises an outer ring wall (40), an inner ring wall (41), window openings (42), door openings (43), lintels (44) and support columns (45). The outer ring wall (40) is a brick wall, the inner ring wall (41) is a refractory brick wall, and the inner ring wall (41) is connected with the outer ring wall (40). The window openings (42) and the door openings (43) are arranged on the outer ring wall (40) and the inner ring wall (41). The lintels (44) are arranged on the upper parts of the window openings (42) and the door openings (43). The support columns (45) are arranged between the outer ring wall (40) and the inner ring wall (41), the lower parts of the support columns (45) are connected with the embedded parts of the foundation (5) by bolts, and the upper parts of the support columns (45) are connected with the ring beams (26) by bolts.

5. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The ring cables (23) are galvanized steel wires or closed cables, and the diagonal rods (24) are high-strength steel rods; the ring cables (23) and the diagonal rods (24) are connected with the struts (22) by pins.

6. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The net shell rods (21), the struts (22) and the supports (25) are made of steel or seamless steel pipes.

7. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The net shell rods (21) are connected with the hollow spherical nodes (20) by welding, the upper parts of the struts (22) are connected with the hollow spherical nodes (20) by welding, the net shell rods (21) are connected with the supports (25) by welding, and the diagonal rods (24) are connected with the supports (25) by pins.

8. The reduced scale model fire test apparatus for a space structure according to claim 4, wherein The sizes of the window openings (42) and the door openings (43) are determined according to a ventilation factor of the structure, and the ventilation factor is calculated by the following formula: wherein is the ventilation factor of the structure, in m 5 / 2 ; is the total surface area of the structure wall, in m 2 , including the area of walls and ceilings, and excluding the area of openings and floors; is the total area of openings of the structure wall, in m 2 ; is the area of the nth opening of the structure wall, in m i ; 2 ; is the total number of openings of the structure; and are the height and width, respectively, of the nth opening of the structure wall, in m; i ; is the equivalent opening width of the structure, in m.

9. The reduced scale model fire test apparatus for a space structure according to claim 1, wherein The foundation (5) is made of reinforced concrete, and the lintels (44) are made of reinforced concrete.

10. The reduced scale model fire testing apparatus for a space structure according to any one of claims 1 to 9, characterized in that, The device can be reused by replacing different types of space structures (2).

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