Fire-resistance performance test device for multi-type joint of building structure under coupling of fire load
By designing a fire resistance performance test device for building structures with multiple types of nodes under fire-load coupling, the problem of insufficient research on the fire resistance performance of multiple types of nodes in the existing technology has been solved. It realizes multi-directional load loading and thermo-mechanical coupling simulation, which significantly improves the comprehensiveness and applicability of the test.
Patent Information
- Application Number
- CN202522569976.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-12-03
AI Technical Summary
Existing technologies lack fire resistance testing devices for building structural nodes that can be compatible with multiple types of nodes and achieve multi-directional load coupling, resulting in insufficient research on the fire resistance performance of building structural nodes under fire load coupling.
A fire resistance performance test device for multiple types of nodes in building structures under fire-load coupling was designed, including a servo hydraulic loading system, a constraint support system, and a control and measurement system. It can simulate the thermo-mechanical coupling environment of multiple types of nodes, realize multi-directional load loading through servo hydraulic actuators, and simulate actual building nodes by using hinged or fixed connection methods.
It enables fire resistance performance testing of multiple types of nodes, improves the comprehensiveness and applicability of the tests, provides a scientific and efficient research platform, and significantly enhances the engineering applicability and scientific rigor of the test data.
Smart Images
Figure CN224933780U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of building fire resistance testing devices, and more specifically to a fire resistance performance testing device for multiple types of nodes in building structures under fire-load coupling effects. Background Technology
[0002] Currently, my country's national standard "Code for Fire Protection Design of Buildings" (GB 50016-2014 (2018 edition)) only specifies the combustion performance and fire resistance limit of corresponding components of buildings with different fire resistance ratings, such as walls, columns, beams, floor slabs, roof load-bearing components, evacuation staircases, and ceilings. However, it does not specify the fire resistance limit of building structural nodes, which are key components for the transmission and bearing of forces in building structures.
[0003] Structural joints refer to the points where building components or members connect to each other. Under the coupled effects of fire and load, widely used building materials such as steel, concrete, wood, and aluminum alloys undergo complex physicochemical changes, leading to deterioration of material properties and affecting the fire resistance of the building structure. Compared to components such as walls, slabs, beams, and columns during a fire, the failure of structural joints is a more dangerous situation. If a joint fails during a fire, it may cause the entire building structure to collapse progressively.
[0004] Compared to other building components in a fire, structural joints suffer a greater decline in mechanical performance due to the fire's impact. Taking a frame structure as an example: within the fire zone, slab members are primarily exposed to fire on the lower surface of the slab or the bottom surface of the slab in the upper space; frame beams are primarily exposed to fire on the bottom and sides of the beams in the upper space; and frame columns may be exposed to fire on one, two, three, or four sides. If there are partition walls, they are primarily exposed to fire on the side facing the fire zone. Since the joint area is affected by the combined heat transfer from the slabs, beams, columns, and walls, its mechanical performance may decline even more severely.
[0005] Due to limitations in testing equipment and imperfect testing methods, research on the fire resistance performance of building structural joints is relatively lacking compared to research on the fire resistance performance of building components. To clarify the stress mechanism of building structural joints during fire, it is necessary to experimentally verify the changes in the mechanical properties of these joints to determine the fire resistance time of the building structure, ensuring the safety of evacuation of personnel within the building and the safety of firefighters entering the building to conduct firefighting and rescue operations. Existing fire resistance testing equipment for structural components mainly targets single structural components such as slabs, beams, columns, walls, and ceilings, lacking equipment capable of conducting fire resistance tests on multiple types of building structural joints.
[0006] Therefore, how to develop a fire resistance performance testing device that can be compatible with multiple types of nodes and realize multi-directional load coupling has become an urgent technical problem to be solved. Utility Model Content
[0007] In view of this, the present invention provides a fire resistance performance testing device for multiple types of nodes in building structures under fire-load coupling effects, aiming to meet the fire resistance testing requirements of building structure nodes. To achieve the above objectives, the present invention adopts the following technical solution: A fire resistance performance testing device for multiple types of nodes in building structures under fire-load coupling effects, including Building structural nodes, which are classified according to structure as cross-shaped nodes, T-shaped nodes, K-shaped nodes or spherical nodes, and the web member connection section of the K-shaped node is provided with an angle adjustment mechanism; A fire-heating furnace, wherein the building structure node is located inside the fire-heating furnace, and the fire-heating furnace has several openings, allowing the ends of the building structure node to extend to the outside of the fire-heating furnace; A servo hydraulic loading system is used to load the loading end of a test specimen at a building structure node. The servo hydraulic loading system includes an upper column-end servo hydraulic actuator, left and right beam-end servo hydraulic actuators, an oblique servo hydraulic actuator, and a beam-span servo hydraulic actuator in the middle of the left and right beams. A constraint support system is used to constrain and fix the servo hydraulic loading system and building structure nodes; A control and measurement system, comprising a computer, a PLC, a distributed I / O module, and several thermocouples, wherein the thermocouples are distributed on the surface of the furnace body and building structural nodes, the thermocouples are electrically connected to the distributed I / O module, and the PLC is electrically connected to both the distributed I / O module and the computer.
[0008] Furthermore, the column-end servo hydraulic actuator is used to apply axial loads to the column ends of the cross-shaped node, the column ends of the T-shaped node, the chord of the K-shaped node, or the connecting rod of the spherical node. The beam-end servo hydraulic actuator is used to apply axial loads to the beam ends of cross-shaped and T-shaped nodes. The oblique servo hydraulic actuator is used to apply a unidirectional axial load to the web member of the K-shaped node or the connecting rod of the spherical node. The beam-span servo hydraulic actuator is used to apply unidirectional lateral loads or low-cycle reciprocating lateral loads to the middle of the beam at cross-shaped or T-shaped nodes.
[0009] Furthermore, the loading end of the specimen at the building structure node is hinged to the servo hydraulic loading system to avoid damage to the actuator, while the non-loading end of the specimen is either hinged or fixed according to the test requirements.
[0010] Furthermore, the heating area of the cross-shaped node is not less than 1 / 3 of the beam span for beams and not less than 1 / 3 of the total column height for columns; The heating area of the T-shaped node is no less than 1 / 3 of the beam span for beams and no less than 1 / 3 of the total column height for columns; The heating area of the K-shaped node has a web member that is not less than 1 / 3 of the total length of the web member, and a chord member that is not less than 1 / 3 of the total length of the chord member; The length of the heating area rod of the spherical node is not less than 1 / 3 of the total length of the connecting rod.
[0011] Furthermore, the fire heating furnace includes a furnace body, an insulation layer, and a natural gas combustion system. The furnace body is a cuboid structure with an opening. The insulation layer is made of composite fiber material and is arranged on the inner wall of the furnace body. The natural gas combustion system is used to uniformly heat the furnace body. The opening is configured as a unidirectional or opposing opening according to the node type to ensure that the end of the node specimen extends to the outside of the fire heating furnace for loading and constraint in the non-heated zone.
[0012] Furthermore, the furnace body is made of structural steel, and the insulation layer is made of aluminum silicate fiber insulation material.
[0013] Furthermore, the natural gas combustion system includes burners, a natural gas supply pipeline, a combustion-supporting fan, and an exhaust fan. The burners are short-flame burners, which are evenly arranged on the furnace wall and connected to the natural gas supply pipeline. The flame of the short-flame burners does not directly act on the test specimen. The combustion-supporting fan is arranged at the bottom of the furnace body, and the exhaust fan is arranged at the top of the furnace body.
[0014] The beneficial effects of this utility model are as follows: 1. This utility model, through a single testing device, meets the fire resistance performance testing requirements for various types of building structural nodes, such as cross-shaped nodes, T-shaped nodes, K-shaped nodes, and spherical nodes; it also meets the fire resistance performance testing requirements for building structural nodes made of multiple materials, such as concrete nodes, steel structure nodes, steel-concrete structure nodes, wood structure nodes, and aluminum alloy structure nodes; multi-directional load loading is achieved through vertical servo hydraulic actuators, horizontal servo hydraulic actuators, and oblique servo hydraulic actuators. Multi-directional constraint support is achieved through a constraint support system, including upper constraints, lower constraints, horizontal constraints, and oblique constraints; and by using a natural gas test furnace for heating, the thermal damage to building structural nodes caused by actual building fires can be more closely simulated.
[0015] 2. The structural nodes of this utility model are important force-transmitting and load-bearing components within buildings. The testing device of this utility model can perform fire resistance tests on both hinged and fixed node connections. Through the flexible configuration of hinged and fixed node connections, it achieves a realistic simulation of the diversity of actual building nodes, significantly improving the comprehensiveness and applicability of the test. This design not only enhances the comparability and completeness of the data but also improves economic efficiency through a modular constraint system and ensures the safety and reliability of the testing process, thus providing a scientific and efficient platform for the study of the fire resistance performance of building structures.
[0016] 3. This invention, through an integrated multi-dimensional loading system and adaptive constraint mechanism, achieves full-domain load simulation capabilities for irregularly shaped nodes such as cruciform, T-shaped, K-shaped, and spherical nodes. It not only supports the synergistic effect of axial loads at column ends and lateral constraints at beam ends, accurately reproducing the deformation behavior of cruciform / T-shaped nodes under thermo-mechanical coupling, but also, through an adjustable-angle oblique loading system, overcomes the geometric limitations of traditional equipment on K-shaped nodes, enabling the simulation of composite forces on chords and web members. Simultaneously, it is compatible with the axial load transfer path of spherical node spatial systems. This highly flexible load configuration system allows a single device to cover real fire conditions for multiple types of nodes, significantly improving the engineering applicability and scientific validity of the experimental data. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the fire resistance performance test of the cross-shaped building structure node in Embodiment 2 of this utility model; Figure 2 This is a schematic diagram of the fire resistance test of the T-shaped node in Embodiment 3 of this utility model; Figure 3 This is a schematic diagram of the fire resistance test of the K-shaped node in Embodiment 4 of this utility model; Figure 4 This is a schematic diagram of the fire resistance test of the spherical node in Embodiment 5 of this utility model; Figure 5 This is a front view of the heating furnace 3 of this utility model; Figure 6 This is a top view of the heating furnace 3 of this utility model.
[0018] In the diagram: 1-Building structural node, 201-Column end servo hydraulic actuator, 202-Beam end servo hydraulic actuator, 203-Inclined servo hydraulic actuator, 204-Beam span servo hydraulic actuator, 3-Heating furnace, 301-Furnace body, 302-Insulation layer, 303-Opening, 304-Natural gas combustion system, 401-Hinged constraint, 403-Vertical support, 404-Clamp. Detailed Implementation
[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0020] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "horizontal," "inner," "outer," and "one side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0021] Example 1: This embodiment discloses a fire resistance performance testing device for multiple types of joints in building structures under fire-load coupling effects, including: Building structural node 1 can be classified into cross-shaped node, T-shaped node, K-shaped node or spherical node according to the structure. According to the building material, building structural node 1 can be divided into reinforced concrete structural node, steel structural node, steel-concrete composite structural node, aluminum alloy structural node, wood structural node, etc. During the fire resistance test, the load needs to be applied simultaneously at the column end, beam end or beam span of building structural node 1. Fire heating furnace 3, building structure node 1 is set inside fire heating furnace 3, fire heating furnace 3 is provided with several openings 303, so that the end of building structure node 1 extends to the outside of fire heating furnace 3. A servo hydraulic loading system is used to load the loading end of the specimen at node 1 of the building structure. The servo hydraulic loading system includes a column-end servo hydraulic actuator 201 at the top, beam-end servo hydraulic actuators 202 on the left and right sides, an oblique servo hydraulic actuator 203, and a beam-span servo hydraulic actuator 204 in the middle of the left and right beams. The constraint support system is used to constrain and fix the servo hydraulic loading system and structural node 1. The constraint support system includes a hinge constraint 401, a fixed constraint, a vertical support 403, and a clamp 404. The hinge constraint 401 refers to a connection method between components that can transmit vertical and horizontal forces but not rotational torque. The fixed constraint refers to a connection method between components that can transmit both vertical and horizontal forces and rotational torque. The control and measurement system comprises a computer, a PLC, distributed I / O modules, and several thermocouples. Eight sets of "nickel-chromium-nickel-silicon (K-type)" thermocouples are distributed in furnace body 301, and at least eight sets of the same type of thermocouples are simultaneously arranged on the surface of building structure node 1, forming a multi-dimensional acquisition of the temperature gradient of the specimen. This dual-level temperature measurement strategy can accurately capture the dynamic heat exchange process between the node and the environment during fire simulation, providing complete data support for load-temperature coupling analysis. The thermocouples are electrically connected to the distributed I / O modules, and the PLC is electrically connected to both the distributed I / O modules and the computer. The distributed I / O modules centrally acquire and convert the thermocouple signals, which are then processed in real time by the PLC system. Finally, the computer completes data visualization and command issuance, forming a closed-loop control. This architecture not only ensures the synchronization and accuracy of temperature acquisition but also automatically adjusts the heating system according to preset test curves (such as the ISO834 standard fire curve), effectively eliminating the local errors of traditional single-point temperature measurement and significantly improving the scientific nature of fire resistance limit determination.
[0022] As a preferred embodiment of this utility model, the column-end servo hydraulic actuator 201 is used to apply axial load to the column end of the cross-shaped node, the column end of the T-shaped node, the chord of the K-shaped node, or the connecting rod of the spherical node; the beam-end servo hydraulic actuator 202 is used to apply axial load to the beam end of the cross-shaped node and the T-shaped node; the oblique servo hydraulic actuator 203 is used to apply unidirectional axial load to the web member of the K-shaped node or the connecting rod of the spherical node. The web member connecting section of the K-shaped node is provided with an angle adjustment mechanism, which includes a hinge base, an angle adjustment plate, and a locking bolt. It is connected to the hinge base through a hinge shaft. The angle adjustment plate can rotate around the hinge shaft in the horizontal plane, and its rotation range covers the typical angle between the web member and the horizontal axis (such as 30° to 60°). One end of the angle adjustment plate is fixed to the web member connection end by a pin, and the other end is locked by a locking bolt, so that the oblique servo hydraulic actuator 203 can rotate according to the angle between the web member and the horizontal axis; the beam span servo hydraulic actuator 204 is used to apply a unidirectional transverse load or a low-cycle reciprocating transverse load to the middle part of the beam at the cross-shaped node or T-shaped node.
[0023] In a preferred embodiment of this utility model, the loading end of the specimen and the servo hydraulic loading system are connected by a hinge to avoid damage to the actuator; the non-loading end of the specimen is connected by a hinge or a fixed connection according to the test requirements.
[0024] In a preferred embodiment of this utility model, the heating area of the cross-shaped node is not less than 1 / 3 of the beam span and not less than 1 / 3 of the total column height. The heating area of the T-shaped joint is no less than 1 / 3 of the beam span for beams and no less than 1 / 3 of the total column height for columns; For the heating area of the K-shaped node, the web members should be no less than 1 / 3 of the total length of the web members, and the chord members should be no less than 1 / 3 of the total length of the chord members. The length of the heating zone rod of the spherical node is not less than 1 / 3 of the total length of the connecting rod.
[0025] As a preferred embodiment of this utility model, the fire-heating furnace 3 includes a furnace body 301, an insulation layer 302, an opening 303, and a natural gas combustion system 304. The furnace body 301 is a cuboid structure with an opening 303, made of structural steel, such as Q235, Q355, Q390, Q420, or 304 stainless steel. The insulation layer 302 is made of composite fiber material, more specifically, aluminum silicate fiber insulation material, and is arranged on the inner wall of the furnace body 301. The natural gas combustion system 304 is used to uniformly heat the furnace body 301. The opening 303 is configured as a unidirectional or opposing opening 303 according to the node type to ensure that the end of the node specimen extends to the outside of the fire-heating furnace for loading and constraint in the non-heated area.
[0026] As a preferred embodiment of this utility model, the natural gas combustion system 304 includes burners, a natural gas supply pipeline, a combustion-supporting fan, and an exhaust fan. In this embodiment, the natural gas combustion system 304 uses natural gas as fuel and uses natural gas for heating, which can better simulate the thermal damage to the building structure node 1 caused by an actual building fire. The burners consist of 8 sets of short-flame burners, arranged on the four furnace walls, with 2 sets of short-flame burners arranged on each furnace wall for heating, ensuring that the burners uniformly heat the air inside the furnace, and requiring that the flames of the burners do not directly act on the surface of the test specimen. The short-flame burners have a manual / automatic seamless switching function, and the operator can operate the ignition of each burner in front of the furnace or on the instrument cabinet. The combustion-supporting fan is arranged at the bottom of the furnace body 301, and the exhaust fan is arranged at the top of the furnace body 301.
[0027] Example 2
[0028] like Figure 1 , Figure 5 , Figure 6As shown, this embodiment discloses a fire resistance performance testing device for multi-type nodes of building structures based on the fire-load coupling effect described in Embodiment 1, for the performance testing of cruciform node specimens. In this embodiment, the column-end servo hydraulic actuator 201 applies an axial load to the column end of the cruciform node, the beam-end servo hydraulic actuator 202 applies an axial load to the beam end of the cruciform node, and the beam-span servo hydraulic actuator 204 applies an upward load, a downward load, or an upward and downward reciprocating load to the middle of the beam of the cruciform node through the clamp 404. The constraints at the upper and lower column ends are hinged constraints 401, and the constraints at the left and right beam ends are hinged constraints 401. The vertical support 403 is used to provide support for the hinged constraints 401 at the left and right beam ends. The heating area of the cruciform node specimen is not less than 1 / 3 of the beam span for beams and not less than 1 / 3 of the total column height for columns. The width of the clamp 404 is the same as the beam width, and the length of the clamp 404 is not less than 20 cm.
[0029] Example 3: like Figure 2 , Figure 5 , Figure 6 As shown, this embodiment discloses a fire resistance performance testing device for multiple types of building structure nodes based on the fire-load coupling effect described in Embodiment 1, for the performance testing of T-shaped node specimens. In this embodiment, the column-end servo hydraulic actuator 201 applies an axial load to the column end of the T-shaped node, the beam-end servo hydraulic actuator 202 applies an axial load to the beam end of the T-shaped node, and the beam-span servo hydraulic actuator 204 applies an upward load, a downward load, or an upward and downward reciprocating load to the middle of the beam of the T-shaped node through the clamp 404. The constraints at the upper and lower column ends are hinged constraints 401, the constraint at the right beam end is a hinged constraint 401, and the vertical support 403 is used to provide support for the hinged constraint 401 at the right beam end. The heating area of the T-shaped node specimen is not less than 1 / 3 of the beam span for the beam and not less than 1 / 3 of the total column height for the column. The width of the clamp 404 is the same as the beam width, and the length of the clamp 404 is not less than 20 cm.
[0030] Example 4: like Figure 3 , Figure 5 , Figure 6 As shown, this embodiment discloses a fire resistance performance testing device for multiple types of building structure nodes based on the fire-load coupling effect described in Embodiment 1, for the performance testing of K-shaped node specimens. In this embodiment, the column-end servo hydraulic actuator 201 applies an axial load to the column end of the K-shaped node, and the oblique servo hydraulic actuator 203 applies a unidirectional axial load to the web members of the K-shaped node. The constraints on the upper and lower column ends are hinged constraints 401, and the constraints on the upper and lower web members are hinged constraints 401. The heated area of the web members of the K-shaped node specimen is not less than 1 / 3 of the web member length, and the chord members are not less than 1 / 3 of the total chord member length.
[0031] Example 5: like Figure 4 , Figure 5 , Figure 6 As shown, this embodiment discloses the performance testing of spherical node specimens using a fire-load coupling test device for multi-type nodes in building structures, based on the fire-load coupling effect described in Embodiment 1. For the spherical node specimen, in this embodiment, the column-end servo hydraulic actuator 201 applies an axial load to the connecting rod of the spherical node. The constraint of the upper and lower connecting rods can be a hinge constraint 401, and the length of the heating area rod of the spherical node specimen is not less than 1 / 3 of the total length of the upper and lower connecting rods.
[0032] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.
Claims
1. A fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effects, characterized in that, include: Building structural nodes, which are classified according to structure as cross-shaped nodes, T-shaped nodes, K-shaped nodes or spherical nodes, and the web member connection section of the K-shaped node is provided with an angle adjustment mechanism; A fire-heating furnace, wherein the building structure node is located inside the fire-heating furnace, and the fire-heating furnace has several openings, allowing the ends of the building structure node to extend to the outside of the fire-heating furnace; A servo hydraulic loading system is used to load the loading end of a test specimen at a building structure node. The servo hydraulic loading system includes an upper column-end servo hydraulic actuator, left and right beam-end servo hydraulic actuators, an oblique servo hydraulic actuator, and a beam-span servo hydraulic actuator in the middle of the left and right beams. A constraint support system is used to constrain and fix the servo hydraulic loading system and building structure nodes; A control and measurement system, comprising a computer, a PLC, a distributed I / O module, and several thermocouples, wherein the thermocouples are distributed on the surfaces of the fire-heating furnace and building structural nodes, the thermocouples are electrically connected to the distributed I / O module, and the PLC is electrically connected to both the distributed I / O module and the computer.
2. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 1, characterized in that, The column-end servo hydraulic actuator is used to apply axial loads to the column ends of cross-shaped nodes, T-shaped nodes, chords of K-shaped nodes, or connecting rods of spherical nodes. The beam-end servo hydraulic actuator is used to apply axial loads to the beam ends of cross-shaped and T-shaped nodes. The oblique servo hydraulic actuator is used to apply a unidirectional axial load to the web of the K-shaped node or the connecting rod of the spherical node. The beam-span servo hydraulic actuator is used to apply unidirectional lateral loads or low-cycle reciprocating lateral loads to the middle of the beam at cross-shaped or T-shaped nodes.
3. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 2, characterized in that, The loading end of the specimen at the building structure node is hinged to the servo hydraulic loading system to avoid damage to the actuator. The non-loading end of the specimen is either hinged or fixed, depending on the test requirements.
4. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 1, characterized in that, The heating area of the cross-shaped node is no less than 1 / 3 of the beam span for beams and no less than 1 / 3 of the total column height for columns; The heating area of the T-shaped node is no less than 1 / 3 of the beam span for beams and no less than 1 / 3 of the total column height for columns; The heating area of the K-shaped node has a web member that is not less than 1 / 3 of the total length of the web member, and a chord member that is not less than 1 / 3 of the total length of the chord member; The length of the heating area rod of the spherical node is not less than 1 / 3 of the total length of the connecting rod.
5. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 1, characterized in that, The fire heating furnace includes a furnace body, an insulation layer, and a natural gas combustion system. The furnace body is a cuboid structure with an opening. The insulation layer is made of composite fiber material and is arranged on the inner wall of the furnace body. The natural gas combustion system is used to uniformly heat the furnace body. The opening is configured as a unidirectional or opposing opening according to the node type to ensure that the end of the node specimen extends to the outside of the fire heating furnace for loading and constraint in the non-heated area.
6. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 5, characterized in that, The furnace body is made of structural steel, and the insulation layer is made of aluminum silicate fiber insulation material.
7. The fire resistance performance testing device for multiple types of nodes in a building structure under fire-load coupling effect as described in claim 5, characterized in that, The natural gas combustion system includes burners, a natural gas supply pipeline, a combustion-supporting fan, and an exhaust fan. The burners are short-flame burners, which are evenly arranged on the furnace wall and connected to the natural gas supply pipeline. The flame of the short-flame burners does not directly act on the test specimen. The combustion-supporting fan is arranged at the bottom of the furnace body, and the exhaust fan is arranged at the top of the furnace body.