Steel structure connecting joint capable of releasing fire temperature deformation

Abstract

The invention discloses a steel structure connecting joint capable of releasing fire temperature deformation, which comprises a first steel structure component, a second steel structure component, a plurality of friction type high-strength bolts and a connecting plate, and is characterized in that the connecting plate is provided with a long elliptical bolt hole, and the long elliptical bolt hole comprises a bolt hole near end and a bolt hole far end; a plurality of friction type high-strength bolts are in friction type connection with the connecting plate, the first steel structure component and the second steel structure component, so that the first steel structure component and the second steel structure component are spliced together, and then the steel structure connecting joint is formed; under the fire working condition, the first steel structural component and the second steel structural component deform due to temperature, and the friction type high-strength bolt slides from the near end of the bolt hole to the far end of the bolt hole, so that the temperature deformation of the first steel structural component and the second steel structural component under the fire working condition is released; the steel structure connecting joint is easy to install and environmentally friendly, and can still meet the structural fireproof safety requirement under the designed fire working condition.

Description

Technical Field

[0001] The present application relates to the field of steel structure fire protection, and in particular to a steel structure connection node capable of releasing fire temperature deformation. Background Art

[0002] Steel structure itself has significant advantages such as light weight, high strength, convenient installation, short cycle, high material recovery rate, etc., but it has the disadvantage of poor fire resistance. Therefore, according to the current domestic design specifications, it is necessary to verify the fire protection of steel structure, that is, the fire condition, and require that within the specified time, the steel structure cannot lose its basic use function.

[0003] For steel structural members that are mainly subjected to bending, according to the current specifications, there is no need to consider the temperature strain under fire conditions, only the strength and stiffness reduction under fire conditions need to be considered, and the current fireproof materials can basically meet the relevant requirements. However, for steel structural members that are mainly subjected to axial forces, such as steel supports, the current specifications require that the temperature strain under fire conditions must be considered. But in fact, for steel structural members that are mainly subjected to axial forces, huge temperature strains will be generated under fire conditions, far exceeding the allowable strength value of the steel structure itself. In fact, for axially stressed members such as steel supports with a long fireproofing time, it is impossible to pass the fire condition verification required by the current specifications.

[0004] According to the current specifications, for steel structural members such as steel supports that are mainly subjected to axial forces, the temperature strain under fire conditions should be considered. According to the fire protection level 2 estimate, the fire resistance hours of steel supports are 2.5 hours for the same column. For steel structures that have taken protective measures, the support temperature is generally over 400 degrees after 2.5 hours. Assuming that both ends are fully constrained, at 400°C, an 8m long steel support will produce an axial temperature deformation of about 45mm. The temperature stress alone can be estimated to be more than 1100MPa, which is far more than the yield strength of current steel (high-strength steel for structures is generally below 390MPa).

[0005] Of course, the two ends of the actual components cannot generally achieve full constraints, and some axial deformation may be reduced by coordinating with the deformation of the column. However, the ground support of the bottom floor or the support connected to the concrete structure often has similar strong constraint restrictions, and the temperature stress generated is very huge. In actual projects, it is often encountered that no matter what fire prevention measures are taken, the fire condition verification cannot be passed. In other words, in fact, this type of steel structure cannot guarantee basic use functions under fire conditions due to the existence of axial deformation.

[0006] In the prior art, fire protection is carried out by using solutions such as supporting external concrete or using reinforced concrete structures, which actually abandons the advantages of steel structures such as easy installation and environmental protection.

[0007] Therefore, there is an urgent need in this field to develop a steel structure connection node that can release fire temperature strain. The steel structure connection node, which is mainly subjected to axial force, is easy to install and environmentally friendly, and can still meet the structural fire safety requirements under the design fire conditions. Summary of the invention

[0008] The purpose of the present application is to provide a steel structure connection node that can release fire temperature deformation. The steel structure connection node, which is mainly subjected to axial force, is easy to install and environmentally friendly, and can still meet the structural fire safety requirements under the design fire conditions.

[0009] The present application provides a steel structure connection node capable of releasing fire temperature deformation, comprising:

[0010] A first steel structure member, a second steel structure member, a plurality of friction-type high-strength bolts and a connecting plate, wherein the connecting plate is provided with an oblong bolt hole, wherein the oblong bolt hole comprises a proximal end of the bolt hole and a distal end of the bolt hole, and the plurality of friction-type high-strength bolts are frictionally connected with the connecting plate and the first steel structure member and the second steel structure member, so that the first steel structure member and the second steel structure member are spliced ​​together to form a steel structure connection node;

[0011] Wherein, when the first steel structure member and the second steel structure member are spliced ​​together, the friction-type high-strength bolt is arranged at the proximal end of the bolt hole of the oblong bolt hole on the connecting plate. Under fire conditions, the first steel structure member and the second steel structure member are subjected to temperature deformation, and the friction-type high-strength bolt slides from the proximal end of the bolt hole toward the distal end of the bolt hole, thereby releasing the temperature deformation of the first steel structure member and the second steel structure member under fire conditions.

[0012] In another preferred example, the friction type high-strength bolts are arranged along the length direction of the second steel structure member.

[0013] In another preferred example, the first steel structure member and the second steel structure member have the same structure.

[0014] In another preferred example, the temperature deformation includes temperature stress and temperature strain.

[0015] In another preferred embodiment, the connecting plate is a steel plate.

[0016] In another preferred embodiment, the number of the friction type high-strength bolts is 2, 4, or 8.

[0017] In another preferred example, an additional temperature weakening pad is further included, which is arranged above or below the connecting plate, and the friction type high-strength bolt passes through the additional temperature weakening pad. Under fire conditions, the additional temperature weakening pad softens, thereby reducing the friction force of the friction type high-strength bolt, thereby causing the friction type high-strength bolt to slide from the proximal end of the bolt hole to the distal end of the bolt hole.

[0018] In another preferred embodiment, the additional temperature weakening cushion layer is made of a metal material that is sensitive to temperature, can be softened at high temperatures and has a certain strength.

[0019] In another preferred example, it also includes a pad with a temperature weakening layer, which is arranged above or below the connecting plate, and the friction type high-strength bolt passes through the pad. Under fire conditions, the temperature weakening layer on the pad softens, thereby reducing the friction force of the friction type high-strength bolt, and then causing the friction type high-strength bolt to slide from the proximal end of the bolt hole toward the distal end of the bolt hole.

[0020] In another preferred example, the pad provided with the temperature weakening layer is arranged between the friction type high-strength bolt and the connecting plate, or the pad provided with the temperature weakening layer is between the first steel structure member and / or the second steel structure member and the connecting plate.

[0021] In another preferred embodiment, the temperature weakening layer is made of tin metal or tin alloy, or a metal material that is sensitive to temperature, can be softened at high temperature and has a certain strength, and the material of the pad is steel.

[0022] In another preferred embodiment, the backing plate is an alloy support that can soften before reaching the design temperature.

[0023] In another preferred example, when the designed maximum temperature is reached, the temperature weakening layer of the pad is completely softened, the friction-type high-strength bolt slides to the far end of the bolt hole, and the connection between the friction-type high-strength bolt and the connecting plate and the first steel structure member and the second steel structure member is transformed from a friction-type connection to a pressure-bearing connection.

[0024] In another preferred embodiment, at the designed maximum temperature, the first steel structure member and the second steel structure member still meet the structural fire safety requirements.

[0025] In another preferred example, when the designed maximum temperature is reached, the additional temperature weakening cushion layer is completely softened, the friction type high-strength bolt slides to the far end of the bolt hole, and the connection between the friction type high-strength bolt and the connecting plate and the first steel structure member and the second steel structure member is transformed from a friction type connection to a pressure-bearing connection.

[0026] In another preferred embodiment, the designed maximum temperature is obtained based on the number of fire protection hours under the fire protection level of the steel structural member.

[0027] In another preferred embodiment, the designed maximum temperature is related to the burning material of the fire, the actual fire retardant coating of the steel structure, its external shape, and the number of fire-exposed surfaces.

[0028] In another preferred example, assuming that the first steel structure component is a constrained component and the second steel structure component is an unconstrained component, the size of the major axis of the oblong bolt holes of the plurality of friction-type high-strength bolts is related to the length of the second steel structure component, the linear expansion coefficient of the steel, and the design maximum temperature.

[0029] In another preferred example, the first steel structure member and the second steel structure member have the same structure, and the first steel structure member and the second steel structure member include but are not limited to: H-shaped steel, box-shaped steel, T-shaped steel, and L-shaped steel.

[0030] In another preferred example, when the first steel structure member and the second steel structure member are H-shaped steels, the plurality of friction-type high-strength bolts and connecting plates are arranged on the flanges of the H-shaped steels.

[0031] In another preferred example, the first steel structure member and the second steel structure member are mainly subjected to axial force in their normal working state.

[0032] In another preferred embodiment, the steel structure connection node is a support node subjected to axial force or a beam-column node subjected to both axial force and bending moment.

[0033] In another preferred embodiment, the connection plate is surface treated according to the requirements of the friction type high-strength bolt and the friction coefficient, so as to ensure the friction coefficient of the contact surface between the friction type high-strength bolt and the connection plate.

[0034] In another preferred example, the backing plate is surface treated according to the requirements of the friction type high-strength bolt and the friction coefficient, so as to ensure the friction coefficient of the contact surface between the friction type high-strength bolt and the backing plate.

[0035] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. It should be understood that the drawings described below are only some implementation examples of the present invention, and ordinary technicians in this field can also obtain other implementation examples based on these drawings without paying creative work.

[0037] Figure 1 is a structural schematic diagram of a steel structure connection node according to a first embodiment of the present application, wherein friction-type high-strength bolts are arranged on a first steel structure member and a second steel structure member;

[0038] Figure 2 is a schematic diagram of an oblong threaded hole on a connecting plate according to a first embodiment of the present application, wherein the length of the major axis of the oblong hole is shown;

[0039] Figure 3 is a structural schematic diagram of a steel structure connection node according to a second embodiment of the present application, wherein a friction-type high-strength bolt is arranged on a second steel structure member;

[0040] Figure 4 is a schematic diagram of an oblong threaded hole on a connecting plate according to a first embodiment of the present application, wherein the length of the major axis of the oblong hole is shown;

[0041] Figure 5 A schematic diagram showing the sliding of a friction-type high-strength bolt to release temperature deformation under fire conditions is shown, wherein when the maximum design temperature is not reached, the temperature weakening layer of the pad begins to soften and the bolt begins to slide toward the far end;

[0042] Figure 6 The schematic diagram shows that when the maximum temperature of the design fire condition is reached, the friction type high-strength bolt slides to the far end (limit position) of the bolt hole, wherein the temperature weakened layer of the pad is completely softened, the bolt slides to the limit position, and the screw begins to be sheared;

[0043] Figure 7 A schematic diagram showing the application of the steel structure connection point capable of releasing fire temperature deformation to a support node subjected to axial force;

[0044] Figure 8 A schematic diagram showing the application of the steel structure connection point capable of releasing fire temperature deformation to a beam-column node subjected to both axial force and bending moment.

[0045] In the accompanying drawings, the following are marked:

[0046] 1-First steel structure component

[0047] 2- Second steel structure member

[0048] 3-Friction type high strength bolts

[0049] 4-Connection plate

[0050] 41-Oval bolt hole

[0051] 411- Bolt hole near end

[0052] 412-bolt hole far end

[0053] 5- Pad with temperature weakening layer DETAILED DESCRIPTION

[0054] Through extensive and in-depth research, the inventors have developed for the first time a steel structure connection node that can release fire temperature deformation. This steel structure connection node, which is mainly subjected to axial force, is provided with an oblong bolt hole so that when a fire occurs, the friction-type high-strength bolts slide and reduce the temperature strain of the steel structure components caused by high temperature, thereby meeting safety requirements; in addition, an additional temperature weakening pad is provided around the friction-type high-strength bolts. When a fire occurs, the additional temperature weakening pad softens, thereby reducing the friction force of the friction-type high-strength bolts, and then causing the friction-type high-strength bolts to slide toward the far end of the bolt hole, thereby reducing the temperature strain of the steel structure components caused by high temperature.

[0055] the term

[0056] Steel support: It can be frame support or horizontal support, etc. The stress state is mainly axial deformation;

[0057] Fire calculation of steel structure: Fire calculation and fire design of steel structure are carried out according to the ultimate limit state of fire resistance bearing capacity of the structure;

[0058] Fire temperature strain: Under fire conditions, the material will expand due to thermal expansion and contraction, and the temperature will gradually rise over time. After the temperature rises, due to the constraints at both ends, additional compressive strain will be generated, and its effect is similar to forced deformation;

[0059] High-strength bolt pressure-bearing connection: a connection method that relies on the shear resistance of the screw and the pressure of the screw and the hole wall to transmit shear force;

[0060] High-strength bolt friction connection: a connection method that relies on the tightening of high-strength bolts to generate friction between the connected parts to transmit shear force;

[0061] As used herein, "bolt hole proximal end" refers to the end proximal to the connection between the first steel structural member and the second steel structural member;

[0062] As used herein, "distal end of the bolt hole" refers to an end away from the connection between the first steel structural member and the second steel structural member;

[0063] As used herein, "design maximum temperature" and "design fire condition maximum temperature" are used interchangeably;

[0064] As used herein, "connector plate" and "gusset plate" are used interchangeably;

[0065] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the application documents of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements. Expressions such as multiple, multiple, and multiple include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0066] In the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0067] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0068] Main advantages of this application:

[0069] (a) The steel structure connection node capable of releasing fire temperature strain of the present application can meet the fire protection design specifications, and the steel structure connection point can meet the safety requirements under fire conditions;

[0070] (b) The steel structure connection node capable of releasing fire temperature strain of the present application releases fire temperature deformation by setting an oblong bolt hole, and the size of the bolt hole can be calculated and adjusted according to the maximum allowable temperature (maximum temperature of the design fire condition);

[0071] (c) Add a high temperature weakening layer (temperature weakening layer) or a thin alloy layer that is sensitive to high temperature on the pad. The temperature weakening layer can be made of metal materials such as metal tin or tin alloy that are sensitive to temperature and have a certain strength; it is similar to the fuse effect of the bolt. The friction strength reduction temperature (the temperature at which the temperature weakening layer softens and reduces the friction strength) should be lower than but as close to the design maximum temperature as possible, so that the bolt can work normally under normal working conditions, but the friction of the bolt can be reduced in time under the fire temperature (design maximum temperature), and the bolt is allowed to have a certain amount of displacement but still maintain a certain friction;

[0072] (d) The steel structure connection node capable of releasing fire temperature strain of the present application adds a temperature weakening layer to the friction type high-strength bolt, so that at high temperatures, due to the softening of the temperature weakening layer, the friction force of the friction type high-strength bolt can be reduced in time to cause sliding, thereby releasing the temperature deformation of the fire.

[0073] Design fire condition maximum temperature / design maximum temperature

[0074] According to the current design specifications, steel structures are required to meet safety requirements within a specified number of hours after a fire occurs. For example, the fire protection hours required for steel structure supports with a fire protection grade of one is 3 hours. Combining the burning materials of the simulated fire, the actual fire retardant coating of the steel structure, the external shape, and the number of fire-affected surfaces, the temperature rise curve of the steel structure can be obtained. The temperature of the steel structure with the horizontal coordinate t (hours) in the temperature rise curve is found to be the design fire condition of the steel structure. The temperature of the design fire condition is the maximum temperature of the design fire condition or the design maximum temperature. If it can still meet the structural safety requirements at this temperature, it proves that its fire resistance time exceeds t (hours). Steel structure connection nodes that can release fire temperature deformation

[0075] See also Figure 1-Figure 4 The present application provides a steel structure connection node capable of releasing fire temperature deformation, comprising: a first steel structure member 1, a second steel structure member 2, a plurality of friction-type high-strength bolts 3 and a connection plate 4, wherein an oblong bolt hole 41 is provided on the connection plate 4, wherein the oblong bolt hole 41 comprises a bolt hole proximal end 411 and a bolt hole distal end 412, wherein the plurality of friction-type high-strength bolts 3 are frictionally connected with the connection plate 4 and the first steel structure member 1 and the second steel structure member 2, so that the first steel structure member 1 and the second steel structure member 2 are spliced ​​together to form a steel structure connection node;

[0076] Among them, when the first steel structure member 1 and the second steel structure member 2 are spliced ​​together, the friction type high strength bolt 3 is arranged at the bolt hole proximal end 411 of the oblong bolt hole 41 on the connecting plate 4. Under fire conditions, the first steel structure member 1 and the second steel structure member 2 are subjected to temperature deformation, and the friction type high strength bolt 3 slides from the bolt hole proximal end 411 toward the bolt hole distal end 412, thereby releasing the temperature deformation of the first steel structure member 1 and the second steel structure member 2 under fire conditions. In one embodiment, the friction type high strength bolt 3 is arranged along the member length direction of the second steel structure member 2.

[0077] In one embodiment, it also includes: a pad 5 provided with a temperature weakening layer, the pad 5 is arranged above or below the connecting plate 4 (that is, the pad 5 provided with a temperature weakening layer is arranged between the friction type high-strength bolt 3 and the connecting plate 4 or the pad 5 provided with a temperature weakening layer is between the first steel structure member 1 and / or the second steel structure member 2 and the connecting plate 4), and the friction type high-strength bolt 3 passes through the pad 5, under fire conditions, the temperature weakening layer on the pad 5 softens, thereby reducing the friction of the friction type high-strength bolt 3, and then causing the friction type high-strength bolt 3 to slide toward the far end 412 of the bolt hole, wherein the temperature weakening layer is made of tin metal or tin alloy, or a metal material that is sensitive to temperature and has a certain strength, and the material of the pad 5 is steel. In another embodiment, the pad 5 is an alloy support that can soften before reaching the design temperature. In other words, the pad is designed to have the same material as the temperature weakening layer. It should be noted that the material of the different temperature weakening layers is selected according to different design maximum temperatures. The material selection of the temperature weakening layer should follow the principle that the starting softening temperature is lower than the designed maximum temperature, but in order to achieve a good effect, preferably, the material temperature of the temperature weakening layer should be as close to the designed maximum temperature as possible. More preferably, the material temperature of the temperature weakening layer can be the same as the designed maximum temperature.

[0078] In another embodiment, an additional temperature weakening pad 5 is further included, and the additional temperature weakening pad 5 is arranged above or below the connecting plate 4, and the friction type high strength bolt 3 passes through the additional temperature weakening pad 5. Under fire conditions, the additional temperature weakening pad 5 softens, thereby reducing the friction force of the friction type high strength bolt 3, and then the friction type high strength bolt 3 slides toward the far end 412 of the bolt hole. The additional temperature weakening pad 5 is made of a metal material that is sensitive to temperature, can soften at high temperature, and has a certain strength.

[0079] In one embodiment, the backing plate 5 with the temperature weakened layer can be replaced by an additional thin backing layer made entirely of a material that can soften at high temperatures.

[0080] In another embodiment, the number of the friction type high-strength bolts 3 is 2, 4, or 8.

[0081] Principle of the Invention

[0082] See also Figure 1-Figure 4 , the connection plate 4 and the pad 5 should be surface treated according to the requirements of the friction type and friction factor of the high-strength bolt to ensure the friction coefficient of the contact surface. The screw of the high-strength bolt should meet the relevant requirements of the pressure-bearing high-strength bolt and the friction-type high-strength bolt. During construction, the tightening force should be applied according to the friction-type high-strength bolt. The bolt should be installed on one side of the long elliptical hole (the near end 411 of the bolt hole) to reserve space for temperature expansion.

[0083] Assuming that the first steel structure member 1 is a constrained member and the second steel structure member 2 is an unconstrained member, under fire conditions, the temperature deformation of the second steel structure member 2 is dominant relative to the temperature deformation of the first steel structure member. The calculated expansion deformation of the second steel structure member 2 is △L. According to Figure 1-Figure 2 As shown, friction-type high-strength bolts are friction-installed on the first steel structure member 1 to fix the first steel structure member 1, and friction-type high-strength bolts are friction-installed on the second steel structure member 2 to fasten the first steel structure member 1 and the second steel structure member 2. At this time, the reserved space (long axis size) of the bolt hole on the connecting plate 4 (node ​​plate) is △L / 2 (see Figure 2 ), wherein the friction-type high-strength bolts of the first steel structure member 1 and the second steel structure member 2 are frictionally mounted on the bolt hole proximal ends 411 of their respective oblong bolt holes 41 on the connecting plate 4;

[0084] See also Figure 3 and Figure 4 If only the second steel structure member 2 is equipped with friction-type high-strength bolts to fasten the first steel structure member 1 and the second steel structure member 2, the reserved space (long axis dimension) of the bolt hole on the connecting plate 4 (node ​​plate) is △L( Figure 4 ).

[0085] Among them, △L can be taken as △t*12α*10 -6 *L / 2, where △t=tt 0 , t is the design maximum temperature, t 0 is the ambient temperature, α is the linear expansion coefficient of the steel structure α=12*10 -6 , L is the length of the second steel structure member.

[0086] The pad shall be provided with an additional layer that can be softened at the design temperature or all the bearings shall be made of alloys that can be softened at the design temperature, and its strength shall be determined by the tightening force requirements of friction-type high-strength bolts. The first steel structure member / the second steel structure member can be of various common cross-sections, such as H-type (the steel structure member in the attached figure is shown as H-type), box-type, T-type, and L-type. The node plate is a steel plate.

[0087] See also Figure 2 , Figure 5 and Figure 6 Taking the frame node as an example, under normal circumstances, the installation requirements and force mode are the same as those of ordinary friction type high-strength bolts. The friction type high-strength bolt 3 is frictionally installed at the bolt hole proximal end 411 ( Figure 2 ), according to the requirements of the current seismic code, the node bearing capacity is higher than the bearing capacity of the component. However, under fire conditions, the temperature weakening layer in the pad with a temperature weakening layer will cause the bolts to loosen slightly when the temperature does not reach the design maximum temperature, and its friction will be slightly weakened, and it will slide slightly along the direction of the long elliptical bolt hole to release the temperature deformation. Under fire conditions but before the design maximum temperature is reached, its working mode is still similar to that of ordinary friction-type high-strength bolts, but the bearing capacity will decrease. At this time, the node bearing capacity is lower than the component bearing capacity, but higher than the component internal force; at this time, the static friction of the friction-type connection of the bolt will be reduced to sliding friction, which becomes a protective measure for the component without damage (see Figure 5 ). When the fire condition reaches the highest design temperature, the axial deformation of the bolt reaches the limit (the friction-type high-strength bolt 3 slides from the proximal end 411 of the bolt hole to the distal end 412 of the bolt hole), and its bearing mode changes from friction type to pressure type, and the screw rod resists shear, and its bearing capacity rises again. At this time, the node bearing capacity should be close to the component bearing capacity, and the internal force of the node and the component is also close to the bearing capacity (see Figure 6 ).

[0088] In fact, under fire conditions, the bearing capacity of high-strength bolts will decrease due to high temperature, and some slip may occur. However, since normal bolt holes are not long elliptical holes, the components do not have the ability to release temperature stress, and the internal forces of the components are all borne by the screws. At this time, the node screws will be sheared. If the high-temperature weakening layer is not used, due to the requirements of seismic resistance, the node bearing capacity must be higher than the component bearing capacity. Before the connecting bolts have time to slide, the components have been damaged due to the backlog of temperature strain. Therefore, for nodes with node bearing capacity higher than the component bearing capacity, such as vertical support nodes, a temperature weakening layer must be set, otherwise the node slip cannot yield before the component; for nodes whose node bearing capacity is lower than the component bearing capacity during design, a temperature weakening layer may not be set, but a long elliptical hole must be set to ensure that the node slides and does not cause shear extrusion of the screw before the design temperature is reached.

[0089] In addition, for nodes such as non-frame nodes whose inherent node bearing capacity is lower than the component bearing capacity, the pad with the temperature weakening layer can be cancelled and only elliptical bolt holes can be provided.

[0090] To make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that these are only some examples that the present invention may take for the reader, but are not intended to limit the scope of the present invention.

[0091] Example

[0092] See also Figure 1 The present application provides a steel structure connection node capable of releasing deformation caused by fire temperature. The core components are a pad 5 provided with a high temperature weakening layer, 8 friction-type high-strength bolts 3, a connection plate 4 with long elliptical bolt holes, and structural members (a first steel structure member 1 and a second steel structure member 2). The temperature weakening layer can be in direct contact with the steel structure member / connection plate 4, or can be placed between the friction-type high-strength bolts 3 and the connection plate 4. Its position can be freely adjusted as long as the bolt tightening force is reduced as required. Among them, the connection plate 4 and the pad 5 are steel plates, and the temperature weakening layer is made of tin metal or tin alloy, or a metal material that is sensitive to temperature, can soften at high temperatures, and has a certain strength.

[0093] In this embodiment, the first steel structure member 1 and the second steel structure member 2 have the same structure and are both H-shaped steel plates. The first steel structure member 1 is a constrained member, and the second steel structure member 2 is an unconstrained member. An oblong bolt hole 41 is provided on the connecting plate 4. The oblong bolt hole 41 includes a proximal end 411 of the bolt hole and a distal end 412 of the bolt hole. A plurality of friction-type high-strength bolts 3 are friction-connected with the connecting plate 4 and the first steel structure member 1 and the second steel structure member 2, so that the first steel structure member 1 and the second steel structure member 2 are spliced ​​together to form a steel structure connection node; wherein the friction-type high-strength bolts 3 are arranged on the flanges of the H-shaped steel of the first steel structure member 1 and the second steel structure member 2. The friction-type high-strength bolts 3 are arranged along the length direction of the second steel structure member 2. The length direction of the connecting plate 4 is parallel to the length direction of the second steel structure member 2. The length direction of the connecting plate 4 refers to the direction of the plane of the connecting plate 4 in contact with the first steel structure member 1 and the second steel structure member 2 at the same time.

[0094] When the first steel structure member 1 and the second steel structure member 2 are spliced ​​together, the friction type high strength bolt 3 is installed at the bolt hole proximal end 411 (see Figure 2 ), under fire conditions (or when a fire occurs), the first steel structure member 1 and the second steel structure member 2 are deformed by temperature, and the temperature weakening layer on the backing plate 5 softens, thereby reducing the friction force of the friction type high-strength bolt 3, and then causing the friction type high-strength bolt 3 to slide from the proximal end 411 of the bolt hole toward the distal end 412 of the bolt hole (see Figure 5), thereby releasing the temperature deformation of the first steel structure member 1 and the second steel structure member 2 under fire conditions, and the temperature deformation may include temperature stress and temperature strain.

[0095] When the design maximum temperature is reached, the temperature weakened layer of the backing plate 5 is completely softened, the friction type high-strength bolt 3 slides to the far end 412 of the bolt hole (the limit position), the screw begins to be sheared, and the connection between the friction type high-strength bolt 3 and the connecting plate 4 and the first steel structure member 1 and the second steel structure member 2 is transformed from a friction type connection to a pressure type connection (see Figure 6 ), so that at the design maximum temperature, the first steel structure member 1 and the second steel structure member 2 still meet the structural fire safety requirements.

[0096] It should be noted that the design maximum temperature is based on the number of fire protection hours under the fire protection level of the steel structure components. The design maximum temperature is related to the burning material of the fire, the actual fire retardant coating of the steel structure, the external shape, and the number of fire-affected surfaces (see the description of the design maximum temperature above).

[0097] In addition, the steel structure connection node of this embodiment can be applied to the support node subjected to axial force (see Figure 7 ) or beam-column joints subjected to both axial force and bending moment ( Figure 8 ).

[0098] Among them, Figure 7 In the figure, the first steel structure member 1 is a steel column (constrained member), the second steel structure member 2 is a supporting member (unconstrained member), the second steel structure member 2 mainly bears axial force, and a friction type high-strength bolt 3 is arranged on the second steel structure member. The first steel structure member 1 and the second steel structure member 2 are spliced ​​together by a connecting plate 4 and the friction type high-strength bolt 3, so as to release the temperature deformation generated by the second steel structure member 2 under fire conditions (when a fire occurs), wherein a pad (not shown) with a temperature weakening layer is arranged above or below the connecting plate 4, which is used to reduce the friction force of the friction type high-strength bolt 3 under fire conditions, as described above.

[0099] Among them, Figure 8 In the figure, the first steel structure member 1 is a steel column (constrained member), the second steel structure member 2 is a frame beam (unconstrained member), the second steel structure member 2 mainly bears axial force and bending moment, friction type high-strength bolts 3 are arranged on the web and flange of the second steel structure member 2, the first steel structure member 1 and the second steel structure member 2 are spliced ​​together by connecting plates 4 and friction type high-strength bolts 3, so as to release the temperature deformation generated by the second steel structure member 2 under fire conditions (when a fire occurs), wherein a pad (not shown) with a temperature weakening layer is arranged above or below the connecting plate 4, which is used to reduce the friction force of the friction type high-strength bolts 3 under fire conditions, as described above.

[0100] A large number of technical features are recorded in the specification of this application, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded.

[0101] All documents mentioned in this application are considered to be included in the disclosure of this application as a whole, so that they can be used as the basis for modification when necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art can make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A steel structure connection node capable of releasing fire temperature deformation, characterized in that: include: A first steel structure component (1), a second steel structure component (2), a plurality of friction-type high-strength bolts (3) and a connecting plate (4), wherein the connecting plate (4) is provided with an oblong bolt hole (41), wherein the oblong bolt hole (41) comprises a bolt hole proximal end (411) and a bolt hole distal end (412), and wherein the plurality of friction-type high-strength bolts (3) are frictionally connected with the connecting plate (4) and the first steel structure component (1) and the second steel structure component (2), so that the first steel structure component (1) and the second steel structure component (2) are spliced ​​together, thereby forming a steel structure connection node; Wherein, when the first steel structure component (1) and the second steel structure component (2) are spliced ​​together, the friction type high-strength bolt (3) is arranged at the proximal end (411) of the bolt hole of the oblong bolt hole (41) on the connecting plate (4); under fire conditions, the first steel structure component (1) and the second steel structure component (2) are subjected to temperature deformation, and the friction type high-strength bolt (3) slides from the proximal end (411) of the bolt hole toward the distal end (412) of the bolt hole, thereby releasing the temperature deformation of the first steel structure component (1) and the second steel structure component (2) under fire conditions.

2. The steel structure connection node according to claim 1, characterized in that: It also includes an additional temperature weakening pad (5), which is arranged above or below the connecting plate (4), and the friction type high strength bolt (3) passes through the additional temperature weakening pad (5). Under fire conditions, the additional temperature weakening pad (5) softens, thereby reducing the friction force of the friction type high strength bolt (3), thereby causing the friction type high strength bolt (3) to slide from the proximal end (411) of the bolt hole toward the distal end (412) of the bolt hole.

3. The steel structure connection node according to claim 1, characterized in that: It also includes a pad (5) provided with a temperature weakening layer, the pad (5) being arranged above or below the connecting plate (4), and the friction type high-strength bolt (3) passing through the pad (5), and under fire conditions, the temperature weakening layer on the pad (5) softens, thereby reducing the friction force of the friction type high-strength bolt (3), thereby causing the friction type high-strength bolt (3) to slide from the proximal end (411) of the bolt hole toward the distal end (412) of the bolt hole.

4. The steel structure connection node according to claim 3, characterized in that: The temperature weakening layer is made of tin metal or tin alloy, or a metal material that is sensitive to temperature, can be softened at high temperature and has a certain strength, and the material of the pad (5) is steel.

5. The steel structure connection node according to claim 4, characterized in that: When the designed maximum temperature is reached, the temperature weakening layer of the pad (5) is completely softened, the friction-type high-strength bolt (3) slides to the far end (412) of the bolt hole, and the connection between the friction-type high-strength bolt (3) and the connecting plate (4) and the first steel structure member (1) and the second steel structure member (2) is transformed from a friction-type connection to a pressure-bearing connection.

6. The steel structure connection node according to claim 5, characterized in that: The design maximum temperature is obtained based on the number of fire protection hours under the fire protection level of the steel structural member.

7. The steel structure connection node according to claim 1, characterized in that: Assuming that the first steel structure component (1) is a constrained component and the second steel structure component (2) is an unconstrained component, the size of the major axis of the oblong bolt holes (41) of the plurality of friction-type high-strength bolts (3) is related to the length of the second steel structure component (2), the linear expansion coefficient of the steel, and the design maximum temperature.

8. The steel structure connection node according to claim 1, characterized in that: The first steel structure component (1) and the second steel structure component (2) have the same structure, and the first steel structure component (1) and the second steel structure component (2) include but are not limited to: H-shaped steel, box-shaped steel, T-shaped steel, and L-shaped steel.

9. The steel structure connection node according to claim 8, characterized in that: When the first steel structure component (1) and the second steel structure component (2) are H-shaped steels, the plurality of friction-type high-strength bolts (3) and the connecting plates (4) are arranged on the flanges of the H-shaped steels.

10. The steel structure connection node according to any one of claims 1 to 9, characterized in that: The first steel structure component (1) and the second steel structure component (2) are mainly subjected to axial force in their normal working state.

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