Movable steel structure special-shaped cast steel joint

Abstract

The invention belongs to the technical field of cast steel joints, and discloses a movable steel structure special-shaped cast steel joint which comprises a first supporting pipe, a second supporting pipe and a third supporting pipe are sequentially arranged on the outer side of the middle of the first supporting pipe, and a fourth supporting pipe is arranged between the second supporting pipe and the third supporting pipe; the two ends of the first supporting pipe, the top end of the second supporting pipe, the top end of the third supporting pipe and the top end of the fourth supporting pipe are each provided with a guide limiting assembly. Two sets of connecting lugs are further arranged on the outer side of the middle of the first supporting pipe, and one end of each connecting lug is movably connected with a connecting pipe. By arranging the guiding and limiting assemblies, the connecting lugs and the connecting lugs, the guiding and limiting effects can be achieved in the connecting process with a steel pipe, connection with an inclined pipe can be achieved conveniently, meanwhile, the inclined pipe can achieve the small-range swinging effect, and then a certain anti-seismic effect can be achieved; and the connection requirement between the steel pipes is better met.

Description

Technical Field

[0001] The invention relates to the technical field of cast steel nodes, and in particular to a movable special-shaped cast steel node for a steel structure. Background Art

[0002] With the continuous improvement of my country's steel structure design technology and the increasingly novel structural forms, steel castings are used in building steel structures with complex node structures and concentrated forces due to their advantages of high bearing capacity, high rigidity and good seismic performance. Moreover, steel castings are also flexible in design, and have the greatest freedom of choice in shape and size. In particular, special-shaped complex shapes and hollow parts can be manufactured by the unique process of core steel castings, and finished products can be quickly produced according to drawings. Steel castings improve the overall structural strength according to the needs of the project, and coupled with weight-reducing design and shorter delivery time, they greatly save production time, improve construction efficiency and shorten construction time.

[0003] In the field of modern steel structure construction, especially in large-scale construction projects with complex design requirements such as sports centers, subway stations, theaters and museums, cast steel nodes, as key components for connecting steel pipes, play a vital role. With the rapid development of steel structure technology, its application in buildings with large spans and complex shapes is becoming more and more extensive. For special buildings such as large museums, designers often need to introduce inclined columns to achieve more diverse architectural shapes. However, welding beams or steel pipes directly on inclined columns is not only technically difficult, but also has insufficient support and is easy to break, making it difficult to meet the diverse needs of architectural design.

[0004] Therefore, how to provide a movable special-shaped cast steel node for steel structure is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiment of the present invention provides a movable special-shaped cast steel node of a steel structure to solve the above-mentioned technical problems in the prior art.

[0006] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0007] To this end, the specific technical solution adopted by the present invention is as follows:

[0008] A movable steel structure special-shaped cast steel node comprises a first supporting tube, a second supporting tube and a third supporting tube are sequentially arranged on the outer side of the middle part of the first supporting tube, and a fourth supporting tube is arranged between the second supporting tube and the third supporting tube; both ends of the first supporting tube, the top end of the second supporting tube, the top end of the third supporting tube and the top end of the fourth supporting tube are all provided with guide limit assemblies; two groups of connecting ears are also arranged on the outer side of the middle part of the first supporting tube, and the connecting ears are located on the back side of the middle part of the first supporting tube, and the ends of the connecting ears away from the first supporting tube are movably connected with matching connecting tubes, and the connecting tubes and the connecting ears can present a swing angle of 3°-5°.

[0009] In one embodiment, in order to facilitate the connection between steel pipes, the diameters of the first support pipe, the second support pipe and the fourth support pipe are gradually reduced, and the diameters of the second support pipe and the third support pipe are equal. The second support pipe, the third support pipe and the fourth support pipe are all perpendicular to the first support pipe. The second support pipe and the third support pipe are arranged at an obtuse angle, and the fourth support pipe is located in the middle of the second support pipe and the third support pipe. A plurality of fixing rings are arranged inside the first support pipe, the second support pipe, the third support pipe and the fourth support pipe.

[0010] In one embodiment, in order to play a guiding and limiting effect in the process of connecting with the steel pipe, the guiding and limiting assembly includes a guiding ring installed at both ends of the first support tube, the top of the second support tube, the top of the third support tube and the top of the fourth support tube, and the outer side of the guiding ring is evenly provided with a plurality of installation grooves, and the inside of the installation groove is provided with a matching limiting strip; both ends of the limiting strip close to the inner wall of the installation groove are provided with limiting blocks, and the side of the limiting strip close to the inner wall of the installation groove is evenly provided with a plurality of rectangular grooves, and the inside of the rectangular groove is provided with a spring, and the side of the limiting strip away from the installation groove is evenly provided with anti-slip grooves. The diameter of the guiding ring on the first support tube, the second support tube and the fourth support tube gradually decreases, and the diameter of the guiding ring on the second support tube is equal to that of the guiding ring on the third support tube. The diameter of the guiding ring on the first support tube, the second support tube and the fourth support tube is smaller than its own diameter. The two groups of connecting ears are arranged at an obtuse angle, the connecting ear is arranged at an obtuse angle with the first support tube, and the connecting ear is inclined from the first support tube toward the direction away from the first support tube.

[0011] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0012] 1) By providing a guide limit assembly, a connecting ear and a connecting column, not only can the guide limit assembly play a guiding and limiting role in the process of connecting with the steel pipe, but also the connecting column can facilitate the connection with the inclined pipe. At the same time, due to the existence of the connecting ear and the connecting column, the inclined pipe can achieve a small range of swing effect, and thus can play a certain anti-seismic effect, better meeting the connection requirements between steel pipes.

[0013] 2) By providing a guide and limit assembly, not only can the guide ring play a guiding effect on the connection of the steel pipe, but also the spring and the limit strip can play a certain limiting effect on the connected steel pipe, thereby better meeting the connection requirements between the steel pipes.

[0014] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] Figure 1 is a structural schematic diagram of a movable special-shaped cast steel node of a steel structure according to an exemplary embodiment;

[0017] Figure 2 It is a structural schematic diagram of a guide and limit assembly in a movable special-shaped cast steel node of a steel structure according to an exemplary embodiment;

[0018] Figure 3 yes Figure 2 A magnified view of the local structure at point A in the middle;

[0019] Figure 4 The diagram is a schematic diagram of the installation of a spring in a movable special-shaped cast steel node of a steel structure according to an exemplary embodiment.

[0020] In the figure:

[0021] 1. First support tube; 2. Second support tube; 3. Third support tube; 4. Fourth support tube; 5. Guide and limit assembly; 501. Guide ring; 502. Mounting groove; 503. Limit strip; 504. Limit block; 505. Rectangular groove; 506. Spring; 507. Anti-slip pattern; 6. Connecting ear; 7. Fixing ring; 8. Connecting tube. DETAILED DESCRIPTION

[0022] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0023] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0025] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0026] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0027] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0028] Figure 1-Figure 4 An embodiment of a movable steel structure special-shaped cast steel node of the present invention is shown.

[0029] In this optional embodiment, the movable steel structure special-shaped cast steel node includes a first support tube 1, and a second support tube 2 and a third support tube 3 are sequentially arranged on the outer side of the middle part of the first support tube 1, and a fourth support tube 4 is arranged between the second support tube 2 and the third support tube 3; both ends of the first support tube 1, the top of the second support tube 2, the top of the third support tube 3 and the top of the fourth support tube 4 are all provided with guide limit assemblies 5; two groups of connecting ears 6 are also arranged on the outer side of the middle part of the first support tube 1, and the connecting ears 6 are located on the back side of the middle part of the first support tube 1, and the ends of the connecting ears 6 away from the first support tube 1 are movably connected with a connecting tube 8 matching therewith. In specific applications, the connecting tube 8 is connected to the inclined column by a number of fixing bolts or welding, and the connected inclined tube can present a swing angle of 3°-5° through the action of the connecting ears 6 and the connecting tube 8.

[0030] Specifically, the material of the connecting ear of the steel casting is Q345B, the allowable tensile stress is [σ]L=295MPa, the allowable contact stress is [σ]c=400MPa, the allowable shear stress is [τ]L=170MPa, and the dynamic load comprehensive coefficient is K=2. Combined with the weight of the maximum steel casting, the size of the connecting ear of the steel casting is selected as follows: the diameter of the top semicircle R1=80mm, the inner diameter of the pin hole R2=25mm, the overall height L1=200mm, the overall length L2=160mm, the thickness T=20mm, the number of connecting ears n=2, the horizontal angle of the rigging α=60°, the horizontal projection angle β=10°, and F=78000N. The stress of the connecting ear is checked as shown below:

[0031] Vertical load F v =K*F / n=39000N=39KN;

[0032] Cable direction load F L =F v / sinα = 45 kN;

[0033] Horizontal load F H =F L *cosα=22.5KN;

[0034] Maximum stress in the sling direction σL=F L / (2*(R1-R2)*T)=21MPa<[σ]L=295MPa, meeting the requirements;

[0035] Maximum shear stress in the sling direction τL=F L / [(R1-R2)*T]=42MPa<[τ]L=170MPa, meeting the requirements;

[0036] Contact stress σc=F L / (2*R2*T)=45MPa<[σ]c=400MPa, meeting the requirements;

[0037] Vertical tensile stress of the lifting lug σv=F v / (2*R1*T)=13MPa<300MPa, meets the requirements;

[0038] It can be concluded that the bearing capacity of the connecting ear meets the requirements. The connecting ear is welded according to the first-level full penetration weld. After welding, ultrasonic flaw detection is carried out. Only after the test is qualified can the next step be carried out.

[0039] With the aid of the above-mentioned technical scheme of the present invention, by providing the guide limit assembly 5, the connecting ear 6 and the connecting tube 8, not only can the guide limit assembly 5 play a guiding and limiting role in the process of connecting with the steel pipe, but also the connecting tube 8 can facilitate the connection with the inclined tube. At the same time, due to the presence of the connecting ear 6 and the connecting tube 8, the inclined tube can achieve a small range of swing effect, thereby having a certain anti-seismic effect, and better meeting the connection requirements between steel pipes.

[0040] In this optional embodiment, the diameters of the first support tube 1, the second support tube 2 and the fourth support tube 4 gradually decrease, and the diameters of the second support tube 2 and the third support tube 3 are equal. The second support tube 2, the third support tube 3 and the fourth support tube 4 are all perpendicular to the first support tube 1. The second support tube 2 and the third support tube 3 are arranged at an obtuse angle, and the fourth support tube 4 is located in the middle of the second support tube 2 and the third support tube 3. A plurality of fixing rings 7 are arranged inside the first support tube 1, the second support tube 2, the third support tube 3 and the fourth support tube 4, so as to facilitate the connection between the steel tubes.

[0041] In this optional embodiment, the guide and limit assembly 5 includes a guide ring 501 installed at both ends of the first support tube 1, the top of the second support tube 2, the top of the third support tube 3 and the top of the fourth support tube 4. The outer side of the guide ring 501 is evenly provided with a plurality of installation grooves 502, and the interior of the installation grooves 502 is provided with a limit strip 503 that matches therewith; both ends of the limit strip 503 close to the inner wall of the installation groove 502 are provided with a limit block 504, and the side of the limit strip 503 close to the inner wall of the installation groove 502 is evenly provided with a plurality of rectangular grooves 505, and the interior of the rectangular grooves 505 is provided with a spring 506, and the side of the limit strip 503 away from the installation groove 502 is evenly provided with an anti-slip pattern 507. The diameters of the guide rings 501 on the first support tube 1, the second support tube 2 and the fourth support tube 4 gradually decrease, and the diameters of the guide ring 501 on the second support tube 2 and the guide ring 501 on the third support tube 3 are equal. The diameters of the guide rings 501 on the first support tube 1, the second support tube 2 and the fourth support tube 4 are all smaller than their own diameters. The two groups of connecting ears 6 are arranged at an obtuse angle, the connecting ears 6 are arranged at an obtuse angle with the first support tube 1, and the connecting ears 6 are arranged obliquely from the first support tube 1 toward the direction away from the first support tube 1. By providing the guide limit assembly 5, not only can the connection of the steel pipe be guided under the action of the guide ring 501, but also a certain limit effect can be played on the connected steel pipe under the action of the spring 506 and the limit strip 503, thereby better meeting the connection requirements between the steel pipes.

[0042] In specific application, the key points of operation of the special-shaped cast steel node of the present invention during processing and production include:

[0043] 1. The production process of steel castings mainly includes two parts: the front-end production process and the back-end process. The front-end production process includes molding and core making, baking and coating, box assembly (mold matching), smelting and pouring. The back-end process mainly includes box unpacking, sand removal, sand cleaning, gas cutting, shot blasting, carbon planing (digging defects), heat treatment, finishing and rust prevention treatment.

[0044] 2. The steel castings are processed and produced in the foundry according to the above-mentioned production process, and the raw materials of the steel castings are tested with an ultrasonic flaw detector. After the flaw detectors have completed the inspection and the supervisor has confirmed that the steel castings are qualified, the finished steel castings can be sent to the steel structure manufacturer for the next production process.

[0045] 3. Steel castings and spherical plain bearings are stamped using a special process at the steel structure manufacturer. The spherical plain bearings are installed on the steel castings according to the design requirements of the drawings, and their swing angle is guaranteed to be 3°-5° to meet the actual installation requirements of the inclined columns on site.

[0046] 4. Special-shaped spherical plain bearing castings should be accompanied by a quality inspection certificate when leaving the factory. After the materials arrive at the site, they should be subjected to size and shape inspection, internal structure inspection, wall thickness inspection, and ultrasonic (magnetic particle) flaw detection of the castings to ensure that the castings are fully qualified and free of defects before they can be used.

[0047] 5. To ensure the safety, applicability and economic rationality of the nodes, the finite element software ANSYS is used to analyze the bearing capacity of the cast steel nodes. According to the overall analysis results, the cast steel nodes with the largest force under the most unfavorable combination are selected for analysis. The column foot node and the column head node have the same cross-section, and the node with the largest force is selected for verification; for the other nodes with similar shapes and cross-sectional specifications, the node with the largest force is selected for verification. The cast steel nodes connected to the steel columns are analyzed according to the relevant requirements of seismic performance-based design. Since the structure is symmetrically arranged, the nodes on the left half of the overall model are selected for analysis.

[0048] The selection of analysis models and material properties are in accordance with the original design description of cast steel nodes, the Technical Specification for Application of Cast Steel Nodes (CECS235:2008) and the Technical Specification for Cast Steel Structures (JGJ / T 395-2017). The material of the cast steel is G20Mn5N, and the heat treatment state is normalizing. The elastic modulus of the material Es = 206000MPa, the Poisson's ratio μ = 0.3, and its material properties are shown in Table 1 and Table 2. The bilinear model is used for the cast steel material properties during calculation. The elastic modulus of cast steel Es = 206000MPa, the yield strength is 300MPa, and after entering the elastic-plastic stage, the bilinear isotropic kinematic hardening constitutive relationship is adopted, and the strengthening modulus is 5% of the initial modulus, which is 10000MPa.

[0049] Table 1 Chemical composition of cast steel (%)

[0050] Brand C Si Mn P S Ni G20Mn5N 0.17～0.23 ≤0.60 1.0～1.6 ≤0.02 ≤0.02 ≤0.8

[0051] Table 2 Strength design value table

[0052]

[0053]

[0054] According to the results of the Midas overall analysis, the most unfavorable combination of internal forces is selected, and the axial force, bending moment, shear force, and torque are converted into loads in the overall coordinate system, and applied through the virtual MASS21 unit and rigid connection with the end node; the column head node, which mainly bears axial pressure, converts the pressure into surface pressure and applies it to the pressure-bearing surface. The finite element analysis of the cast steel node uses solid units, and the calculation of the present invention uses the 10-node tetrahedral solid unit SOLID92 in ANSYS.

[0055] Conclusion: According to the calculation results, the maximum von-mises stress at the node is 165.4N / mm 2 <405N / mm 2 The main manifestation is the hole wall bearing pressure, with a maximum deformation of 0.34mm; the maximum stress in other parts is 115.3N / mm 2 , less than the design strength 1.1*230 / 0.9=281N / mm 2 , meeting the requirements.

[0056] To sum up, with the aid of the above-mentioned technical scheme of the present invention, by providing the guide limit assembly 5, the connecting ear 6 and the connecting tube 8, not only can the guide limit assembly 5 play a guiding and limiting effect in the process of connecting with the steel pipe, but also the connecting tube 8 can facilitate the connection with the inclined tube. At the same time, due to the presence of the connecting ear 6 and the connecting tube 8, the inclined tube can achieve a small range of swing effect, and then can play a certain anti-seismic effect, so as to better meet the connection requirements between steel pipes.

[0057] In addition, by providing a guide and limit assembly 5, not only can the guide ring 501 play a guiding effect on the connection of the steel pipe, but also the spring 506 and the limit bar 503 can play a certain limiting effect on the connected steel pipe, thereby better meeting the connection requirements between steel pipes.

[0058] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A movable steel structure special-shaped cast steel node, characterized in that: It comprises a first support tube (1), a second support tube (2) and a third support tube (3) are arranged in sequence on the outer side of the middle part of the first support tube (1), and a fourth support tube (4) is arranged between the second support tube (2) and the third support tube (3); Both ends of the first support tube (1), the top end of the second support tube (2), the top end of the third support tube (3) and the top end of the fourth support tube (4) are provided with guide limiter components (5); Two groups of connecting ears (6) are also provided on the outer side of the middle part of the first supporting tube (1), and the connecting ears (6) are located on the back side of the middle part of the first supporting tube (1). One end of the connecting ears (6) away from the first supporting tube (1) is movably connected to a connecting tube (8) matching therewith, and a swing angle of 3°-5° is formed between the connecting tube (8) and the connecting ears (6).

2. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: The diameters of the first support tube (1), the second support tube (2) and the fourth support tube (4) gradually decrease, and the diameters of the second support tube (2) and the third support tube (3) are equal.

3. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: The second support tube (2), the third support tube (3) and the fourth support tube (4) are all arranged in different planes and perpendicular to the first support tube (1).

4. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: The second support tube (2) and the third support tube (3) are arranged at an obtuse angle, and the fourth support tube (4) is located in the middle of the second support tube (2) and the third support tube (3).

5. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: A plurality of fixing rings (7) are arranged inside the first supporting tube (1), the second supporting tube (2), the third supporting tube (3) and the fourth supporting tube (4).

6. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: The guide and limiter assembly (5) comprises guide rings (501) installed at both ends of the first support tube (1), the top of the second support tube (2), the top of the third support tube (3) and the top of the fourth support tube (4); a plurality of installation grooves (502) are evenly arranged on the outside of the guide ring (501); and the inside of each installation groove (502) is provided with a limiter strip (503) matched therewith; Limit blocks (504) are provided at both ends of the limit strip (503) close to the inner wall of the installation groove (502), a plurality of rectangular grooves (505) are evenly opened on one side of the limit strip (503) close to the inner wall of the installation groove (502), and springs (506) are provided inside the rectangular grooves (505).

7. The movable steel structure special-shaped cast steel node according to claim 6, characterized in that: The diameters of the guide rings (501) on the first support tube (1), the second support tube (2) and the fourth support tube (4) gradually decrease, and the diameters of the guide ring (501) on the second support tube (2) and the guide ring (501) on the third support tube (3) are equal.

8. The movable steel structure special-shaped cast steel node according to claim 7, characterized in that: The diameters of the guide rings (501) on the first support tube (1), the second support tube (2) and the fourth support tube (4) are all smaller than their own diameters.

9. The movable steel structure special-shaped cast steel node according to claim 6, characterized in that: The side of the limiting strip (503) away from the mounting groove (502) is evenly provided with anti-slip grooves (507).

10. The movable steel structure special-shaped cast steel node according to claim 1, characterized in that: The two groups of connecting ears (6) are arranged at an obtuse angle, the connecting ears (6) and the first support tube (1) are arranged at an obtuse angle, and the connecting ears (6) are arranged inclined from the first support tube (1) towards a direction away from the first support tube (1).

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