A new type of cast steel joint interface

Abstract

The present invention relates to the field of building structures using cast steel joints, and particularly to a novel cast steel joint interface. The interface includes: a cast steel joint, a steel member, and a connection weld between the two; a connection port external convex is provided on the cast steel joint, a reinforcing steel plate is provided on the steel member (on the outer surface of the steel member), and both the connection port external convex and the reinforcing steel plate are located at the connection weld. The present invention ensures the equal-strength connection of the interface when the cast steel joint is connected to the steel member, and has the advantages of simple structure, reliable force-bearing, and simple construction.

Description

Technical Field

[0001] The present invention relates to the field of building structures using cast steel joints, and in particular to a new type of cast steel joint interface. Background Art

[0002] Cast steel joints used in construction projects have been adopted in more and more projects because they avoid large residual stresses when multiple members are directly welded in a multi-member intersection, have a large degree of freedom in joint design, and have an aesthetic appearance.

[0003] According to Article 3.2.1 of the "Technical Specification for Application of Cast Steel Joints" CECS235-2008, the weldable cast steel materials currently used for cast steel joints mainly include ZG230-450H, ZG275-485H, G17Mn5QT, G20Mn5N, and G20Mn5QT, and their strength design values are shown in Table 1.

[0004] Table 1 Design strength indexes of weldable cast steel (N / mm 2 )

[0005]

[0006] According to the "Steel Structure Design Standard" GB50017-2017, the main materials and strength parameters currently used for steel structures are shown in Table 2. It can be seen from Table 1 and Table 2 that the strength design values of cast steel materials are not much different from those of Q235, and are all less than Q355, Q390, Q420, and Q460.

[0007] Table 2 Design strength indexes of steel materials (N / mm 2 )

[0008]

[0009] The conventional practice when a cast steel joint is connected to a steel member is as Figure 1 shown. When the steel member uses Q355, Q390, Q420, or Q460 steel, the wall thickness of the member is t 1 . To solve the problem of low strength of the cast steel joint material, the wall thickness of the cast steel joint is often thickened to t 2 , that is, t 1 is less than t 2 . Although the wall thickness t 2 of the cast steel joint is relatively thickened compared to the wall thickness t 1 of the member, the thickness at the connection 03 between the cast steel joint 01 and the steel member 02 is still t 1 , and only the thickness t 1 of the cast steel is stressed, and an equal-strength connection cannot be achieved, resulting in a low connection strength of the member strength and a weak part at the connection.

[0010] The information disclosed in this background section is only intended to enhance the understanding of the overall background of the present invention and should not be regarded as an admission or any form of implication that this information constitutes prior art known to those skilled in the art. Summary of the Invention

[0011] The object of the present invention is to provide a new type of cast steel node interface. This new form of the interface can achieve equal-strength connection at the interface position, and at the same time provides a prerequisite for selecting welding consumables for the connection weld in accordance with Article 7.1.1 of the Technical Specification for Application of Cast Steel Nodes CECS 235-2008. By selecting welding consumables that match the low-strength base material, the ductility performance of the weld at the interface is ensured.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] The present invention provides a new type of cast steel node interface, including: a cast steel node, a steel member, and a connection weld between the two; a connection port outer boss is provided on the cast steel node, a reinforcing steel plate is provided on the steel member, and both the connection port outer boss and the reinforcing steel plate are located at the connection weld.

[0014] As a further technical solution, the connection port outer boss is integrally cast with the cast steel node.

[0015] As a further technical solution, the reinforcing steel plate is welded to the steel member.

[0016] As a further technical solution, the length of the connection port outer boss should not be less than 6 times its height.

[0017] As a further technical solution, the length of the reinforcing steel plate should not be less than 6 times its height and not less than 50 mm.

[0018] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0019] 1. Simple structure and reliable force. A region with height t and length L is newly added at the interface position of the cast steel node. A reinforcing steel plate with thickness t and length L is added outside the steel plate to ensure that there is cast steel with height t at the interface between the cast steel and the steel member, achieving equal-strength connection at the connection interface position. 4 height, L 4 length area, adding a reinforcing steel plate with thickness t 3 and length L 3 outside the steel plate to ensure that there is cast steel with height t 2 at the interface between the cast steel and the steel member, achieving equal-strength connection at the connection interface position.

[0020] 2. Simple construction: The newly added area form of the cast steel joint is simple and is cast together during the casting of the joint, without increasing the casting difficulty. The reinforcing steel plate outside the steel plate is welded outside the component, and it can be applied regardless of the size of the member and any cross-sectional shape, with a large construction space and convenient construction. Brief Description of the Drawings

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Schematic diagram of the interface structure of the cast steel joint in the prior art;

[0023] Figure 2 Schematic diagram of the structure of the new cast steel joint interface provided by the present invention;

[0024] Figure 3 For Figure 2 Enlarged view of part A in

[0025] Wherein: 01 is the cast steel joint, 02 is the steel member, 03 is the connection part, 1 is the cast steel joint, 2 is the convex platform outside the connection port, 3 is the reinforcing steel plate, 4 is the steel member, 5 is the connection weld, and 6 is the connection weld. Detailed Embodiments

[0026] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0030] Combined Figure 1 and Figure 2 As shown, this embodiment provides a new type of cast steel node interface, including: a cast steel node 1, a steel member 4, and a connection weld 6 therebetween; a connection port outer convex platform 2 is provided on the cast steel node 1, a reinforcing steel plate 3 is provided on the steel member 4, and both the connection port outer convex platform 2 and the reinforcing steel plate 3 are located at the connection weld 6.

[0031] In this embodiment, as a further technical solution, the connection port outer convex platform 2 is integrally cast with the cast steel node 1 without increasing the casting difficulty.

[0032] In this embodiment, as a further technical solution, the reinforcing steel plate 3 and the steel member 4 are welded and connected through a connection weld 5, which is applicable to any rod size and any cross-sectional shape, with a large construction space and convenient construction.

[0033] Add a region with height t 4 and length L 4 at the connection port position of the cast steel node, so that the thickness at the connection port outer convex platform 2 of the cast steel node is t 2 , satisfying that the strength of the connection port outer convex platform of the cast steel node is not lower than the strength of the connected steel member, that is, t 2 ×f 2 ≥t 1 ×f 1 , where f 1 represents the tensile, compressive, flexural design strength, or shear design strength of the component steel; f 2 represents the tensile, compressive, flexural design strength, or shear design strength of the cast steel. For the length L 4 of the newly added cast steel region, it needs to be determined according to the cast steel material and the force. Preferably, L 4 is not less than 6t 4 .

[0034] Add a thickness t to the outside of the steel member 3 and a length L 3 of the reinforcing steel plate 3 to ensure that there is a steel plate with a height of t at the interface between the cast steel joint and the steel plate. The reinforcing steel plate 3 is connected to the steel structure 4 through the connecting weld 5. The length L3 of the reinforcing steel plate 3 needs to be determined according to the material and stress of the reinforcing plate. Preferably, L 5 is not less than 6t 3 and not less than 50 mm. 3 The relevant parameters need to be determined according to the stress. For example: when the steel member only bears axial force, for t

[0035] and t 3 and t 5 the thickness can be calculated according to the following formula:

[0036] The tensile strength of the connecting weld 6 at the interface between the cast steel joint and the steel member is or the compressive strength and the shear strength is The included angle between the weld and the steel member is a; the weld at the connection between the reinforcing steel plate and the steel member is a fillet weld, and the design values of the tensile, compressive and shear strengths are Assume that the weld length between the steel member 4 and the cast steel joint 1 is L.

[0037] First, take the example of bearing tension:

[0038] The bearing capacity of the connecting weld 6 and the cast steel joint with equal strength connection is N 0 :

[0039]

[0040] The axial force N 1 transmitted by the connecting weld 6 to the steel member 4 is:

[0041]

[0042] The axial force N 2 transmitted by the weld 6 to the reinforcing steel plate 3 is:

[0043]

[0044] Determine the thickness of the reinforcing steel plate 3 as t according to the weld strength between the connecting weld 6 and the reinforcing steel plate 3 31 :

[0045] Determine the thickness of the reinforcing steel plate 3 as t according to the weld tensile strength 3a :

[0046]

[0047] Determine the thickness of the reinforcing steel plate 3 as t according to the weld shear strength3b :

[0048]

[0049] t 31 = max(t 3a , t 3b )

[0050] Axial force N 2 is transmitted to the position of the connecting weld 5, and the thickness of the reinforcing steel plate 3 is determined as t according to the strength of the connecting weld 5 32 :

[0051] The connecting weld 5 is a fillet weld, and the design values of the tensile, compressive and shear strengths are

[0052]

[0053] (β = 1.22 under static load f , β = 1.0 under dynamic load f ).

[0054] Then the thickness t of the reinforcing steel plate 3 3 is:

[0055] t 3 = max(t 31 , t 32 );

[0056] t 5 = t 1 + t 3 ;

[0057] When under pressure, replace the tensile strength of with the compressive strength

[0058] In summary, through the adjustment of the form at the interface between the cast steel joint and the steel member, the present invention realizes that the total thickness of the two sides of the cast steel (1 and 2) at the interface is not less than the thickness t of the cast steel joint 1 2 , and the total thickness of the steel materials (3 and 4) is not less than t 5 , realizing the equal-strength connection at the connection interface position.

[0059] The present invention ensures the equal-strength connection at the interface when connecting the cast steel joint and the steel member, and has the advantages of simple structure, reliable force-bearing and simple construction.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A new type of cast steel joint interface, including: a cast steel joint, a steel member, and a connection weld between the two; characterized in that a connection port external convex platform is provided on the cast steel joint, a reinforcing steel plate is provided on the outer surface of the steel member, and both the connection port external convex platform and the reinforcing steel plate are located at the connection weld; Add t at the connection port position of the cast steel joint 4 height, L 4 length area, so that the thickness at the outer boss of the connection port of the cast steel joint is t 2 , ensuring that the strength of the outer boss of the connection port of the cast steel joint is not lower than that of the connected steel member, that is, t 2 ×f 2 ≥t 1 ×f 1 , f 1 represents the tensile, compressive and flexural design strength, or shear design strength of the structural steel; f 2 represents the tensile, compressive and flexural design strength, or shear design strength of the cast steel; for the length L 4 of the newly added cast steel area, it needs to be determined according to the cast steel material and the force; Increase the thickness t on the outside of the steel member 3 and the length L 3 of the reinforcing steel plate to ensure that there is a steel plate with a height of t 5 at the interface between the cast steel joint and the steel plate. The reinforcing steel plate is connected to the steel structure through a connecting weld. The length L3 of the reinforcing steel plate needs to be determined according to the material and stress of the reinforcing plate.

2. The new type of cast steel joint interface according to claim 1, characterized in that the connection port external convex platform is integrally cast with the cast steel joint.

3. The new type of cast steel joint interface according to claim 1, characterized in that the reinforcing steel plate is welded to the steel member.

4. The new type of cast steel joint interface according to claim 1, characterized in that the length of the connection port external convex platform is not less than 6 times its height.

5. The new type of cast steel joint interface according to claim 1, characterized in that the length of the reinforcing steel plate is not less than 6 times its height and not less than 50 mm.

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