A kind of integral casting connecting node for multi-bar truss structure

Abstract

The application discloses a kind of integral casting connecting nodes for multi-bar truss structure, including the node body of being integrally cast by casting aluminum alloy, at least one main truss connecting part and at least one branch truss connecting part arranged on the node body.Main truss connecting part is connected with aluminum alloy main truss bar member with I-shaped section by bolt, and the main truss bar member is not truncated when connecting;Branch truss connecting part is connected with aluminum alloy branch truss bar member by bolt.The transition area of main truss connecting part and main truss bar member connection is provided with stepped transition section gradually reducing in thickness along the connecting direction, for compensating the strength difference between cast aluminum alloy and extruded aluminum alloy, realizing equal strength connection with main truss bar member.The application can ensure the continuous stress of main truss bar member, avoid stress concentration, realize the equal strength connection of node and bar, compact structure, convenient assembly.

Description

Technical Field

[0001] This invention relates to the field of spatial structure connection node technology, and more specifically, to an integrally cast connection node for truss systems, particularly aluminum alloy truss structures. Background Technology

[0002] In recent years, with the continuous development of building structures towards lightweight, high durability, and recyclability, aluminum alloy materials, due to their significant advantages such as light weight, strong corrosion resistance, and high recyclability, have been increasingly widely used in various spatial truss structures and grid shell structures. In engineering practice, common aluminum alloy components are mainly manufactured using extrusion molding, a process that produces materials with regular cross-sections and good mechanical properties. However, aluminum alloy materials are prone to heat-affected zones during welding, leading to a significant reduction in material strength. Therefore, in actual engineering projects, bolted connections are often used instead of welding for the connections between aluminum alloy components. For truss nodes with multi-directional stress characteristics, traditional mechanical assembly methods often require multiple connecting plates, a large number of bolts, and other auxiliary connecting components. This connection method not only greatly increases the complexity of the node structure but also places extremely high demands on processing and installation accuracy, resulting in low construction efficiency. Against this backdrop, using casting technology to manufacture spatial structural nodes has gradually become a feasible technical approach. Cast nodes can achieve complex spatial geometry through one-time forming, thus enabling more efficient connection of multi-directional truss members and simplifying the construction of the node area.

[0003] The closest prior art to this invention is Chinese patent CN101974938A, which discloses a "pole-mounted body-node aluminum alloy triangular and rectangular spatial truss structure". In this technical solution, a slot is opened in three directions on the node body. All aluminum alloy members (including main truss members) converging at the node body are cut off and inserted into the corresponding slots, and then fastened together with bolts or rivets. However, this structure has obvious defects: First, the main truss members are cut off at the nodes, which artificially interrupts the originally continuous force transmission path, easily causing severe stress concentration and stiffness abrupt changes near the nodes, weakening the overall load-bearing performance of the structure. Second, this prior art does not consider the strength matching problem between the cast node material and the extruded member material. Generally, the strength of cast aluminum alloy is lower than that of extruded aluminum alloy. When the two are directly connected by bolts, the cross-sectional properties of the connection area are prone to incompatibility, resulting in uneven local stress distribution, which in turn affects the load-bearing capacity of the node. Furthermore, Chinese patent CN111021535A discloses an integrated node connection component for aluminum alloy trusses, which uses a Y-shaped connecting plate and a diaphragm to form an interlocking space. However, this document mainly addresses the issue of adjustable angles for diagonal web members, without addressing the design of preventing the main truss from being cut off, nor providing technical guidance for compensating for the strength differences between cast and extruded materials. Chinese patent CN111364362A relates to a fully welded integral node steel pipe truss, whose materials and connection processes differ from this invention. Therefore, there is an urgent need in the prior art for a novel truss connection node that can ensure continuous stress on the main truss and achieve equal-strength connections. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned problems existing in the prior art and provide an integrally cast connection node for a multi-member truss structure that can ensure continuous stress on the main truss, achieve equal strength connection, and has a compact structure and convenient assembly.

[0005] To solve the above-mentioned technical problems, the technical solution proposed in this application is as follows: This invention provides an integrally cast connection node for a multi-member truss structure, comprising: A node body, wherein the node body is integrally cast from cast aluminum alloy; At least one main truss connection is provided on the node body and connected to an aluminum alloy main truss member by bolts, and the main truss member is not cut off during the connection; At least one truss connection is provided on the node body and connected to an aluminum alloy support truss member by bolts; The main truss member has an I-shaped cross section. The transition area where the main truss connection part connects to the main truss member is provided with a stepped transition cross section whose thickness gradually decreases along the connection direction, so as to compensate for the strength difference between cast aluminum alloy and extruded aluminum alloy and achieve an equal strength connection with the main truss member.

[0006] Furthermore, the truss member has an angular cross-section.

[0007] Furthermore, the shape of the node body is constructed as a polyhedron to simultaneously accommodate the connection ends of the main truss members and the support truss members.

[0008] Furthermore, the node body is applicable to two-dimensional truss connection scenarios, including a vertical main truss connection part and two branch truss connection parts, wherein the two branch truss connection parts are symmetrically or at a predetermined angle connected to the side of the vertical main truss connection part.

[0009] Furthermore, the node body is applicable to three-dimensional truss connection scenarios, including a vertical main truss connection part, a horizontal main truss connection part and two branch truss connection parts. The vertical main truss connection part and the horizontal main truss connection part are arranged intersectingly, and the two branch truss connection parts are connected to the side of the horizontal main truss connection part.

[0010] Furthermore, there are multiple bolts, which pass through bolt holes opened on the main truss connection part and the support truss connection part, and are fastened to the bolt holes on the corresponding main truss members and the support truss members.

[0011] Furthermore, the thickness of each step of the stepped transition section is configured such that the strength of the cast aluminum alloy section at that location is substantially equal to the strength of the section at the corresponding location of the connected extruded aluminum alloy main truss member.

[0012] Furthermore, the strength value of the cast aluminum alloy is lower than the strength value of the extruded aluminum alloy used in the main truss members and the support truss members.

[0013] Furthermore, the node body is a polyhedron, and the angles of its connecting surfaces are determined according to the spatial intersection angles of the truss members connected to it.

[0014] Furthermore, the wall thickness of the node body is optimized based on the stress calculation results to achieve structural lightweighting.

[0015] Compared with the prior art, the present invention achieves the following beneficial technical effects: First, this invention ensures the continuity of force distribution in the main truss. By employing bolted connections that do not interrupt the main truss, continuous force flow is achieved between the nodes and the main members, avoiding stress concentration and abrupt stiffness changes caused by member interruptions, and significantly improving the overall structural performance. Second, this invention enhances the overall strength and stiffness of the structure. By setting a stepped transition section in the connection transition area between the node and the main truss, the material strength difference between cast aluminum alloy and extruded aluminum alloy is cleverly compensated, achieving an equal-strength connection between the two and avoiding the formation of weak points in the connection area. Third, this invention achieves structural integration and convenient assembly. The node body is integrally cast, reducing the welding and multi-part assembly processes required by traditional connection methods, which not only improves manufacturing precision but also greatly improves on-site assembly efficiency. Fourth, this invention has a wide range of applications. By designing two node forms applicable to two-dimensional trusses and space trusses, it can be flexibly selected according to different engineering needs, exhibiting strong versatility. Fifth, this invention combines the advantages of lightweight and recyclability. The entire structure is made of aluminum alloy, which not only achieves lightweight structure but also has excellent recyclability, fully in line with the technological development direction of green building and sustainable development. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the integrated cast aluminum node structure (two-dimensional) of the present invention; Figure 2 This is a schematic diagram of the integrated cast aluminum node structure (three-dimensional) of the present invention; Figure 3 is a schematic diagram of the connection between the integrated cast aluminum node structure and the aluminum alloy component of the present invention; wherein, (a) is a schematic diagram of the connection between the cast aluminum node and the component applicable to two-dimensional truss connection, and (b) is a schematic diagram of the connection between the cast aluminum node and the component applicable to three-dimensional truss connection.

[0018] In the figure, the meanings of the attached labels are as follows: Node body 1, main truss connection part 2, support truss connection part 3, stepped transition section 4, transverse main truss connection part 5. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides an integrally cast connection node for multi-member truss structures. Its core design concept lies in: forming a complex node geometry through an integrated casting process to accommodate the spatial convergence of multiple members in the truss structure; simultaneously, bolting the node without cutting off the main truss to ensure the continuity of the main load-bearing members; and furthermore, by designing a stepped transition section in the connection area, compensating for the strength difference between cast aluminum alloy and extruded aluminum alloy, achieving equal strength design for the entire connection system, thereby ensuring the safety and reliability of the structure.

[0021] Please see Figure 1 , Figure 2 As shown in Figure 3, in one embodiment of this application, the integrally cast connection node of the multi-member truss structure includes a node body 1. This node body 1 is the core of the entire connection system, responsible for effectively converging and transmitting internal forces from truss members of different directions and specifications. To achieve good mechanical properties and a complex shape, the node body 1 is made of cast aluminum alloy and integrally formed using an integral casting process. The advantage of this integral forming is that it can accurately form various complex spatial geometries without subsequent welding or assembly, thus avoiding the strength reduction problem caused by welding and ensuring the integrity and dimensional accuracy of the node itself. The node body 1 is provided with at least one main truss connection part 2 and at least one branch truss connection part 3. The main truss connection part 2 is connected to an aluminum alloy main truss member by bolts, and in making this connection, the main truss member is not cut off; that is, the main truss member maintains its complete length and cross-section, and the node body 1 is attached to the continuous main member by bolts. The branch truss connection part 3 is connected to the aluminum alloy branch truss member by bolts. Furthermore, in the transition area where the main truss connection 2 connects to the main truss members, a stepped transition section 4 with a gradually decreasing thickness along the connection direction is provided. This design aims to compensate for the strength difference between cast aluminum alloy and extruded aluminum alloy, achieving a connection of equal strength between the node and the main truss members. In this way, continuous force flow transmission between the node and the main members is achieved, avoiding stress concentration and abrupt stiffness changes caused by member interruptions, while simultaneously compensating for the strength difference between cast and extruded aluminum alloys.

[0022] In one embodiment of this application, the cross-sectional form of the members connected to the node is optimized. Specifically, considering that the main truss mainly bears large bending moments and shear forces, an I-shaped cross-section with superior stress performance is adopted. The I-shaped cross-section has the advantages of high bending stiffness and reasonable material distribution, and can efficiently bear the main load. The support truss mainly bears axial forces, and its stress distribution is relatively simple, so an angled cross-section with simpler construction and easier connection is adopted. The shape and size of the main truss connection part 2 and the support truss connection part 3 on the node body 1 are matched with the members with these two different cross-sections to ensure the effectiveness and sealing of the connection.

[0023] In one embodiment of this application, in order to simultaneously accommodate and connect multiple members converging in different directions, the overall shape of the node body 1 is constructed as a polyhedron. Each face of this polyhedron, or its extension, constitutes a connection for docking with the end of a truss member. The spatial orientation and angle of each connection face on the polyhedron are precisely determined based on the actual spatial convergence angle of the truss members connected to it in the structure, thereby ensuring that the node can achieve a smooth connection with the members without geometric conflicts and minimizing additional bending moments.

[0024] Please pay close attention. Figure 1 As shown in Figure 3(a), in one embodiment of this application, the node body 1 is designed for use in two-dimensional truss connection scenarios. In this embodiment, the node body 1 is constructed to extend in a main plane. Specifically, the node body 1 includes a vertical main truss connection 2 and two branch truss connection parts 3. The vertical main truss connection 2 is used to connect with vertically arranged main truss members having an I-shaped cross-section. The two branch truss connection parts 3 extend from the sides of the vertical main truss connection 2 and are used to connect with two branch truss members having a certain included angle. Depending on the actual structural design requirements, the two branch truss connection parts 3 can be symmetrically arranged with respect to the central axis of the vertical main truss connection 2, or they can be arranged at a predetermined asymmetrical angle to adapt to different truss grid shapes.

[0025] Please pay close attention. Figure 2As shown in Figure 3(b), in one embodiment of this application, the node body 1 is designed to be suitable for three-dimensional (spatial) truss connection scenarios. In this embodiment, the node body 1 is constructed as a more complex spatial polyhedron. Specifically, the node body 1 includes a vertical main truss connection 2, a horizontal main truss connection 5, and two support truss connections 3. The vertical main truss connection 2 and the horizontal main truss connection 5 are spatially intersecting; for example, they can be orthogonal or intersect at other angles, respectively used to connect the vertical and horizontal I-shaped cross-section main truss members. The intersection of these two main truss connections constitutes the main load-bearing core of the spatial truss. The two support truss connections 3 are connected to the sides of the horizontal main truss connection 5 and may have a specific orientation in space, used to connect diagonal braces or web members in space.

[0026] In one embodiment of this application, bolted connection is a specific implementation of the invention. Multiple bolt holes are pre-drilled on the main truss connection portion 2 and the support truss connection portion 3 of the node body 1, according to the needs of structural stress calculations. Correspondingly, bolt holes are also drilled at corresponding positions on the I-shaped aluminum alloy main truss members and the angled aluminum alloy support truss members to be connected. During installation, the members are aligned with the connection portions of the node body 1, and then multiple high-strength bolts are passed through these bolt holes and tightened, thereby achieving a reliable connection between the node and the members. Using bolted connection instead of welding avoids the strength loss problem caused by aluminum alloy welding, and also facilitates on-site assembly and future disassembly and maintenance.

[0027] To address the critical contradiction that cast aluminum alloy materials (typically used for joints) have lower strength than extruded aluminum alloy materials (typically used for members), this invention introduces a groundbreaking structure—a stepped transition section 4—on the main truss connection 2. For details, please refer to [link to specific structural description]. Figure 1 and Figure 2 The diagram shows a partially enlarged view. In one embodiment of this application, the stepped transition section 4 is disposed in the transition region extending from the root (where it connects to the main body 1) of the main truss connection 2 to its end (where it connects to the main truss member). Along the connection direction from the main body 1 to the main truss member, the wall thickness of this transition region is not uniform, but rather presents a stepped shape that decreases gradually. By carefully designing the thickness value of each step, the cross-sectional strength determined by the cast aluminum alloy and its cross-sectional thickness at any cross-section along the connection direction can be made substantially equal to the internal force to be transmitted at that cross-section location (which is determined by the cross-sectional strength of the continuous main truss member connected thereto). This achieves the design goal of "equal strength connection," that is, the strength of the entire connection region is comparable to the strength of the main truss member itself, and there will be no obvious weak areas in load-bearing capacity due to the presence of the node.

[0028] In one embodiment of this application, the design of the aforementioned stepped transition section 4 is particularly important because the strength of cast aluminum alloy is typically lower than that of extruded aluminum alloy used in the main truss members and support truss members. Since the extruded aluminum alloy members themselves have higher strength, the internal forces they need to bear can be borne by their own cross-sections. Therefore, the thickness of the connection node can be reduced accordingly in a stepped manner, ultimately matching the wall thickness of the extruded aluminum alloy member or the thickness of the connecting plate at the connection end.

[0029] In one embodiment of this application, to adapt to the ever-changing truss geometry, the node body 1 is designed as a polyhedron. The angles of its connecting surfaces are not arbitrarily set, but precisely determined according to the spatial intersection angles of the truss members connected to it, achieving a "tailor-made" connection and ensuring the smooth transmission of force.

[0030] In one embodiment of this application, to further optimize structural performance, the wall thickness of the node body 1, except at the stepped transition section 4, can also be optimized based on the stress calculation results such as finite element analysis. Without affecting the structural bearing capacity and stiffness, the wall thickness of non-critical areas can be appropriately reduced to lighten the weight of the node itself, thereby achieving the goal of lightweighting the entire truss structure.

[0031] In summary, this invention provides an integrally cast connection node for multi-member truss structures that is ingeniously conceived, structurally sound, and boasts superior performance. It ensures the continuity of force flow through bolted connections that do not sever the main truss; it adapts to the stress requirements of different members through targeted cross-sectional designs (I-beams, angle steel); it achieves precise forming and efficient manufacturing of complex geometries through integral casting; and, in particular, it cleverly solves the challenge of equal-strength connections between materials of different strengths by setting a stepped transition section at the main truss connection. These technical features work synergistically to form a complete technical solution, effectively overcoming many shortcomings of existing technologies and providing a solid technical foundation for the application of aluminum alloy truss structures in larger spans and more complex spatial configurations.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A monolithically cast connection node for a multi-member truss structure, characterized in that, include: A node body (1) is integrally cast from cast aluminum alloy. At least one main truss connection part (2) is provided on the node body (1) and is connected to an aluminum alloy main truss member by bolts, and the main truss member is not cut off during connection; At least one truss connection part (3) is provided on the node body (1) and is connected to an aluminum alloy support truss member by bolts; The main truss member has an I-shaped cross section. The transition area where the main truss connection part (2) connects with the main truss member is provided with a stepped transition section (4) whose thickness gradually decreases along the connection direction, so as to compensate for the strength difference between cast aluminum alloy and extruded aluminum alloy and achieve an equal strength connection with the main truss member.

2. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The support truss members have angular cross sections.

3. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The shape of the node body (1) is constructed as a polyhedron for simultaneously accommodating the connection ends of the main truss members and the support truss members.

4. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The node body (1) is suitable for two-dimensional truss connection scenarios, including a vertical main truss connection part (2) and two branch truss connection parts (3). The two branch truss connection parts (3) are symmetrically or connected to the side of the vertical main truss connection part (2) at a predetermined angle.

5. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The node body (1) is suitable for three-dimensional truss connection scenarios, including a vertical main truss connection part (2), a horizontal main truss connection part (5) and two support truss connection parts (3). The vertical main truss connection part (2) and the horizontal main truss connection part (5) are arranged in a cross manner, and the two support truss connection parts (3) are connected to the side of the horizontal main truss connection part (5).

6. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The bolts are multiple and pass through bolt holes opened on the main truss connection part (2) and the support truss connection part (3) respectively, and are fastened to the bolt holes on the corresponding main truss members and the support truss members.

7. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The thickness of each step of the stepped transition section (4) is configured such that the strength of the cast aluminum alloy section at that location is substantially equal to the strength of the section at the corresponding location of the connected extruded aluminum alloy main truss member.

8. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The strength value of the cast aluminum alloy is lower than that of the extruded aluminum alloy used in the main truss members and the support truss members.

9. The integrally cast connection node for a multi-member truss structure according to claim 1, characterized in that, The node body (1) is a polyhedron, and the angles of its connecting surfaces are determined according to the spatial intersection angles of the truss members connected to it.

10. The integrally cast connection node for a multi-member truss structure according to any one of claims 1 to 9, characterized in that, The wall thickness of the node body (1) is optimized based on the stress calculation results to achieve structural lightweighting.

Images