Large-span roof tensile membrane structure and design method thereof

Abstract

The invention relates to the technical field of structural design of constructional engineering, in particular to a large-span roof tensile membrane structure and a design method thereof. The large-span roof tensile membrane structure comprises at least two non-drainage boundaries and one drainage boundary, the tension film is tensioned between the non-drainage boundary and the drainage boundary; the non-drainage boundaries are located at the same elevation or at different elevations; the drainage boundary is in a concave arch shape. The tensile membrane structure does not need to depend on supporting components such as arches, cables and supporting rods, the negative Gaussian curved surface is formed by conducting concave design on the membrane boundary, the drainage path is formed in the concave direction, and organized drainage of the tensile membrane structure is achieved. Meanwhile, under the action of prestress, the membrane structure of the negative Gaussian curved surface has the structural rigidity meeting the use requirement. According to the corresponding design method, the sunken size of the outer boundary of the tensile membrane can be determined on the basis of roof structure geometry of different shapes. According to the stretch-draw membrane structure and the design method thereof, the influence and limitation of a traditional membrane structure model and an internal supporting component on the building effect can be avoided, the requirements for the transparent and light building effect are met to the maximum extent, and meanwhile water accumulation of the membrane structure is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of structural design of building engineering, and in particular to a large-span roof tensioned membrane structure and a design method thereof. Background Art

[0002] Compared with traditional structures, membrane structures have the characteristics of light weight, large span, convenient construction, good light transmittance, and good self-cleaning. At the same time, membrane structures are flexible structures, and their adaptability to deformation is much better than that of rigid enclosure structures. Therefore, membrane structures are often used as the preferred roof enclosure system for large-span cable structure roofs and are widely used in the roof structures of large-span buildings such as stadiums. The difference between membrane structures and traditional rigid structures is first manifested in that the material itself does not have rigidity and shape, and prestress must be applied to obtain the rigidity and shape of the structure. Common tensile membrane structure unit shapes include negative Gaussian curvature shapes such as hyperbolic paraboloid saddles, conical umbrellas, or double umbrellas. These shapes are assisted by supporting components such as arches, cables, and struts inside the membrane. However, with the development of construction technology, the common shapes of tensile membrane structure units and the components that support their shapes can no longer meet architects' pursuit of architectural shapes, especially the shapes and effects of large-span roofs.

[0003] Tensile membrane structures without internal supporting components have greater adaptability in realizing architectural shapes. Compared with rigid enclosure structures, they can also significantly reduce the weight of the roof, reduce the number of roof structural components, and improve the lightness and transparency of the building roof. However, membrane structures without internal supporting components have the following problems: the membrane material can only withstand the tension within the membrane surface, and the load in the direction perpendicular to the membrane surface is converted into the tension within the membrane surface through the deformation of the membrane surface. Unlike traditional tensile membrane structures that rely on arches, struts or cables to form negative Gaussian curvature shapes such as hyperbolic paraboloid saddles and conical umbrellas to avoid water accumulation, the curvature of the membrane surface without internal supporting components is small, and the deformation under vertical loads is easy to form concave pits, resulting in water and snow accumulation, and then producing a "water pocket" effect, resulting in a vicious cycle of increasing deformation and load, creating safety hazards, and greatly limiting the engineering application of this type of tensile membrane structure.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0005] In view of the problems existing in the prior art, one of the objects of the present invention is to provide a large-span roof tensile membrane structure; the second object of the present invention is to provide a design method for such a large-span roof tensile membrane structure.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A long-span roof tensile membrane structure, comprising: no less than 2 non-drainage boundaries and 1 drainage boundary;

[0008] A tensile membrane is stretched between the non-drainage boundary and the drainage boundary;

[0009] The non-drainage boundaries are located at the same elevation, or at different elevations;

[0010] The drainage boundary is in a concave arch shape.

[0011] Furthermore, the arch is a circular arc, a parabola, an ellipse or a Nurbs curve.

[0012] Furthermore, there is only one drainage point on the concave arch, and its elevation is at the lowest point of the entire tensile membrane surface.

[0013] Furthermore, the tensile membrane structure is connected to the non-drainage boundary and the drainage boundary through two types of membrane surface nodes.

[0014] Furthermore, the membrane surface nodes include U-shaped connection nodes and anti-slip connection nodes; wherein,

[0015] The U-shaped connection node provides a tensile constraint in a direction perpendicular to the boundary for the tensile membrane surface;

[0016] The anti-slip connection node provides the tensile membrane surface with a tensile constraint in a direction perpendicular to the boundary, and also provides a sliding constraint parallel to the boundary direction;

[0017] The U-shaped connection nodes and the anti-slip connection nodes are arranged according to the force requirements of the tensile membrane structure.

[0018] Furthermore, the angle between the line connecting the nearest points of the adjacent contour lines of the tensile membrane structure and the horizontal plane is not less than the minimum drainage slope of the membrane material used. .

[0019] A design method for a large-span roof tensile membrane structure comprises the following steps:

[0020] S1. Determine all non-drainage boundaries and drainage boundaries according to the building shape. The non-drainage boundaries are recorded as , is the number of boundaries; the drainage boundary is recorded as , is the number of iterations;

[0021] S2, non-drained boundary and drainage boundaries Construct a zero-state model of the tensile membrane based on the preset membrane surface prestress The shape analysis is performed with the deadweight of the membrane structure to calculate the equilibrium state of the membrane surface at this time. ;

[0022] S3, in the equilibrium state on the membrane surface Based on the normal serviceability limit state, live load, snow load or water load are applied in combination to obtain the maximum vertical deformation of the membrane surface in each combination condition. and membrane surface loading ;

[0023] S4. Displace the center point of the drainage boundary downward along the plumb line. , and establish an arc formed by the first and last endpoints of the drainage boundary and the offset center point as the new drainage boundary;

[0024] S5. Order , repeat S2 to S3, and Establish a new membrane surface equilibrium , and calculate the new membrane surface deformation and membrane surface loading ,right Conduct contour analysis to determine whether there is an area with a contour closed loop;

[0025] S6. If there is a contour closed loop area on the membrane surface, , repeat S4 and S5; if The iteration get and ,and If there is no contour line closed loop in the area, execute step S7;

[0026] S7. Determine the angle between the line connecting the nearest points of adjacent contour lines and the horizontal plane Is it lower than the minimum drainage slope of the membrane material used? ;like , repeat S4, S5, S6; if , stop the iteration, at this time and This is the design boundary of the tensile membrane surface; based on this boundary, the equilibrium state of the tensile membrane structure is established. ;

[0027] S8, what S7 got Perform calculations based on the ultimate bearing capacity state and the normal use limit state to determine whether the calculation results meet the design specification requirements; if the calculation results do not meet the design specification requirements, return to S2 and adjust the membrane surface prestress according to the calculation results , and repeat S2 to S8. If the verification result meets the design specification requirements, the design is completed.

[0028] By adopting the above technical solution, the present invention has the following beneficial effects:

[0029] The present invention constructs a tensile membrane structure that does not rely on supporting components such as arches, cables, and struts to assist in constructing the membrane surface. A negative Gaussian surface is formed by designing a concave design on the membrane boundary, and a drainage path is formed along the concave direction. This ensures that the membrane surface has the stiffness and bearing capacity that meet the use requirements, while achieving organized drainage of the tensile membrane structure. At the same time, under the action of prestress, the membrane structure with the negative Gaussian surface has a structural stiffness that meets the use requirements. The corresponding design method can determine the size of the concave outer boundary of the tensile membrane based on the geometry of the roof structure with different shapes. The tensile membrane structure and its design method proposed by the present invention can avoid the influence and limitation of the traditional membrane structure shape and internal supporting components on the architectural effect, maximize the realization of the transparent and light architectural effect requirements, and avoid water accumulation in the membrane structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of a large-span roof tensile membrane structure and its supporting structure in the prior art.

[0032] Figure 2 Schematic diagram of the large-span roof tensile membrane structure (two non-drainage boundaries) provided by the present invention.

[0033] Figure 3 A schematic diagram of an embodiment of the large-span roof tensile membrane structure (two non-drainage boundaries) provided by the present invention.

[0034] Figure 4 Schematic diagram of the large-span roof tensile membrane structure (3 non-drainage boundaries) provided by the present invention.

[0035] Figure 5 A schematic diagram of an embodiment of the large-span roof tensile membrane structure (three non-drainage boundaries) provided by the present invention.

[0036] Figure 6 Schematic diagram of the large-span roof tensile membrane structure (4 non-drainage boundaries) provided by the present invention.

[0037] Figure 7 A schematic diagram of an embodiment of the large-span roof tensile membrane structure (4 non-drainage boundaries) provided by the present invention.

[0038] Figure 8 Schematic diagram of the U-shaped connection node of the large-span roof tensile membrane structure provided by the present invention.

[0039] Fig. 9 Schematic diagram of the anti-slip connection node of the large-span roof tension membrane structure provided by the present invention.

[0040] Fig.10 A schematic diagram of a U-shaped connection node and a concave arched boundary on the drainage boundary of a large-span roof tensile membrane structure provided by the present invention.

[0041] Fig.11 The present invention provides a flow chart of the long-span roof tensioned membrane structure design method.

[0042] Icons: 1- tensile membrane supporting arch; 2- tensile membrane boundary; 3- negative Gaussian curvature tensile membrane; 4- non-drainage boundary; 5- drainage boundary; 6- tensile membrane surface; 7- U-type connection node; 8- anti-slip connection node; 9- drainage trough; 10- rainwater gutter. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0045] Combination Figure 1 As shown, the long-span roof tensile membrane structure in the prior art is mainly composed of a tensile membrane supporting arch 1, a tensile membrane boundary 2 and a negative Gaussian curvature tensile membrane 3; these shapes are assisted by supporting components such as arches, cables, and struts inside the membrane. However, with the development of architectural technology, the common shapes of tensile membrane structural units and the components supporting their shapes can no longer meet the architects' pursuit of architectural shapes, especially the shapes and effects of long-span roofs.

[0046] Combination Figure 2-10 As shown, the present invention provides a large-span roof tensile membrane structure, including: no less than 2 non-drainage boundaries 4 and 1 drainage boundary 5; wherein:

[0047] The tensile membrane is stretched between the non-drainage boundary 4 and the drainage boundary 5;

[0048] The non-drainage boundaries 4 are located at the same elevation, or at different elevations;

[0049] The drainage boundary 5 is in a concave arch shape.

[0050] In the present application, the arch can be a circular arc, a parabola, an ellipse or a Nurbs curve. There is only one drainage point on the concave arch (composed of the drainage trough 9 and the rainwater bucket 10), and its elevation is at the lowest point of the entire tensile membrane surface.

[0051] In the present application, the tensile membrane structure is connected to the non-drainage boundary and the drainage boundary through two types of membrane surface nodes. The membrane surface nodes include U-shaped connection nodes 7 and anti-slip connection nodes 8;

[0052] The U-shaped connection node 7 provides tension constraints in a direction perpendicular to the boundary for the tension membrane surface 6;

[0053] The anti-slip connection node 8 provides the tensile membrane surface 6 with a tensile constraint in a direction perpendicular to the boundary, and also provides a sliding constraint parallel to the boundary direction; the U-shaped connection node and the anti-slip connection node are arranged according to the force requirements of the tensile membrane structure.

[0054] In this application, the angle between the line connecting the nearest points of adjacent contour lines of the tensile membrane structure and the horizontal plane is not less than the minimum drainage slope of the membrane material used. .

[0055] Combination Fig.11 As shown, the present invention provides a design method for a large-span roof tensile membrane structure, comprising the following steps:

[0056] S1. Determine all non-drainage boundaries and drainage boundaries according to the building shape. The non-drainage boundaries are recorded as , is the number of boundaries; the drainage boundary is recorded as , is the number of iterations;

[0057] S2, non-drained boundary and drainage boundaries Construct a zero-state model of the tensile membrane based on the preset membrane surface prestress The shape analysis is performed with the deadweight of the membrane structure to calculate the equilibrium state of the membrane surface at this time. ;

[0058] S3, in the equilibrium state on the membrane surface Based on the normal serviceability limit state, live load, snow load or water load are applied in combination to obtain the maximum vertical deformation of the membrane surface in each combination condition. and membrane surface loading ;

[0059] S4. Displace the center point of the drainage boundary downward along the plumb line. , and establish an arc formed by the first and last endpoints of the drainage boundary and the offset center point as the new drainage boundary;

[0060] S5. Order , repeat S2 to S3, and Establish a new membrane surface equilibrium , and calculate the new membrane surface deformation and membrane surface loading ,right Conduct contour analysis to determine whether there is an area with a contour closed loop;

[0061] S6. If there is a contour closed loop area on the membrane surface, , repeat S4 and S5; if The iteration get and ,and If there is no contour line closed loop in the area, execute step S7;

[0062] S7. Determine the angle between the line connecting the nearest points of adjacent contour lines and the horizontal plane Is it lower than the minimum drainage slope of the membrane material used? ;like , repeat S4, S5, S6; if , stop the iteration, at this time and This is the design boundary of the tensile membrane surface; based on this boundary, the equilibrium state of the tensile membrane structure is established. ;

[0063] S8, what S7 got Perform calculations based on the ultimate bearing capacity state and the normal use limit state to determine whether the calculation results meet the design specification requirements; if the calculation results do not meet the design specification requirements, return to S2 and adjust the membrane surface prestress according to the calculation results , and repeat S2 to S8. If the verification result meets the design specification requirements, the design is completed.

[0064] In summary, the present invention has greater adaptability than traditional tensile membrane structures in realizing architectural shapes, avoiding the influence and limitations of traditional membrane structure shapes and internal supporting components on architectural effects, and maximizing the realization of transparent and light architectural effect requirements.

[0065] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, 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 large-span roof tensile membrane structure, characterized in that: include: No less than 2 non-drainage boundaries and 1 drainage boundary; A tensile membrane is stretched between the non-drainage boundary and the drainage boundary; The non-drainage boundaries are located at the same elevation, or at different elevations; The drainage boundary is in a concave arch shape.

2. The long-span roof tensile membrane structure according to claim 1 is characterized in that: The arch is a circular arc, a parabola, an ellipse or a Nurbs curve.

3. The long-span roof tensile membrane structure according to claim 1 is characterized in that: There is only one drainage point on the concave arch, and its elevation is at the lowest point of the entire tensile membrane surface.

4. The long-span roof tensile membrane structure according to claim 1 is characterized in that: The tensile membrane structure is connected to the non-drainage boundary and the drainage boundary through two types of membrane surface nodes.

5. The long-span roof tensile membrane structure according to claim 4 is characterized in that: The membrane surface nodes include U-shaped connection nodes and anti-slip connection nodes; wherein, The U-shaped connection node provides a tension constraint in a direction perpendicular to the boundary for the tensioned membrane surface; The anti-slip connection node provides the tensile membrane surface with a tensile constraint in a direction perpendicular to the boundary, and also provides a sliding constraint parallel to the boundary direction; The U-shaped connection nodes and the anti-slip connection nodes are arranged according to the force requirements of the tensile membrane structure.

6. The long-span roof tensile membrane structure according to claim 1 is characterized in that: The angle between the line connecting the nearest points of the adjacent contour lines of the tensile membrane structure and the horizontal plane is not less than the minimum drainage slope of the membrane material used. .

7. A design method for a long-span roof tensile membrane structure according to any one of claims 1 to 6, characterized in that: The steps include: S1. Determine all non-drainage boundaries and drainage boundaries according to the building shape. The non-drainage boundaries are recorded as , is the number of boundaries; the drainage boundary is recorded as , is the number of iterations; S2, non-drained boundary and drainage boundaries Construct a zero-state model of the tensile membrane based on the preset membrane surface prestress The shape analysis is performed with the deadweight of the membrane structure to calculate the equilibrium state of the membrane surface at this time. ; S3, in the equilibrium state on the membrane surface Based on the normal serviceability limit state, live load, snow load or water load are applied in combination to obtain the maximum vertical deformation of the membrane surface in each combination condition. and membrane surface loading ; S4. Displace the center point of the drainage boundary downward along the plumb line. , and establish an arc formed by the first and last endpoints of the drainage boundary and the offset center point as the new drainage boundary; S5. Order , repeat S2 to S3, and Establish a new membrane surface equilibrium , and calculate the new membrane surface deformation and membrane surface loading ,right Conduct contour analysis to determine whether there is an area with a contour closed loop; S6. If there is a contour closed loop area on the membrane surface, , repeat S4 and S5; if The iteration get and ,and If there is no contour line closed loop in the area, execute step S7; S7. Determine the angle between the line connecting the nearest points of adjacent contour lines and the horizontal plane Is it lower than the minimum drainage slope of the membrane material used? ;like , repeat S4, S5, S6; if , stop iteration, at this time and This is the design boundary of the tensile membrane surface; based on this boundary, the equilibrium state of the tensile membrane structure is established. ; S8, what S7 got Perform calculations based on the ultimate bearing capacity state and the normal use limit state to determine whether the calculation results meet the design specification requirements; if the calculation results do not meet the design specification requirements, return to S2 and adjust the membrane surface prestress according to the calculation results , and repeat S2~S8; if the verification results meet the design specification requirements, the design is completed.

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