A large-span roof tensile membrane structure and a design method thereof

Abstract

The present application relates to the technical field of structural design of construction engineering, and especially relates to a large-span roof tensile membrane structure and a design method thereof; the large-span roof tensile membrane structure comprises: no less than two non-draining boundaries and one draining boundary; the tensile membrane is tensiled between the non-draining boundaries and the draining boundary; the non-draining boundaries are located at the same elevation or different elevations; and the draining boundary is in a concave arch shape. The present application constructs a tensile membrane structure which does not rely on arches, cables, struts and other supporting members, forms a negative Gaussian surface by concave design of the membrane boundary, forms a draining path along the concave direction, and realizes organized drainage of the tensile membrane structure. Meanwhile, under the action of prestress, the membrane structure of the negative Gaussian surface has a structural rigidity which meets the use requirements. The corresponding design method can determine the size of the concave of the outer boundary of the tensile membrane based on the geometry of the roof structure of different shapes. The tensile membrane structure and the design method thereof proposed by the present application can avoid the influence and limitation of the traditional membrane structure modeling and internal supporting members on the architectural effect, maximize the realization of the demand for transparent and light architectural effect, and at the same time avoid water accumulation of the membrane structure.

Description

Technical Field

[0001] This invention relates to the field of structural design technology in building engineering, and in particular to a large-span tensile membrane roof structure and its design method. Background Technology

[0002] Compared to traditional structures, membrane structures offer advantages such as light weight, large span, convenient construction, good light transmission, and good self-cleaning properties. Furthermore, as flexible structures, their adaptability to deformation is far superior to rigid enclosure structures. Therefore, membrane structures are often the preferred roof cladding system for large-span cable-stayed 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 primarily that the material itself lacks rigidity and shape; prestressing is required to achieve the necessary structural rigidity and shape. Common tensile membrane structure unit shapes include hyperbolic paraboloid saddle shapes, conical umbrella shapes, or double umbrella shapes with negative Gaussian curvature. These shapes are formed with the assistance of supporting components such as arches, cables, and struts within the membrane. However, with the development of architectural technology, the common shapes of tensile membrane structure units and the supporting components can no longer meet architects' demands for architectural form, especially for large-span roofs.

[0003] Tensile membrane structures without internal support members offer greater adaptability in achieving architectural forms. Compared to rigid enclosure structures, they can significantly reduce roof weight, decrease the number of roof structural components, and improve the lightness and transparency of the building's roof. However, membrane structures without internal support members present the following problems: the membrane material can only withstand in-plane tension; loads perpendicular to the membrane surface are converted into in-plane tension through membrane deformation. Unlike traditional tensile membrane structures that rely on arches, struts, or cables to create hyperbolic paraboloids, saddle shapes, conical umbrella shapes, or other negative Gaussian curvature shapes to prevent water accumulation, membranes without internal support members have a smaller curvature. Under vertical loads, deformation easily forms concave pits, leading to water and snow accumulation. This creates a "water trap" effect, resulting in a vicious cycle of continuously increasing deformation and load, posing safety hazards and severely limiting the engineering applications of this type of tensile membrane structure.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art 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 objectives of the present invention is to provide a large-span tensile membrane roof structure; another objective of the present invention is to provide a design method for such a large-span tensile membrane roof structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A large-span tensile membrane roof structure includes: no less than two non-drainage boundaries and one drainage boundary;

[0008] The 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 a concave arch shape.

[0011] Furthermore, the arch can be 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 tensile constraint on the tension membrane surface in the direction perpendicular to the boundary;

[0016] The anti-slip connection node provides tensile constraints perpendicular to the boundary of the tension membrane surface, as well as sliding constraints parallel to the boundary direction.

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

[0018] Furthermore, 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. .

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

[0020] S1. Determine all non-drainage boundaries and drainage boundaries based on the building's design. Non-drainage boundaries are denoted as... , The number of boundaries; drainage boundaries are denoted as , This represents the number of iterations.

[0021] S2, with non-drainage boundary and drainage boundary Construct a zero-state model of the tensile membrane based on the preset membrane prestress. A form-finding analysis was performed using the membrane structure's self-weight to calculate the membrane surface equilibrium state at this point. ;

[0022] S3, in equilibrium state at 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 for each combined load condition. and membrane surface loading state ;

[0023] S4. Offset the center point of the drainage boundary downwards along the plumb line by the sag. And establish an arc formed by the beginning and end points of the drainage boundary and the offset center point as the new drainage boundary;

[0024] S5, Order Repeat S2 to S3, to and Establishing a new membrane equilibrium state And calculate the new membrane deformation. and membrane surface loading state ,right Perform contour analysis to determine if there are regions with closed contour loops;

[0025] S6. If there are regions with closed contour lines on the membrane surface, then make Repeat S4 and S5; if the first... The next iteration makes get and ,and If there is no closed contour line loop in the area, proceed to step S7 for judgment;

[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 steps S4, S5, and S6; if Stop iterating at this point. and This refers to the design boundary of the tensile membrane surface; the equilibrium state of the tensile membrane structure is established based on this boundary. ;

[0027] S8, obtained from S7 Perform ultimate limit state and serviceability limit state verifications to determine if the results meet design specifications. If the results do not meet design specifications, return to step S2 and adjust the membrane prestress according to the verification results. Then repeat steps S2 through S8. If the verification results meet the design specifications, the design is complete.

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

[0029] This invention constructs a tensile membrane structure that does not rely on arches, cables, struts, or other supporting components to construct the membrane surface shape. By designing a concave shape at the membrane boundary to form a negative Gaussian surface, a drainage path is created along the concave direction. This ensures the membrane surface possesses the required stiffness and load-bearing capacity while achieving organized drainage of the tensile membrane structure. Simultaneously, under prestressing, the negative Gaussian surface membrane structure exhibits the required structural stiffness. The corresponding design method can determine the dimensions of the concave outer boundary of the tensile membrane based on the geometry of roof structures with different shapes. The tensile membrane structure and its design method proposed in this invention avoid the influence and limitations of traditional membrane structure shapes and internal supporting components on architectural effects, maximizing the achievement of transparent and lightweight architectural effects while preventing water accumulation in the membrane structure. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

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

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

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

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

[0035] Figure 5 This is a schematic diagram of an embodiment of the large-span tensile membrane roof structure (3 non-drainage boundaries) provided by the present invention.

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

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

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

[0039] Figure 9 This is a schematic diagram of the anti-slip connection node of the large-span tensile membrane roof structure provided by the present invention.

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

[0041] Figure 11 A flowchart illustrating the design method for a large-span tensile membrane roof structure provided by this invention.

[0042] Icons: 1-Tension membrane support arch; 2-Tension membrane boundary; 3-Negative Gaussian curvature tension membrane; 4-Non-drainage boundary; 5-Drainage boundary; 6-Tension membrane surface; 7-U-shaped connection node; 8-Anti-slip connection node; 9-Drainage channel; 10-Rainwater hopper. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0044] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0045] Combination Figure 1 As shown, existing large-span tensile membrane structures mainly consist of tensile membrane support arches 1, tensile membrane boundaries 2, and negative Gaussian curvature tensile membranes 3; these shapes are shaped with the assistance of supporting components such as arches, cables, and struts inside the membrane. However, with the development of building technology, the common shapes of tensile membrane structure units and the components supporting their shapes can no longer meet architects' pursuit of architectural forms, especially the shapes and effects of large-span roofs.

[0046] Combination Figure 2-10 As shown, the present invention provides a large-span tensile membrane roof structure, comprising: at least two non-drainage boundaries 4 and one 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 boundary 4 is located at the same elevation or at different elevations;

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

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

[0051] In this application, the tensile membrane structure is connected to both the non-drained and drained boundaries via two types of membrane surface nodes. The membrane surface nodes include U-shaped connection nodes 7 and anti-slip connection nodes 8; wherein,

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

[0053] In addition to providing tensile constraints perpendicular to the boundary, the anti-slip connection node 8 also provides sliding constraints parallel to the boundary direction for the tensile membrane surface 6; the U-shaped connection node and the anti-slip connection node are arranged according to the stress 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 Figure 11 As shown, this invention provides a design method for a large-span tensile membrane roof structure, comprising the following steps:

[0056] S1. Determine all non-drainage boundaries and drainage boundaries based on the building's design. Non-drainage boundaries are denoted as... , The number of boundaries; drainage boundaries are denoted as , This represents the number of iterations.

[0057] S2, with non-drainage boundary and drainage boundary Construct a zero-state model of the tensile membrane based on the preset membrane prestress. A form-finding analysis was performed using the membrane structure's self-weight to calculate the membrane surface equilibrium state at this point. ;

[0058] S3, in equilibrium state at 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 for each combined load condition. and membrane surface loading state ;

[0059] S4. Offset the center point of the drainage boundary downwards along the plumb line by the sag. And establish an arc formed by the beginning and end points of the drainage boundary and the offset center point as the new drainage boundary;

[0060] S5, Order Repeat S2 to S3, to and Establishing a new membrane equilibrium state And calculate the new membrane deformation. and membrane surface loading state ,right Perform contour analysis to determine if there are regions with closed contour loops;

[0061] S6. If there are regions with closed contour lines on the membrane surface, then make Repeat S4 and S5; if the first... The next iteration makes get and ,and If there is no closed contour line loop in the area, proceed to step S7 for judgment;

[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 steps S4, S5, and S6; if Stop iterating at this point. and This refers to the design boundary of the tensile membrane surface; the equilibrium state of the tensile membrane structure is established based on this boundary. ;

[0063] S8, obtained from S7 Perform ultimate limit state and serviceability limit state verifications to determine if the results meet design specifications. If the results do not meet design specifications, return to step S2 and adjust the membrane prestress according to the verification results. Then repeat steps S2 through S8. If the verification results meet the design specifications, the design is complete.

[0064] In summary, this invention has greater adaptability in realizing architectural shapes compared to traditional tensile membrane structures, avoiding the influence and limitations of traditional membrane structure shapes and internal support components on architectural effects, and maximizing the realization of transparent and lightweight architectural effects.

[0065] 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 or all of the technical features therein. Such modifications or substitutions 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 design method of a long-span roof tensile membrane structure, characterized by, The large-span roof tensile membrane structure comprises: no less than two non-draining boundaries and one draining boundary; The tensile membrane is stretched between the non-draining boundaries and the draining boundary; The non-draining boundaries are located at the same level or at different levels; The draining boundary is in a concave arch shape; The design method comprises the following steps: S1, determine all non-draining boundaries and draining boundaries according to the building shape, the non-draining boundaries are denoted as , is the boundary number; the draining boundaries are denoted as , is the iteration number; S2, with non-draining boundary and draining boundary Constructing the zero state model of the tensile membrane, based on the preset membrane prestress and membrane structure self-weight to find shape analysis, the membrane surface balance state is calculated at this time ; S3, in the membrane surface equilibrium state On the basis of the normal use limit state combination, the maximum membrane surface vertical deformation of each combination working condition is obtained by applying the live load and the membrane surface load state ; S4, offsetting the center point of the drainage boundary downward along the plumb direction by the offset height and establishing a circular arc formed by the first and last end points of the drainage boundary and the offset center point as a new drainage boundary; S5, let , repeat S2 to S3 to and establish a new membrane surface equilibrium state , and calculate the new membrane surface deformation and membrane surface load state , contour analysis is carried out on to determine whether there is a contour closed loop region; S6, if there is a region on the film surface where the contour line closed loop exists, then make , repeat S4 and S5; if the first iteration makes get and , and there is no contour line closed loop region on the film surface, perform S7 step judgment; S7, judging the included angle between the line connecting the nearest points of adjacent contour lines and the horizontal plane whether lower than the minimum drainage slope of the used membrane material ; if , repeating S4, S5, S6; if , stopping iteration, at this time and are the design boundary of the tensile membrane surface; based on this boundary, the equilibrium state of the tensile membrane structure is established ; S8, judging whether the calculation result conforms to the design specification requirement based on the bearing capacity limit state calculation and the normal use limit state calculation; if the calculation result does not conform to the design specification requirement, returning to S2, adjusting the membrane surface prestress according to the calculation result , and repeating S2-S8; if the calculation result conforms to the design specification requirement, the design ends. S8, judging whether the calculation result conforms to the design specification requirement based on the bearing capacity limit state calculation and the normal use limit state calculation; if the calculation result does not conform to the design specification requirement, returning to S2, adjusting the membrane surface prestress according to the calculation result , and repeating S2-S8; if the calculation result conforms to the design specification requirement, the design ends.

2. The method of designing a long span roof tensile membrane structure according to claim 1, wherein, The arch shape is a circular arc, a parabola, an ellipse or a Nurbs curve.

3. The method of designing a long span roof tensile membrane structure according to claim 1, wherein, There is only one point of drainage on the concave arch shape, which is at the lowest point of the entire tensile membrane surface.

4. The method of designing a long span roof tensile membrane structure according to claim 1, wherein, The tensile membrane structure is connected to the non-draining boundaries and the draining boundary through two types of membrane surface nodes.

5. The method of designing a long-span roof tensile membrane structure according to claim 4, wherein, The membrane surface nodes comprise U-shaped connecting nodes and anti-sliding connecting nodes; wherein, The U-shaped connecting nodes provide tensile constraint in the vertical direction of the boundary for the tensile membrane surface; The anti-sliding connecting nodes provide tensile constraint in the vertical direction of the boundary and sliding constraint in the parallel direction of the boundary for the tensile membrane surface; The U-shaped connecting nodes and the anti-sliding connecting nodes are arranged according to the stress requirement of the tensile membrane structure.

6. The method of designing a long span roof tensile membrane structure according to claim 1, wherein, 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 .

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