Alternate composite cable dome structure and implementation method thereof
阅读说明：本技术 一种交替复合式索穹顶结构及其实施方法 (Alternate composite cable dome structure and implementation method thereof ) 是由 张爱林 张艳霞 朱莉娜 文闻 林海鹏 于 2019-12-06 设计创作，主要内容包括：本发明实施例提供了一种交替复合式索穹顶结构及其实施方法,包括：支撑组件、索组件和外压刚性环梁；支撑组件包括：中心撑杆、等高双撑杆、单撑杆、不等高双撑杆和水平压杆,所述等高双撑杆、单撑杆和不等高双撑杆在每一榀由索穹顶中心向索穹顶最外圈依次布置；索组件包括：脊索组件、环索组件、斜索组件和外拉斜索组件,斜索组件在每一榀由索穹顶中心向索穹顶最外圈单依次布置。本发明实施例提供了一种交替复合式索穹顶结构,不等高双撑杆与水平压杆首尾相接形成闭合撑杆环,撑杆与脊索、斜索形成四面体结构,提高了该索穹顶结构几何稳定性,构件数少易于施工安装和张拉成形,减少施工成本,综合经济效益良好。(The embodiment of the invention provides an alternate composite cable dome structure and an implementation method thereof, wherein the alternate composite cable dome structure comprises the following steps: the supporting assembly, the cable assembly and the external pressure rigid ring beam; the support assembly includes: the cable dome comprises a central stay bar, equal-height double stay bars, a single stay bar, unequal-height double stay bars and a horizontal compression bar, wherein the equal-height double stay bars, the single stay bars and the unequal-height double stay bars are sequentially arranged from the center of the cable dome to the outermost ring of the cable dome in each truss; the cable assembly includes: the device comprises a ridge cable assembly, a ring cable assembly, a stay cable assembly and an outer stay cable assembly, wherein the stay cable assemblies are sequentially arranged from the center of the cable dome to the outermost ring of the cable dome in each roof truss. The embodiment of the invention provides an alternate composite cable dome structure, wherein unequal-height double support rods and horizontal compression rods are connected end to form a closed support rod ring, and the support rods, ridge cables and inclined cables form a tetrahedral structure, so that the geometric stability of the cable dome structure is improved, the number of components is small, the construction and installation and stretch forming are easy, the construction cost is reduced, and the comprehensive economic benefit is good.)
1. An alternating composite cable dome structure, comprising: the supporting assembly, the cable assembly and the external pressure rigid ring beam;
the support assembly includes: the cable dome comprises a central stay bar, equal-height double stay bars, a single stay bar, unequal-height double stay bars and a horizontal compression bar, wherein the equal-height double stay bars, the single stay bars and the unequal-height double stay bars are sequentially arranged from the center of the cable dome to the outermost ring of the cable dome in each truss;
the cable assembly includes: the device comprises a ridge cable assembly, a ring cable assembly, an oblique cable assembly and an outer stay cable assembly, wherein the oblique cable assemblies are sequentially arranged from the center of a cable dome to the outermost ring of the cable dome in each roof truss;
the annular cable assembly comprises a first annular cable, a second annular cable and a third annular cable, the centers of the first annular cable, the second annular cable and the third annular cable are positioned on the axis of the external pressure rigid annular beam, the first annular cable is positioned below the central support rod, the second annular cable is positioned below the first annular cable, and the third annular cable is positioned below the second annular cable;
the central support rod is vertically arranged above the axis of the external pressure rigid ring beam, the upper end of the central support rod is connected with the ridge cable assembly, and the lower end of the central support rod is connected with the inclined cable assembly;
the upper end points of the equal-height double supporting rods, the single supporting rods and the unequal-height double supporting rods are connected with the ridge cable assembly and the inclined cable assembly;
the lower end points of the equal-height double supporting rods, the single supporting rods and the unequal-height double supporting rods are connected with the inclined cable assembly and the annular cable assembly;
the adjacent equal-height double supporting rods are connected at the upper end points of the annular ring to form a closed supporting rod ring;
the unequal-height double support rods are connected with the horizontal pressure rod end to form a closed support rod ring;
and the external pressure rigid ring beam is connected with the outermost circle of inclined cable assembly and the outermost circle of ridge cable assembly.
2. The structure of claim 1, wherein the spinal chord assembly comprises: the first ridge cable is connected with the first end of the first cable;
the oblique cable assembly comprises an inner oblique cable, a first single oblique cable, a double oblique cable and a second single oblique cable, wherein the inner oblique cable, the first single oblique cable, the double oblique cable and the second single oblique cable are sequentially arranged from the center of the dome to the outside of the rigid ring beam;
the outer stay assembly includes: an inclined cable is pulled outwards;
the upper end point of the external stay cable is connected with the upper end point of the third ridge cable and the upper end points of the unequal-height double stay bars, and the lower end point of the external stay cable is connected with the lower end points of the second ring cable, the double stay cables and the single stay bar.
3. The structure of claim 2, wherein the upper ends of the inner ridge cables intersect at a point and are radial, the upper ends of the inner ridge cables are further connected with the upper end of the central stay bar, and the lower ends of the inner ridge cables are connected with the upper end of the first ridge cable;
the lower end point of the first ridge cable is connected with the upper end point of the second ridge cable;
the lower end point of the second ridge cable is connected with the upper end point of the third ridge cable;
and the lower end point of the third ridge cable is connected with the external pressure rigid ring beam.
4. The structure of claim 3, wherein the first looped cable, the second looped cable, and the third looped cable are each a polygon;
each vertex of the first annular cable is connected with the lower end point of the equal-height double stay bar and the lower end point of the first single inclined cable;
each vertex of the second annular cable is connected with the lower end point of the single stay bar, the lower end point of the outer stay rope and the lower end point of the double stay ropes;
and each vertex of the third ring cable is connected with the lower end point of the double support rods with different heights and the lower end point of the second single oblique cable.
5. The structure as claimed in claim 4, wherein the lower end points of the inner stay cables intersect and are radial, the lower end points of the inner stay cables are also connected with the lower end point of the central stay rod, and the upper end points of the inner stay cables are connected with the upper end points of the equal-height double stay rods, the lower end point of the inner ridge cable and the upper end point of the first ridge cable;
the lower end point of the first single inclined cable is connected with the top point of the first ring cable and the lower end point of the equal-height double stay bar, and the upper end point of the first single inclined cable is connected with the upper end point of the single stay bar, the lower end point of the first ridge cable and the upper end point of the second ridge cable;
the lower end points of the double inclined cables are connected with the top point of the second annular cable and the lower end point of the single stay bar, and the upper end points of the double inclined cables are connected with the upper end points of the unequal-height double stay bars and the lower end point of the second ridge cable;
the lower end point of the second single oblique cable is connected with the top point of the third ring cable and the lower end point of the unequal-height double supporting rods, and the upper end point of the second single oblique cable is connected with the lower end points of the external pressure rigid ring beam and the third ridge cable.
6. The structure of claim 1, wherein the cable dome structure has a plan projection in the form of a standard circle.
7. The structure of claim 2, wherein the horizontal projection of the double strut is coincident with the first eye.
8. A method of implementing the alternating composite cable dome structure of any one of claims 1-7, comprising the steps of:
s1, determining the span and the sagittal ratio of the cable dome structure, and determining the connection mode between the outermost ring node of the cable dome structure and the external pressure rigid ring beam, wherein the connection mode comprises the following steps:
selecting a cable dome structural span according to design requirements and actual conditions, preliminarily selecting the rise of a cable dome according to related specifications of cables, and adopting hinged connection at a connection place of an external pressure rigid ring beam and the cable dome;
s2, calculating the internal force of the cable dome structure by using a node balance method and a displacement method, wherein the method comprises the following steps:
the cable dome structure is symmetrical along the central line of each truss and is also symmetrical along the straight line where the inner ridge cable of the innermost ring is located, and the internal force of the central stay rod is assumed to be V0The number of unknown force cables connected with the upper end and the lower end of the central stay bar is more than 2, the internal force of each cable is calculated by using a node balance method, the internal force of the equal-height double stay bars and the inclined cables connected with the first ring cable can be calculated in the same way, and the internal force of the single stay bar and the ridge cable can be calculated in the same way;
regarding the inclined cable, the annular cable and the single stay bar connected with the second annular cable as a unit and intersecting the unit at one point, and applying the internal force of the single stay bar on a node of the unit as a known external force, assuming that the remote connecting node with the inclined cable and the annular cable cannot generate displacement due to the action of the external force, namely, the remote node is regarded as hinged; the unit rigidity of the inclined cable and the ring cable is known, and the unit rigidity is obtained according to the unit rigidity of the inclined cable, the ring cable, the ridge cable and the single support rod connected with the unit; the internal force of the single stay bar connected with the second ring cable is known, and when a known force acts on a unit node with known unit rigidity, the displacement of the unit under the action of external force can be obtained; the displacement of the unit node is also the displacement of the connecting end points of the oblique cable and the circular cable; when the displacement and the unit rigidity are known, the internal force of the ring cable and the oblique cable can be obtained;
in the same way, the internal force of the inclined cable, the annular cable, the unequal-height double supporting rods and the ridge cable connected with the third annular cable can be obtained;
s3, preliminarily determining the size of the component, and the size of the prestress on the looped cable:
amplifying the internal force of each cable rod calculated in the S2 to enable the structure to bear the load specified by the specification and the deformation requirement specified by the specification, then applying the internal force to the cable dome structure, controlling the displacement of the cable dome structure after deformation within the range defined by the specification, and selecting the cross section sizes of the cable and the rod according to the internal force of the cable rod after deformation as a reference basis;
s4, carrying out ultimate bearing capacity, ultimate state analysis of normal use and other necessary analysis on the structure;
the cable dome structure has enough rigidity and bearing capacity after S1-S3, constant load, live load, snow load and wind load are applied to the cable dome structure according to the building structure load specification, the loads are combined according to the specification requirement and are applied to the cable dome structure, node displacement and the changed rise-span ratio are controlled, if the relevant specification is not met, the initial prestress of a cable assembly is increased, or the height of a strut assembly is adjusted, and the iteration is repeated until the specification requirement is met;
s5, adjusting and optimizing parameters, meeting the specification requirement:
and optimizing the structure by taking the section diameter of the strut assembly or the total weight of the cable dome structure as a control parameter.
Technical Field
The invention relates to the technical field of building structures, in particular to an alternate composite cable dome structure and an implementation method thereof.
Background
The cable dome structure is a structure which is always in a continuous tension state and comprises discontinuous compression bars; the cable dome structure also belongs to a self-balancing self-supporting system, and the structure consists of a ridge cable, a ring cable and a pressure lever, wherein the ridge cable, the ring cable and the pressure lever interact with each other to form a structural system, and the structure is continuously self-balancing in the forming process. The structure has no natural stiffness before the cable is not pre-stressed, and stiffness is produced after pre-stressing. Meanwhile, a reasonable cable dome structure system has great influence on the rigidity and stability of the cable dome structure. At present, the cable dome structure existing at home and abroad has a single structural form, and although the overall stability and rigidity are greatly improved compared with the traditional cable dome structure, more rod pieces are arranged at nodes, and the construction is complex. There is not a cable dome structure system which is suitable for large span, good in overall stability, high in lateral rigidity, uniform in structural arrangement and few in node rod pieces.
Disclosure of Invention
Embodiments of the present invention provide an alternating composite cable dome structure and method for implementing the same to overcome the deficiencies of the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme.
An alternating composite cable dome structure comprising: the supporting assembly, the cable assembly and the external pressure rigid ring beam;
the support assembly includes: the cable dome comprises a central stay bar, equal-height double stay bars, a single stay bar, unequal-height double stay bars and a horizontal compression bar, wherein the equal-height double stay bars, the single stay bars and the unequal-height double stay bars are sequentially arranged from the center of the cable dome to the outermost ring of the cable dome in each truss;
the cable assembly includes: the device comprises a ridge cable assembly, a ring cable assembly, an oblique cable assembly and an outer stay cable assembly, wherein the oblique cable assemblies are sequentially arranged from the center of a cable dome to the outermost ring of the cable dome in each roof truss;
the annular cable assembly comprises a first annular cable, a second annular cable and a third annular cable, the centers of the first annular cable, the second annular cable and the third annular cable are positioned on the axis of the external pressure rigid annular beam, the first annular cable is positioned below the central support rod, the second annular cable is positioned below the first annular cable, and the third annular cable is positioned below the second annular cable;
the central support rod is vertically arranged above the axis of the external pressure rigid ring beam, the upper end of the central support rod is connected with the ridge cable assembly, and the lower end of the central support rod is connected with the inclined cable assembly;
the upper end points of the equal-height double supporting rods, the single supporting rods and the unequal-height double supporting rods are connected with the ridge cable assembly and the inclined cable assembly;
the lower end points of the equal-height double supporting rods, the single supporting rods and the unequal-height double supporting rods are connected with the inclined cable assembly and the annular cable assembly;
the adjacent equal-height double supporting rods are connected at the upper end points of the annular ring to form a closed supporting rod ring;
the unequal-height double support rods are connected with the horizontal pressure rod end to form a closed support rod ring;
and the external pressure rigid ring beam is connected with the outermost circle of inclined cable assembly and the outermost circle of ridge cable assembly.
Preferably, the spinal chord assembly comprises: the first ridge cable is connected with the first end of the first cable;
the oblique cable assembly comprises an inner oblique cable, a first single oblique cable, a double oblique cable and a second single oblique cable, wherein the inner oblique cable, the first single oblique cable, the double oblique cable and the second single oblique cable are sequentially arranged from the center of the dome to the outside of the rigid ring beam;
the outer stay assembly includes: an inclined cable is pulled outwards;
the upper end point of the external stay cable is connected with the upper end point of the third ridge cable and the upper end points of the unequal-height double stay bars, and the lower end point of the external stay cable is connected with the lower end points of the second ring cable, the double stay cables and the single stay bar.
Preferably, the upper end points of the inner ridge cables intersect at one point and are radial, the upper end points of the inner ridge cables are also connected with the upper end points of the central support rods, and the lower end points of the inner ridge cables are connected with the upper end points of the first ridge cables;
the lower end point of the first ridge cable is connected with the upper end point of the second ridge cable;
the lower end point of the second ridge cable is connected with the upper end point of the third ridge cable;
and the lower end point of the third ridge cable is connected with the external pressure rigid ring beam.
Preferably, the first looped cable, the second looped cable and the third looped cable are all polygons;
each vertex of the first annular cable is connected with the lower end point of the equal-height double stay bar and the lower end point of the first single inclined cable;
each vertex of the second annular cable is connected with the lower end point of the single stay bar, the lower end point of the outer stay rope and the lower end point of the double stay ropes;
and each vertex of the third ring cable is connected with the lower end point of the double support rods with different heights and the lower end point of the second single oblique cable.
Preferably, the lower end points of the inner stay cables are intersected and radial, the lower end points of the inner stay cables are also connected with the lower end point of the central stay rod, and the upper end points of the inner stay cables are connected with the upper end points of the equal-height double stay rods, the lower end point of the inner ridge cable and the upper end point of the first ridge cable;
the lower end point of the first single inclined cable is connected with the top point of the first ring cable and the lower end point of the equal-height double stay bar, and the upper end point of the first single inclined cable is connected with the upper end point of the single stay bar, the lower end point of the first ridge cable and the upper end point of the second ridge cable;
the lower end points of the double inclined cables are connected with the top point of the second annular cable and the lower end point of the single stay bar, and the upper end points of the double inclined cables are connected with the upper end points of the unequal-height double stay bars and the lower end point of the second ridge cable;
the lower end point of the second single oblique cable is connected with the top point of the third ring cable and the lower end point of the unequal-height double supporting rods, and the upper end point of the second single oblique cable is connected with the lower end points of the external pressure rigid ring beam and the third ridge cable.
Preferably, the cable dome structure has a plane projection in a standard circle.
Preferably, the horizontal projection of the equal-height double supporting rod is coincident with the first looped cable.
An implementation method of an alternating composite cable dome structure comprises the following steps:
s1, determining the span and the sagittal ratio of the cable dome structure, and determining the connection mode between the outermost ring node of the cable dome structure and the external pressure rigid ring beam, wherein the connection mode comprises the following steps:
selecting a cable dome structural span according to design requirements and actual conditions, preliminarily selecting the rise of a cable dome according to related specifications of cables, and adopting hinged connection at a connection place of an external pressure rigid ring beam and the cable dome;
s2, calculating the internal force of the cable dome structure by using a node balance method and a displacement method, wherein the method comprises the following steps:
the cable dome structure is symmetrical along the central line of each truss and is also symmetrical along the straight line where the inner ridge cable of the innermost ring is located, and the internal force of the central stay rod is assumed to be V0The number of unknown force cables connected with the upper end and the lower end of the central stay bar is more than 2, the internal force of each cable is calculated by using a node balance method, the internal force of the equal-height double stay bars and the inclined cables connected with the first ring cable can be calculated in the same way, and the internal force of the single stay bar and the ridge cable can be calculated in the same way;
regarding the inclined cable, the annular cable and the single stay bar connected with the second annular cable as a unit and intersecting the unit at one point, and applying the internal force of the single stay bar on a node of the unit as a known external force, assuming that the remote connecting node with the inclined cable and the annular cable cannot generate displacement due to the action of the external force, namely, the remote node is regarded as hinged; the unit rigidity of the inclined cable and the ring cable is known, and the unit rigidity is obtained according to the unit rigidity of the inclined cable, the ring cable, the ridge cable and the single support rod connected with the unit; the internal force of the single stay bar connected with the second ring cable is known, and when a known force acts on a unit node with known unit rigidity, the displacement of the unit under the action of external force can be obtained; the displacement of the unit node is also the displacement of the connecting end points of the oblique cable and the circular cable; when the displacement and the unit rigidity are known, the internal force of the ring cable and the oblique cable can be obtained;
in the same way, the internal force of the inclined cable, the annular cable, the unequal-height double supporting rods and the ridge cable connected with the third annular cable can be obtained;
s3, preliminarily determining the size of the component, and the size of the prestress on the looped cable:
amplifying the internal force of each cable rod calculated in the S2 to enable the structure to bear the load specified by the specification and the deformation requirement specified by the specification, then applying the internal force to the cable dome structure, controlling the displacement of the cable dome structure after deformation within the range defined by the specification, and selecting the cross section sizes of the cable and the rod according to the internal force of the cable rod after deformation as a reference basis;
s4, carrying out ultimate bearing capacity, ultimate state analysis of normal use and other necessary analysis on the structure;
the cable dome structure has enough rigidity and bearing capacity after S1-S3, constant load, live load, snow load and wind load are applied to the cable dome structure according to the building structure load specification, the loads are combined according to the specification requirement and are applied to the cable dome structure, node displacement and the changed rise-span ratio are controlled, if the relevant specification is not met, the initial prestress of a cable assembly is increased, or the height of a strut assembly is adjusted, and the iteration is repeated until the specification requirement is met;
s5, adjusting and optimizing parameters, meeting the specification requirement:
and optimizing the structure by taking the section diameter of the strut assembly or the total weight of the cable dome structure as a control parameter.
According to the technical scheme provided by the embodiment of the invention, the embodiment of the invention provides the alternating composite cable dome structure and the implementation method thereof, the cable dome structure can effectively resist non-uniform load, and the deformation of the upper layer cable after being stressed is restrained due to the existence of the cable and the horizontal compression bar in the upper layer structure, so that the structural integrity is better. The support rods, the ridge cables and the oblique cables form a tetrahedral structure, so that the geometric stability of the cable dome structure is improved. In addition, the number of node members on the whole structure is small, construction, installation and stretch-draw forming are easy, construction cost is reduced, and comprehensive economic benefits are good.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a three-dimensional view of an alternating composite cable dome structure according to an embodiment of the present invention;
FIG. 2 is a schematic plan view of an alternate composite cable dome initial geometry according to an embodiment of the present invention;
FIG. 3 is a simplified diagram of an alternative hybrid cable dome initial geometry calculation according to an embodiment of the present invention;
FIG. 4 is a three-dimensional view of an alternate composite cable dome geometry for a roof truss structure according to an embodiment of the present invention;
fig. 5 is a plan view of an alternate composite cable dome geometry one-pin structure according to an embodiment of the present invention.
Reference numerals
11. A center stay; 12. equal-height double support rods; 13. a single stay bar; 14. double support rods with different heights; 21. an inner oblique cable; 22. a first single oblique cable; 23. a double oblique cable; 24. a second single oblique cable; 31. an inner spinal cord; 32. a first spinal cord; 33. a second spinal cord; 34. a third spinal cord; 41. a first looped cable; 42. a second looped cable; 43. a third looped cable; 5. an inclined cable is pulled outwards; 6. a horizontal compression bar; 7. and (4) externally pressing the rigid ring beam.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
For the convenience of understanding the embodiments of the present invention, the following description will be further explained by taking several specific embodiments as examples in conjunction with the drawings, and the embodiments are not to be construed as limiting the embodiments of the present invention.
An embodiment of the present invention provides an alternating composite cable dome structure, as shown in fig. 1 to 5, a cable dome structure has a plane projection in a standard circle, and includes: a support assembly, a cable assembly and an external pressure rigid ring beam.
The support assembly includes: the cable dome comprises a
The cable assembly includes: a spinal cable assembly, a ring cable assembly, a stay cable assembly, and an outer stay cable assembly. Wherein, the spinal chord subassembly includes: the ridge cable assembly comprises
The
The upper end points of the equal-height
The upper end point of the
One upper end point of the unequal-height
The lower end point of the
The upper end point of the
The
The lower end points of the 6 inner oblique cables 21 are intersected and radial, the lower end points of the inner oblique cables 21 are connected with the lower end point of the central stay 11, and the upper end points of the inner oblique cables 21 are connected with the upper end points of the equal-height double stay 12, the lower end point of the inner ridge cable 31 and the upper end point of the first ridge cable 32; the lower end point of the first single inclined cable 22 is connected with the top point of the first ring cable 41 and the lower end point of the equal-height double stay 12, and the upper end point thereof is connected with the upper end point of the single stay 13, the lower end point of the first ridge cable 32 and the upper end point of the second ridge cable 33; the lower end point of the double inclined cable 23 is connected with the top point of the second ring cable 42 and the lower end point of the single stay bar 13, and the upper end point thereof is connected with the upper end point of the unequal-height double stay bar 14 and the lower end point of the second ridge cable 33; the lower end point of the second single oblique cable 24 is connected with the top point of the third ring cable 43 and the lower end point of the unequal-height double supporting rods 14, and the upper end point thereof is connected with the lower end points of the external pressure rigid ring beam 7 and the third ridge cable 34.
The invention also provides an implementation method of the alternating composite cable dome structure, which comprises the following steps:
s1, firstly determining the span and the sagitta ratio of the cable dome structure, and determining the connection mode between the outermost ring node of the cable dome structure and the external pressure rigid ring beam;
selecting proper cable dome span according to design requirements and practical conditions, and preliminarily selecting the rise of the cable dome according to relevant specifications of the cable. Since the cable dome structure is under considerable tension against the peripheral rigid ring beam after prestressing, a relatively large cross-section has to be chosen. The external pressure rigid ring beam is hinged with the cable dome, so that the cable dome structure is favorably deformed after prestress is applied.
S2, calculating the internal force of the structure by using a node balance method and a displacement method;
the cable dome structure is symmetrical along the central line of each roof truss and is also symmetrical along the straight line where the innermost inner ridge cable is located, so that the cable dome structure can be simplified, as shown in fig. 3, and the subsequent theoretical analysis is facilitated. Assuming that the internal force of the central stay bar is V0, the number of unknown force cables connected with the upper end and the lower end of the central stay bar is more than 2, at the moment, the internal force of each cable can be obtained by using a node balance method, the internal force of the equal-height double stay bars and the inclined cables connected with the first ring cable can be obtained in the same way, and the internal force of the single stay bar and the ridge cable can be obtained in the same way. Because the oblique cables connected with the second ring cables are connected with the upper end points of the unequal-height double supporting rods, the oblique cables are not symmetrical at the moment, so that the unknown force of the rod pieces connected with the second ring cables is 3, the node balance method cannot be used for solving the unknown force, and a displacement method is introduced at the moment. The inclined cable, the ring cable and the single stay connected with the second ring cable are regarded as a research unit and are intersected at one point, and the internal force of the single stay is applied to the node of the unit as a known external force. Because the cable dome has enough rigidity after the prestress is applied, the connection node at the far end of the oblique cable and the circular cable can be assumed not to be displaced due to the action of external force, namely the far end node is regarded as hinged. If the unit rigidity of the oblique cable and the annular cable is known, the unit rigidity can be obtained according to the unit rigidity of each cable rod. Since the internal force of the struts connected to the second cable loop is known, the displacement of the unit under the action of an external force can be determined when a known force acts on the node of the unit with a known unit stiffness. When the cables in the unit intersect at one point, the displacement of the unit node is also the displacement of the connecting end point of the oblique cable and the circular cable. When the displacement and the unit rigidity are known, the internal force of the ring cable and the oblique cable can be obtained. And the internal force of the inclined cable, the annular cable, the unequal-height double-support rods and the ridge cable connected with the third annular cable can be obtained in the same way.
S3, preliminarily determining the size of the component and the size of the prestress on the looped cable;
amplifying the internal force of each cable rod calculated in the step S2 to enable the structure to bear the load specified by the specification and the deformation requirement specified by the specification, then applying the internal force to the cable dome structure, controlling the displacement of the cable dome structure after deformation within the range defined by the specification, and selecting the appropriate cross-sectional dimension of the cable rod and the cable rod according to the internal force of the cable rod after deformation as a reference basis. Note that the initial pre-stress of the cable assembly does not exceed 0.45 times the ultimate breaking force, and the axial compression ratio of the strut assembly is controlled within a reasonable range.
S4, carrying out ultimate bearing capacity, ultimate state analysis of normal use and other necessary analysis on the structure;
the cable dome structure has enough rigidity and bearing capacity after the steps of S1, S2 and S3, and is subjected to constant load, live load, snow load, wind load and the like according to the building structure load specification, and the loads are subjected to load combination according to the specification requirement and are applied to the cable dome structure. And controlling node displacement, the vector-span ratio after deformation and the like, if the node displacement and the vector-span ratio do not meet relevant specifications, increasing the initial prestress of the cable assembly, or adjusting the height of the strut assembly, and repeating iteration until the requirements of the specifications are met.
S5, adjusting and optimizing the parameters while meeting the specification requirements.
In order to make the economic benefit of the cable dome structure higher, the structure can be optimized by taking the section diameter of the strut assembly or the total weight of the structure as a control parameter on the premise of not influencing the bearing capacity of the cable dome.
In summary, the embodiments of the present invention provide an alternating composite cable dome structure, wherein the cable dome structure has a plane projection in a standard circle, the supporting components are compression rods, the horizontal compression rods are compression rods, and the other components are tension cables. The double support rods with the same height as the innermost ring of the cable dome are closed in the annular direction, so that the inner ring of the cable dome has enough bearing capacity, and the inner ring is prevented from collapsing under the action of load. The cable and the steel pipe are arranged on the upper layer member of the cable dome structure at the same time, the cable and the steel pipe are not arranged on other cable dome structures, the horizontal compression rods and the double support rods with different heights form a closed support rod circle together, compared with the traditional cable dome structure, the cable dome structure is continuous in the annular direction, so that the capacity of resisting non-uniform load of the cable dome structure is further improved, and meanwhile, the deformation of the upper layer cable after being stressed is restrained due to the horizontal compression rods arranged between the upper layer cables, so that the structural integrity is better. The support rods, the ridge cables and the oblique cables form a tetrahedral structure, so that the geometric stability of the cable dome structure is improved. The number of the equal-height double supporting rods and the first single oblique cables connected with one node of the first ring cable is only three, the number of the unequal-height double supporting rods and the second single oblique cables connected with one node of the third ring cable is also only three, the number of components is small, construction, installation and stretch forming are easy, construction cost is reduced, and comprehensive economic benefits are good. The invention also provides an implementation method of the alternating composite cable dome structure, and the method is simple and easy to implement and is used for analyzing the internal force of the structure by using a node balance method and a displacement method.
Those of ordinary skill in the art will understand that: the figures are merely schematic representations of one embodiment, and the blocks or flow diagrams in the figures are not necessarily required to practice the present invention.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for apparatus or system embodiments, since they are substantially similar to method embodiments, they are described in relative terms, as long as they are described in partial descriptions of method embodiments. The above-described embodiments of the apparatus and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种大空间阻燃吸音吊顶结构