WO1990010762A1

WO1990010762A1 - A space frame

Info

Publication number: WO1990010762A1
Application number: PCT/NO1990/000047
Authority: WO
Inventors: Tor Bøen URDAL
Original assignee: Ingeniørene Bonde & Co. A/S
Priority date: 1989-03-10
Filing date: 1990-03-09
Publication date: 1990-09-20
Also published as: NO891037D0; AU5176190A; NO891037L

Abstract

A space frame (1) which is constructed from tubular lower chords (8) and upper chords (5) in respective substantially parallel planes, and inclined diagonal members (3) which connect the upper and lower chords in respective nodal connection points (4, 6). Upper and lower chords (5, 8) and diagonal members (3) form respective intersecting truss modules (2) which extend at a predetermined mutual distance and form open fields or bays (10) between intersecting truss modules (2). The open fields (10) between the intersecting truss modules (2) may adopt a square, rectangular, or rhombic configuration.

Description

A space frame

The present invention relates to a space frame of tubular lower chords and upper chords extending in respective substantially parallel planes, and, relative to said planes, inclined diagonal members connecting said upper and lower chords in respective nodal connection points.

Space frames are generally being defined as large span lattice constructions distributing stress in at least two directions in plan for use in providing roof or floor structures for buildings where large unobstructed floor areas are desired.

It is previously known to erect space frames, e.g. roofs of buildings, by means of scaffolding, propping up or "lift slab procedures". Common practice was to assemble the space frame in-situ. By means of separate nodal connection points individual chords and diagonal members are screwed together so that the entire assembly is carried out at the construc¬ tion site.

With the present space frame a minimum of work is intended to be carried out at the construction site, i.e. that sub- assemblies of the final space frame are prefabricated in a workshop. Thus truss modules are prefabricated to a dimension which may be transported to the building site. Only the final assembly of truss modules into a final space frame is carried out at the construction site.

When larger parts or modules of the space frame can be constructed in a workshop the nodal connection points may be manufactured in a less expensive as well as a simplified manner in the form of welded connections. In joining individual truss modules at the construction site the number of connecting points will be at a minimum. This will permit rapid and simple erection of the space frame on the construc¬ tion site. Additionally, the truss modules can readily be hoisted in place by existing cranes without use of scaffold¬ ing and temporary supports.

This is achieved by a space frame of the above mentioned kind which is characterized^' by the fact that upper and lower chords and diagonal members form respective intersecting truss modules which extend at a predetermined mutual distance and form respective open fields or bays between intersecting truss modules.

By a selection of the distances between and the sizes of the diagonal members and chords the open fields between Intersecting truss modules may adopt a square, rectangular, or rhombic configuration.

The number of nodal connection points in the plane of upper chords is generally twice the number of junction points in the plane of the lower chords. The number of upper chords is generally twice the number of lower chords. Preferably, each truss module is connected to an adjacent module with two upper chord rods, one lower chord rod and four diagonal members at each intersecting module.

Each nodal connection point is suitably all-welded. The upper chord joints forming the connection between respective truss modules which are placed at a mutual distance, preferably, comprise a support plate and bolt and nut connections. The lower chord joints forming the connection between respective truss modules which are placed at a mutual distance, preferably comprise a splice plate and bolt and nut connections. The splice plates are to be welded to the respective chords. Other and further objects, features, and advantages will appear from the following description of an presently preferred embodiment of the invention, which is illustrative only without being limiting, and is given with reference to the accompanying drawings, in which

Figure 1 is a perspective view of the space frame according to the invention, Figure 2 shows the space frame according to Figure 1 in top view, Figure 3 shows a detail of the space frame according to Figure 2 , Figures 4A,4B show details of the space frame according to Figure 1 in side elevations, Figures 5A,5B,5C show an upper chord joint between respective truss modules in detail, and Figures 6A,6B show an all-welded nodal connection point, and a joint of lower chords between respective truss modules.

Figure 1 is a perspective view of a space frame 1 which is constructed of tubular lower chords 8 and upper chords 5 extending in respective parallel planes. Upper chords 5 and lower chords 8 are inter-connected by inclined diagonal members 3 in respective nodal connection points 4, 6. Any suitable material may be used, e.g. steel, aluminium, and various alloys thereof.

As clearly appearing in Figure 2 the space frame 1 is con¬ structed from truss modules 2 which intersect at straight angles in the shown embodiment. In the shown embodiment the truss modules 2 are disposed at a mutual distance of one module width. Thus square open fields or bays 10 are, formed between respective intersecting truss modules 2. Naturally, the distance between respective intersecting truss modules may be shorter or longer, or the truss modules 2 may be further spaced apart in one direction or mutually displaced or staggered to form rectangular or rhombic open fields 10 between intersecting truss modules 2. As shown in Figure 2, the number of nodal connection points 4 in the plane of upper chords 5 is twice the number of nodal connection points 6 in the plane of lower chords 8. Cor¬ respondingly, the number of upper chords 5 will be twice that of lower chords 8.

Figure 3 shows in more detail how two truss modules 2 are joined for constructing a complete space frame 1. Specially designed upper chord rods 18 and lower chord rods 17 are used. The joints 11 forming the connection between respective truss modules 2 are at each end provided with a support plate 13 and a bolt connection 14, which are shown in more detail in Figures 5A - 5C. The support plate 13 is welded perpendicularly to the end of upper chord rod 18 and has a semi-circular section, as will appear from Figure 5C. The section of support plate 13 has a curvature adapted to the curvature of upper chord 5 to form a stable abutment against the latter. The support plate 13 is secured to upper chord 5 by means of a bolt and nut connection 14, and/or is welded to the chord. The lower chords 8 are connected by means of lower chord rods 17 which are provided with a slot at each end. The end of lower chords 8 is also provided with a slot and a splice plate 15 is inserted into said slots and secured by a bolt and nut connection 16, as will appear from Figures 6A and 6B. Then the chord ends and splice plate can be firmly welded together.

Conveniently such joining of truss modules 2 may be carried out by the means of prefabricated joining modules 20 each of which consists of two upper chord rods 18, one lower chord rod 17, and at least four diagonal members 3. By means of such joining modules 20 the respective truss modules 2 may be easily and rapidly connected on the construction site to form the final space frame. Figures 4A and 4B show the space frame, as seen in a side elevation, and Figure 4B shows the joining procedure. Firstly the joining module 20 is attached to one truss module 2 by means of the splice plates 15 and bolt and nut" connections 16 for the lower chords, and by means of the support plates 13 and bolt and nut connections 14 for the upper chords. Subse¬ quently the next truss module is hoisted in place and disposed adjacent to the joining modules 20. The lower chords 8 are, as previously, secured by the means splice plates 15 and bolt and nut connections 16, and the upper the chords 5 are secured by means of the support plates 13 and bolt and nut connections 14. If desired, the supporting plates 13 may be welded to the upper chords 5 upon being secured. The joining of the lower chords 8 are normally all-welded.

Naturally, it is to be understood that the prefabricated section of the space frame 1 can, incorporate two or more parallel truss modules, since the width and length of the prefabricated section must above all be adapted for transport between the workshop and construction site. A major object is to maximize prefabrication in the workshop and minimize the assembling operations on the construction site.

Claims

CLAIMS:

1.

A space frame (1) constructed of tubular lower chords (8) and upper chords (5) extending in respective substantially parallel planes, and, relative to said planes, inclined diagonal members (3) connecting said upper and lower chords in respective nodal connection points (4, 6), c h a r a c t¬ e r i z e d i n that upper and lower chords (5, 8) and diagonal members (3) form respective intersecting truss modules (2), which extend at a predetermined mutual distance and form respective open fields or bays (10) between intersecting truss modules (2).

2.

A space frame as stated in claim 1, c h a r a c t e r ¬ i z e d i n that said open fields (10) between intersect¬ ing truss modules (2) adopt a square, rectangular, or rhombic configuration.

3.

A space frame as stated in claims 1 - 2, c h a r a c t ¬ e r i z e d i n that the number of nodal connection points (4) in the plane of upper chords (5) is twice the number of nodal connection points (6) in the plane of lower chords (8).

4.

A space frame as stated in claims 1 - 3, c h a r a c t ¬ e r i z e d i n that the number of upper chords (5) is twice of the number of lower chords (8).

5.

A space frame as stated in claims 1 - 4, c h a r a c t ¬ e r i z e d i n that each truss module (2) is connected to an adjacent module by joining modules (20), each of which comprises two upper chord rods (18), one lower chord rod (17), and at least four diagonal members.

6.

A space frame as stated in claims 1 - 5, c h a r a c t ¬ e r i z e d i n that each nodal connection point (4, 6) is all-welded.

7.

A space frame as stated in claims 1 - 6, c h a r a c t ¬ e r i z e d i n that the upper chord joints (11) forming the connection between respective truss modules (2) which are placed at a mutual distance, comprise a support plate (13) and bolt and nut connections (14).

8.

A space frame as stated in claims 1 - 6, c h a r a c t ¬ e r i z e d i n that the lower chord joints (12) forming the connection between respective truss modules (2) which are placed at a mutual distance, comprise a splice plate (15), bolt and nut connections (16) and a weld.