1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 7905-2:2000 Incorporat
2、ing Corrigendum No. 1 ICS 53.020.99; 91.080.10; 97.200.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Lifting equipment for performance, broadcast and similar applications Part 2: Specification for design and manufacture of aluminium and steel trusses and towersThis Britis
3、h Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 July 2000 BSI 07-2000 The following BSI references relate to the work on this standard: Committee reference MHE/3/13 Draf
4、t for comment 99/706164 DC ISBN 0 580 33160 1 BS 7905-2:2000 Amendments issued since publication Amd. No. Date Comments 11027 Corrigendum No. 1 July 2000 Corrections to inside front cover. Other corrections indicated by a sideline in the margin. Committees responsible for this British Standard The p
5、reparation of this British Standard was entrusted by Technical Committee MHE/3, Cranes and derricks, to Subcommittee MHE/3/13, Lifting equipment for performance, broadcast and similar applications, upon which the following bodies were represented: Association of British Theatre Technicians Broadcast
6、ing Entertainment Cinematograph and Theatre Union H.S.E ITV Association (ITVA) Lifting Equipment Engineers Association Professional Lighting and Sound Association Safety Assessment Federation Ltd Theatres Advisory CouncilBS 7905-2:2000 BSI 07-2000 i Contents Page Committees responsible Inside front
7、cover Foreword ii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Engineering 3 5 Manufacture 4 6 Care and use 4 Bibliography 5 Figure 1 Components of a typical truss or tower module 2ii BSI 07-2000 BS 7905-2:2000 Foreword This British Standard has been prepared by Subcommittee MHE/3/13, Liftin
8、g equipment for performance, broadcast and similar applications. There are no specific British Standards that cover the design, manufacture and use of aluminium or steel trusses in the entertainment industry. It should be noted that other British Standards may be relevant, depending on the applicati
9、on and intended use. In an attempt to improve safety and standards in the entertainment industry, the Entertainment Services and Technology Association (ESTA) of New York, USA, convened a series of meetings to prepare a draft standard for the American National Standards Institute. The preparation of
10、 the draft standard was entrusted to the Truss Team working as part of the Rigging Work Group for the Technical Standards Committee (TSC) of ESTA. The Truss Team generally consisted of manufacturers and their structural engineering advisors. This British Standard is based on the American draft stand
11、ard. It has been assumed in the drafting of this British Standard that execution of its design provisions is entrusted to appropriately qualified and experienced people, and that the fabrication is carried out by qualified and suitably experienced people and organizations. This British Standard spec
12、ifies a coordinated set of requirements that can also be a guide to government and other regulatory bodies and municipal authorities responsible for guarding and inspection of the equipment falling within its scope. The requirements concerning accident prevention are given both as mandatory and advi
13、sory provisions; compliance with both types may be required by employers of their employees. Safety codes and standards are intended to enhance public safety. Revisions result from committee consideration of factors such as technology advances, new data, and changing environmental and industry needs
14、. Revisions do not imply that previous editions were not adequate. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunit
15、y from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Sidelining in this document indicates the most rece
16、nt changes by amendment. BSI 07-2000 1 BS 7905-2:2000 | | | 1 Scope This British Standard covers design and manufacture of aluminium and steel trusses, towers and associated structural components such as tower head blocks, sleeve blocks, bases, and corner blocks in the entertainment industry. This B
17、ritish Standard covers truss beams and two dimensional ladder beams but does not cover individual, separate rigging hardware (half couplers, shackles, wire ropes, etc.). This British Standard covers a variety of uses that are confined to the entertainment industry and applies to a range of structure
18、s subjected to normal atmospheric conditions. This British Standard does not cover aerospace aluminium alloys, detailed design of castings, curved shell structures or structures subjected to severe thermal or chemical conditions. This British Standard is not intended to be used for the design of con
19、tainment vessels, airborne structures, or vessels, or for any application covered by another standard. Guidance on use of the equipment covered by this British Standard is given in BS 7906-2. Wherever “truss” is referred to in this British Standard, it equally applies to “tower” and vice versa. “Tru
20、ss” also applies to associated structural components. 2 Normative references The following normative documents contain provisions that, through reference in this text, constitute provisions of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these public
21、ations do not apply. For undated references, the latest edition of the publication referred to applies. BS 4-1:1993, Structural steel sections Specification for hot rolled sections. BS 1139-1.2:1990, Metal scaffolding Part 1: Tubes Section 1.2: Specification for aluminium tube. BS 5950 (all parts),
22、Structural use of steelwork in building. BS 6399 (all parts), Loading for buildings. BS 8118 (all parts), The structural use of aluminium. BS EN 287-1:1992, Approval testing of welders for fusion welding Steels. BS EN 287-2:1992, Approval testing of welders for fusion welding Aluminium and aluminium
23、 alloys. BS EN 754 (all parts), Aluminium and aluminium alloys Cold drawn rod/bar and tube. BS EN 755 (all parts), Aluminium and aluminium alloys Extruded rod/bar, tube and profiles. BS EN 30042:1994, Arc welded joints in aluminium and its weldable alloys Guidance on quality levels for imperfections
24、. BS EN 10056-1:1999, Specification for structural steel equal and unequal angles Dimensions. BS EN 10067:1997, Hot rolled bulb flats Dimensions and tolerances on shape, dimensions and mass. BS EN 10210-2:1997, Hot finished structural hollow sections of non-alloy and fine grain structural steels Tol
25、erances, dimensions and sectional properties. BS EN 25817:1992, Arc-welded joints in steel Guidance on quality levels for imperfections. 3 Definitions For the purposes of this British Standard, the following definitions apply. NOTE Figure 1 shows some components of a typical truss or tower module. 3
26、.1 abrasion loss of material due to wear 3.2 allowable load maximum permitted static equivalent load imposed on truss/tower in addition to the self-weight 3.3 camber intended vertical deviation of a truss, usually radiused 3.4 central point load (CPL) load applied at mid-span of the truss 3.5 chord
27、element of a truss module that carries axial forces associated with flexure or axial loading 3.6 competent person person with sufficient practical and theoretical knowledge and experience to carry out the persons duties, and who is aware of the limits of the persons competency, expertise and knowled
28、ge 3.7 connecting plates plates welded to the end frames of a truss or tower module, used to connect adjacent modules together 3.8 consumable item that requires regular replacement with use 3.9 crack crevice type discontinuity in a material 3.10 damage condition that adversely affects the intended u
29、se of a truss module (usually the load carrying capacity)2 BSI 07-2000 BS 7905-2:2000 Tophorizontal Panelpoint aka:node Horizontaldiagonal Vertical Chord Topview Sideview Bottomhorizontal Bottomview Verticaldiagonal Endview Internaldiagonal Figure 1 Components of a typical truss or tower module 3.11
30、 dent local deformation resulting in measurable change in cross section of member or element 3.12 design strength capacity of the elements of the structure to withstand normal design loading 3.13 diagonal elements of the truss or tower module that are at an angle to the main chords 3.14 drift test s
31、tandard test carried out on aluminium tubing to check structural integrity of the tube walls NOTE Drift testing highlights splits in the tube that can occur in the extrusion process. 3.15 dye penetrant test standard non-destructive test that highlights cracks in welds 3.16 dynamic load load that mov
32、es or vibrates 3.17 end plate plate on end of a truss module that allows connection to adjacent truss module(s) 3.18 incident occurrence in which damage to one or more truss modules can be sustained 3.19 module singular framed structure built up entirely from tension and compression members, arrange
33、d in panels to be stable under load 3.20 pinned connection end tube connection that uses a removable pin to form a connection between truss modules BSI 07-2000 3 BS 7905-2:2000 3.21 qualified person person who, by possession of a recognized degree or certificate of professional standing, or who by e
34、xtensive knowledge, training, and experience, has demonstrated the ability to solve problems relating to the subject matter and work 3.22 regular service normal use with repetitive assembling and dismantling 3.23 skin material cover to a truss structure NOTE A skin is normally used on a roof system.
35、 3.24 span distance between support points 3.25 static load load that is not moving 3.26 sweep intended lateral deviation of a truss, usually radiused 3.27 tower one or more modules, usually square or triangular, assembled vertically to carry primarily axial load 3.28 truss one or more modules, gene
36、rally horizontal, assembled to carry load over a distance, primarily in flexure 3.29 user person or company who assembles or uses truss or tower modules or systems 3.30 uniformly distributed load (UDL) load that is evenly spread over the length of a truss 4 Engineering 4.1 General Aluminium and stee
37、l trusses and towers shall be designed in accordance with this clause. 4.2 Design Aluminium trusses shall be designed in accordance with BS 8118. Steel trusses shall be designed in accordance with BS 5950. The design of either aluminium and steel trusses shall also conform to any other relevant stan
38、dard for the intended conditions of use. Welds shall be designed and detailed in accordance with the appropriate material standard (i.e. BS 8118 or BS 5950). Fasteners and other components of materials other than aluminium and steel shall be designed in accordance with standards relevant to the mate
39、rial. Design loading, including wind, shall be determined in accordance with BS 6399. All conditions of use considered in design shall be explicitly outlined in the engineering documentation provided by the manufacturer. Strength shall be established using design methods and/or by physical testing.
40、If testing is used to determine the strength of an element or structure, the test procedures shall conform to the appropriate material standard (i.e. BS 8118 or BS 5950). Truss structures shall conform to the following: Design of truss structures for single use: these structures shall be designed in
41、 accordance with either BS 8118 or BS 5950 as appropriate. Design of truss modules for repetitive use: the design strength determined in accordance with BS 8118 or BS 5950 shall be reduced by multiplying the strength by a factor of 0.85. The reduced design strength shall be greater than or equal to
42、the allowable load for intended loading conditions. Steel connectors for joining pieces of trussing together shall be either nut and bolt fasteners of minimum strength grade 8.8 throughout, or other fasteners of appropriate strength and design, that require at least two deliberate manual actions to
43、release (e.g. pin and clip). Quarter turn fasteners or other types of connector that require only a single action shall not be used. 4.3 Analysis 4.3.1 Analysis of the truss or tower structures for the intended load conditions shall be performed by calculation, modelling, physical testing, or a comb
44、ination of these methods. 4.3.2 Analysis shall consider the worst combination, application, and configuration of loads and effects possible within the guidelines for use. 4.3.3 Consideration shall be given to overall structural stability and bracing requirements for all applications within the guide
45、lines for use. 4.3.4 Consideration shall be given to the effects of eccentricities in element and module connections. 4.3.5 Deflections shall be calculated for the load conditions provided in the user information.4 BSI 07-2000 BS 7905-2:2000 | 4.4 Engineering documentation Engineering drawings of th
46、e truss or tower designs shall be developed and maintained by the manufacturer. Engineering drawings shall include dimensions, components, subassemblies, material types, fastener types, and specifications, weld sizes and types, and welding consumables. Engineering calculations, design notes and/or t
47、est results shall be developed and maintained to demonstrate conformity to this standard for the intended load conditions and uses. If a statement about design factor (commonly known as the “factor of safety”) is included in the information for use, then the manufacturer shall clearly state to what
48、condition the design factor refers. NOTE The design factor is usually defined as the ratio of the load required to cause failure to the allowable load on the structure or element. 5 Manufacture 5.1 General A level of quality in accordance with acceptable standard shall be maintained throughout the m
49、anufacturing process. Each truss shall have a mark so that it is traceable to the manufacturer if a defect occurs. 5.2 Materials Aluminium alloy shall conform to BS EN 754 and BS EN 755. Extruded aluminium alloy tubes shall be drift tested in accordance with BS 1139-1.2 to reduce the possibility of splitting. Steelwork shall conform to BS 4 and/or BS 10210-2, BS EN 10056-1 and BS EN 10067, ensuring component dimensions are within set limits and tolerances. 5.3 Welding Welders employed to manufacture aluminium truss or who are involved
