ISO 8686-1-2012 Cranes - Design principles for loads and load combinations - Part 1 General《起重机 载荷和载荷组合的设计原则 第1部分 总则》.pdf

《ISO 8686-1-2012 Cranes - Design principles for loads and load combinations - Part 1 General《起重机 载荷和载荷组合的设计原则 第1部分 总则》.pdf》由会员分享，可在线阅读，更多相关《ISO 8686-1-2012 Cranes - Design principles for loads and load combinations - Part 1 General《起重机 载荷和载荷组合的设计原则 第1部分 总则》.pdf（54页珍藏版）》请在麦多课文档分享上搜索。

1、 ISO 2012 Cranes Design principles for loads and load combinations Part 1: General Appareils de levage charge suspendue Principes de calcul des charges et des combinaisons de charge Partie 1: Gnralits INTERNATIONAL STANDARD ISO 8686-1 Second edition 2012-12-15 Reference number ISO 8686-1:2012(E) ISO

2、 8686-1:2012(E)ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permiss

3、ion in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO 8686-1:2012(E) ISO 2012 Al

4、l rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Symbols 2 5 General 2 5.1 General principles 2 5.2 Methods of proof of competence calculations . 3 5.3 Assessment of loads . 3 5.4 Categories of loads . 4 6 Loads and applicable factor

5、s . 4 6.1 Regular loads 4 6.2 Occasional loads. 9 6.3 Exceptional loads .10 6.4 Miscellaneous loads .13 7 Principles of choice of load combinations 13 7.1 Basic considerations .13 7.2 Load combinations during erection, dismantling and transport .17 7.3 Application of Table 3 17 7.4 Partial safety fa

6、ctors for the proof of rigid body stability .20 Annex A (normative) Application of allowable stress method and limit state method of design .21 Annex B (informative) General guidance on application of dynamic factors 26 Annex C (informative) Example of model for estimating value of dynamic factor 4f

7、or cranes travelling on rails 27 Annex D (informative) Example of determination of loads caused by acceleration 31 Annex E (informative) Example of method for analysing loads due to skewing 40 Annex F (informative) Illustration of types of hoist drives 46 Bibliography .49 ISO 8686-1:2012(E) Foreword

8、 ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical

9、 committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of elec

10、trotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the

11、 member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for iden

12、tifying any or all such patent rights. ISO 8686-1 was prepared by Technical Committee ISO/TC 96, Cranes, Subcommittee SC 10, Design Principles and requirements. This second edition cancels and replaces the first edition ( ISO 8686-1:1989), which has been technically revised. ISO 8686 consists of the

13、 following parts, under the general title Cranes Design principles for loads and load combinations: Part 1: General Part 2: Mobile cranes Part 3: Tower cranes Part 4: Jib cranes Part 5: Overhead travelling and portal bridge cranesiv ISO 2012 All rights reserved INTERNATIONAL ST ANDARD ISO 8686-1:201

14、2(E) Cranes Design principles for loads and load combinations Part 1: General 1 Scope This part of ISO 8686 establishes general methods for the calculating loads and principles to be used in the selection of load combinations for proofs of competence in accordance with ISO 20332 for the structural a

15、nd mechanical components of cranes as defined in ISO 4306-1. It is based on rigid body kinetic analysis and elastostatic analysis but expressly permits the use of more advanced methods (calculations or tests) to evaluate the effects of loads and load combinations, and the values of dynamic load fact

16、ors, where it can be demonstrated that these provide at least equivalent levels of competence. This part of ISO 8686 provides for two distinct kinds of application: a) the general form, content and ranges of parameter values for more specific standards to be developed for specific types of cranes; b

17、) a framework for agreement on loads and load combinations between a designer or manufacturer and a crane purchaser for those types of cranes where specific standards do not exist. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and ar

18、e indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 4302, Cranes Wind load assessment ISO 4306 (all parts), Lifting appliances Vocabulary ISO 4310, Cra

19、nes Test code and procedures ISO 20332, Cranes Proof of competence of steel structures 3 T erms an d definiti ons For the purposes of this document, the definitions given in ISO 4306 and the following apply. 3.1 load or loads external or internal actions in the form of forces, displacements or tempe

20、rature, which cause stresses in the structural or mechanical components of the crane 3.2 analysisstudy of the movement and the inner forces of systems modelled by elements that are assumed to be non-elastic ISO 2012 All rights reserved 1 ISO 8686-1:2012(E) 3.3 analysisstudy of the relative elastic d

21、isplacements (distortion), movement and the inner forces of systems modelled by elements that are assumed to be elastic 4 Symbols The main symbols used in this part of ISO 8686 are given in Table 1. Table 1 Main symbols Symbol Description Reference Factors for dynamic effects Various 1 Factors for h

22、oisting and gravity effects acting on the mass of the crane 6.1.1 2 Factor for hoisting a grounded load 6.1.2.1 3 Factor for dynamic effects of sudden release of part of load 6.1.2.2 4 Factor for dynamic effects of travelling on an uneven surface 6.1.3.2 5 Factor for dynamic loads arising from accel

23、eration of crane drives 6.1.4 6 Factor for effects of dynamic load tests 6.3.2 7 Factor for elastic effects arising from collision with buffers 6.3.3 9 Factor for dynamic effects from unintentional loss of payload 6.3.5 HC1 to HC4 Hoisting classes assigned to cranes 6.1.2.2 to 6.1.2.1.4 2 Factor ass

24、igned to hoisting class 6.1.2.1.1 to 6.1.2.1.2; 6.1.2.1.5 3 Term used in determining the value of 3 6.1.2.2 v h Steady hoisting speed, in metres per second 6.1.2.1.3 (Table 2b) F x , F x2 , F x4 Buffer forces 6.3.3, Annex D f Coefficients for calculating allowable stresses 7.3.2, Table 3, A.2 to A.3

25、 p Partial safety factor 7.3.3, Table 3, 7.3.7.2, 7.3.8, A.2 to A.3 m Resistance coefficient Table 3, Annex A n Coefficient for high-risk applications 7.3.6, Annex A m Mass of pay load 6.1.2.2 m H Mass of the gross load 6.1.2.1.1, 6.1.2.3, 6.3.1, Annex D m = m H m H Mass of that part of the hoist lo

26、ad remaining suspended from the crane 6.3.1NOTE Further symbols are used in the annexes and are defined therein. 5 General 5.1 General principles The objective of proof of competence calculations carried out in accordance with this part of ISO 8686 is to determine mathematically that a crane will be

27、 competent to perform in practice when operated in compliance with the manufacturers instructions.2 ISO 2012 All rights reserved ISO 8686-1:2012(E) The basis for such proof against failure (e.g. by yielding, elastic instability or fatigue) is the comparison between calculated stresses induced by loa

28、ds and the corresponding calculated strengths of the constituent structural and mechanical components of the crane. Proof against failure may also be required in respect of overturning stability. Here, the comparison is made between the calculated overturning moments induced by loads and the calcula

29、ted resistance to overturning provided by the crane. In addition, there may be limitations on forces that are necessary to ensure the stability and/or to avoid unwanted displacement of portions of the crane or of the crane itself, for example, the jib support ropes becoming unloaded or the crane sli

30、ding. The effects of differences between actual and ideal geometry of mechanical and structural systems (e.g. the effect of tolerances, settlements, etc.) shall be taken into account. However, they shall be included specifically in proof of competence calculations only where, in conjunction with app

31、lied loads, they may cause stresses that exceed specified limits. When applying this part of ISO 8686 to the different types of cranes, operating in the same service and environmental conditions, equivalent resistance to failure should be sought. 5.2 Methods of proof of competence calculations There

32、 are two general approaches to structural design or proof of competence. a) The allowable stress method: where the design stresses induced by combined loads are compared with allowable stresses established for the type of member or condition being examined. The assignment of allowable stress is made

33、 on the basis of service experience with consideration for protection against failure due, for example, to yielding, elastic instability or fatigue. b) The limit state method: where partial safety factors are used to amplify loads before they are combined and compared with the limit states imposed,

34、for example, by yielding or elastic instability. The partial safety factor for each load is established on the basis of probability and the degree of accuracy with which the load can be determined. Limit state values comprise the characteristic strength of the member reduced to reflect statistical v

35、ariations in its strength and geometric parameters. This method is a prerequisite if this part of ISO 8686 is applied together with ISO 20332 and/or the 2nd order method. Annex A gives a more detailed description of the application of the two methods. 5.3 Assessment of loads To calculate stresses fr

36、om applied loads, an appropriate model of the crane shall be used. Under the provisions of this part of ISO 8686, loads which cause time variant load effects are assessed as equivalent static loads from experience, experiments or by calculation. A rigid body kinetic analysis can be used with dynamic

37、 factors to estimate the forces necessary to simulate the response of the elastic system. Alternatively, either elasto-kinetic analysis or field measurements can be carried out, but to reflect the operating regime, a realistic model of the actions of the crane operator may be required. For both the

38、allowable stress and limit state methods, and for considerations of stability and displacements, loads, load combinations and load factors should be assigned either on the basis of experience, with consideration of other International Standards or, if applicable, on the basis of experimental or stat

39、istical data. The parameters used in this part of ISO 8686 are considered to be deterministic. Where a specific loading cannot occur (for example, wind loading on a crane used indoors) then that loading can be ignored in the proof of competence calculations. Similarly, loadings can be modified when

40、they result from a) conditions prohibited in the crane instructions, b) features not present in the design, or c) conditions prevented or suppressed by the design of the crane. ISO 2012 All rights reserved 3 ISO 8686-1:2012(E) If a probabilistic proof of competence calculation is used, the relevant

41、conditions, particularly the acceptable probability of failure, shall be stated. 5.4 Categories of loads Clause 6 gives loads and ranges of values for the factors used in proof of competence calculations when determining load effects. NOTE Individual values for specific types of cranes, selected fro

42、m these ranges, are to be found in the parts of ISO 8686 applicable to specific crane types (see Foreword). The loads acting on a lifting crane are divided into the categories of regular, occasional, exceptional and miscellaneous. Individual loads are considered only when and if they are relevant to

43、 the crane under consideration or to its usage, as follows. a) Regular loads, occurring during normal operation, shall be considered in proof of competence calculations against failure by yielding, elastic instability and, when applicable, against fatigue. They result from gravity and from accelerat

44、ion or deceleration produced by drives and brakes acting on the masses of the crane and the hoist load, as well as from displacements. b) Occasional loads and effects which occur infrequently may usually be neglected in fatigue evaluations. They include loads induced by in-service wind, snow and ice

45、, temperature and skewing. c) Exceptional loads and their effects are also infrequent and may likewise usually be excluded from fatigue consideration. They include loads caused by testing, out-of service wind, buffer forces and tilting, as well as from emergency cut-out, failure of drive components

46、and external excitation of the crane foundation. d) Miscellaneous loads include erection and dismantling loads as well as loads on platforms and means of access. The category in which a load is placed is not necessarily an indication of the importance or criticality of that load: erection and disman

47、tling loads, although in the last category, shall be given particular attention, as a substantial portion of accidents occur during those phases of operation. 6 Loads and applicable factors 6.1 Regular loads 6.1.1 Hoisting and gravity effects acting on the mass of the crane The mass of the crane inc

48、ludes those components which are always in place during operation, except for the payload itself (see 6.1.2). For some cranes or applications, it may be necessary to add mass to account for encrustation of materials, such as coal or similar dust, which build up on the crane or its parts. The gravita

49、tional force induced by the mass of the crane (dead weight) shall be multiplied by a factor, 1 , where 1 10 01 aa , (1) In this way the vibrational excitement of the crane structure, when lifting the pay load off the ground, is taken into account. There are always two values for the factor, in order to reflect both the upper and lower reaches of the vibrational pulses. Factor 1shall be used in the design of the crane structure and its supports; in some cases, both values o