BS ISO 9611-1996 Acoustics - Characterization of sources of structure-borne sound with respect to sound radiation from connected structures - Measurement of velocity at the contact.pdf

1、BRITISH STANDARD BS ISO 9611:1996 Implementation of ISO 9611:1996 Acoustics Characterization of sources of structure-borne sound with respect to sound radiation from connected structures Measurement of velocity at the contact points of machinery when resiliently mounted ICS 17.140.20BSISO 9611:1996

2、This British Standard, having been prepared under the directionof the Health and Environment Sector Board, waspublished under the authorityof the Standards Boardand comes into effect on 15December 1996 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference

3、EH/1/4 Draft for comment 90/51746 DC ISBN 0 580 26879 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee EH/1, Acoustics, to Subcommittee EH/1/4, Machinery noise, upon which the following bodies were represented: Advanced

4、Manufacturing Technology Research Institute Agricultural Engineers Association British Cement Association British Compressed Air Society British Industrial Truck Association British Occupational Hygiene Society Construction Industry Research and Information Association Department of Environment (Bui

5、lding Research Establishment) Department of Trade and Industry (National Engineering Laboratory) Department of Trade and Industry (National Physical Laboratory) Department of Trade and Industry (Technology and Innovation Policy Division) Department of Transport Engineering Equipment and Materials Us

6、ers Association Engineering Industries Association Fan Manufacturers Association Federation of the Electronics Industry Federation of Manufacturers of Construction Equipment and Cranes Federation of Piling Specialists Health and Safety Executive Hevac Association Institute of Acoustics Institute of

7、Sound and Vibration Research Institution of Engineering Designers Institution of Mechanical Engineers National Specialist Contractors Council Rotating Electrical Machines Association (BEAMA Limited) Society of Environmental Engineers Society of Motor Manufacturers and Traders Limited University of L

8、iverpool University of Manchester Amendments issued since publication Amd. No. Date CommentsBSISO9611:1996 BSI 11-1998 i Contents Page Committees responsible Inside front cover National foreword ii Foreword iii Text of ISO 9611 1BSISO 9611:1996 ii BSI 11-1998 National foreword This British Standard

9、reproduces verbatim ISO 9611:1996 and implements it as the UK national standard. This British Standard is published under the direction of the Health and Environment Sector Board whose Technical Committee EH/1 has the responsibility to: aid enquirers to understand the text; present to the responsibl

10、e international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Custo

11、mer Services, BSI, 389 Chiswick High Road, London W4 4AL. 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 immunity from le

12、gal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages1 to 18, an inside back cover and abackcover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wil

13、l be indicated in the amendment table on theinside front cover.BSISO9611:1996 ii BSI 11-1998 Contents Page Foreword iii Introduction 1 1 Scope 2 2 Normative references 3 3 Definitions 3 4 Quantities to be measured 4 5 Test arrangement 4 6 Measuring equipment 7 7 Test procedure 9 8 Precision 10 9 Tes

14、t report 11 Annex A (normative) Determination of the lower limiting frequency, f 1 12 Annex B (normative) Determination of the upper limiting frequency, f 2 12 Annex C (normative) corrections if the accelerometers are not in the contact plane between the machinery foot and isolator 13 Annex D (norma

15、tive) Other connections between the machine andtestsurroundings 14 Annex E (informative) Background to the method 14 Annex F (informative) Reduction of the number of degrees of freedom 15 Annex G (informative) Selection of isolators and foundations 16 Annex H (informative) Application of the results

16、 16 Annex J (informative) Bibliography 18 Figure 1 Test arrangement 5 Figure 2 Position of the accelerometers for measurement of L vzand L Wy 5 Figure 3 Position of the accelerometers for measurementofL vz andL Wy whenthere is no space alongsidetheisolatorandthemachinery foot has a surface parallelt

17、othemounting face of the isolator 6 Figure 4 Location of the sensor for measurement of L vz 8 Figure 5 Possible locations of the sensor for measurement of L vy 8 Figure 6 Geometry for measurement of rotation and translations 10 Figure B.1 Minimum and maximum distances of the accelerometersusedindete

18、rmining f 2 12 Figure C.1 Velocities of points A and A9 at a distance h h being much smaller than D (h D/10) 13BSISO9611:1996 BSI 11-1998 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prep

19、aring International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in

20、liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Public

21、ation as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO 9611 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. Annex A to Annex D form an integral part of this International Standard. Annex

22、 E to Annex J are for information only.iv blankBSISO9611:1996 BSI 11-1998 1 Introduction This International Standard is one of a series of frame documents specifying various methods for the characterization of machines or equipment as sources of structure-borne sound with respect to sound radiation

23、from connected structures. The application of this International Standard to a certain family of machines needs additional requirements such as, for example, well-defined operating conditions given in a specific test code. This International Standard describes how, at each connection point for a res

24、ilient element, six components of the vibration can be measured and gives estimated standard deviations for their measurement uncertainty for frequencies in a given range of frequency. For a specific machine, a family of machines or for a specific application, fewer components may be sufficient to c

25、haracterize the source, thus the number of components measured could be reduced and the defined frequency range could be appropriately expanded or reduced. 0.1 General considerations Airborne sound in buildings, ships and vehicles and the underwater sound radiated by ships is very often caused by vi

26、brations of machinery or equipment. In general, such sound is emitted in at least two ways: a) directly from the outer surface of the machine into surrounding air; measurement methods for its determination are given in the series ISO 3740 to ISO 3747 and in ISO/TR 7849; and b) from structures connec

27、ted to the machine; this sound radiation results from structure-borne sound being emitted by the machine into the connected structures such as foundation, pipes, other coupled machines or linked auxiliary equipment. This International Standard deals according to b) with machines or equipment which a

28、re sources of structure-borne sound emission into connected structures with respect to airborne or liquid-borne sound radiation of connected structures. The measurement and evaluation of machinery vibration with respect to human response, trouble-free operation of coupled or connected machinery, as

29、well as structural fatigue and the lifetime of the machine itself are outside the scope of this International Standard. These fields are covered by International Standards of Technical Committee ISO/TC 108, Mechanical vibration and shock (see, for example, ISO 10816-1). A major problem associated wi

30、th the measurement of structure-borne sound emission is the choice of the quantities that characterize the “strength” of a source. The complete and fully accurate characterization of a source of structure-borne sound would involve an extremely large number of measurements; thus, one has somehow to t

31、rade accuracy against the simplicity of the method. In the context of standardization, emphasis is on simplicity; therefore an attempt has been made to describe the “strength” by a limited number of frequency-dependent quantities. Simplified source descriptions are possible when the two following as

32、sumptions are both satisfied: a) the connections of the machine with the surrounding structure can be treated as “points”; and b) there is a considerable mobility mismatch for all degrees of freedom of vibration at the connection points. In such cases, the sources can be described with a limited num

33、ber of force spectra if the source has relatively high mobilities, and with a limited number of velocity spectra if the source has relatively low mobilities as compared with the corresponding point mobilities of the receiving structure. An important feature is the fact that, for a certain range of r

34、eceiving structures, these source descriptions are independent of the precise characteristics of the receiving structure. For many practical purposes, the resulting source descriptions are still too complicated and a further simplification to one-, two- or three-frequency dependent quantities is nec

35、essary. The annexes give guidelines for the selection of circumstances under which further simplifications are possible. 0.2 Specific considerations This International Standard is one of a series specifying various methods for the characterization of sources of structure-borne sound (i.e. for the ch

36、aracterization of sources of vibrations) in the frequency range of audible sound. It gives a detailed description of a first method of a series 1) . The results of this International Standard may be used for the following purposes: a) obtaining data for preparing technical specifications; b) compari

37、ng the structure-borne sound emission of resiliently mounted machines of the same type and size; 1) International Standards describing the other methods and one giving a basic summary are in preparation.BSISO9611:1996 2 BSI 11-1998 c) obtaining input data for planning and noise purposes (e.g. input

38、data for the calculation of structure-borne sound transmission through resilient mountings into the connected structure). The method concerns the measurement of translational and angular velocity levels on the supports and other contact points of a machine which is mounted on resilient mountings (is

39、olators). In the frequency range of the method, the selected isolators, flexible connections and foundation are such that the vibration of the contact point is not significantly affected by their presence. Consequently the results represent the free vibratory velocity levels of the contact points. T

40、he method is further restricted by the requirement that a machine support or the contact structure of a machine to another flexible connection can be considered to vibrate as a rigid body. This implies an upper frequency limit. The direct application of the results is limited by the above restrictio

41、ns. In spite of these restrictions, there is a large variety of machines for which the method may be valuable. Examples are diesel engines, diesel generators, electric motors, compressors, fans, lathes and presses. For most of these machines, it will be possible to apply the method in the frequency

42、range between about 20 Hz and at least 1 kHz, which is the most important frequency range for practical problems of structure-borne sound. This International Standard describes measurements for all six degrees of freedom, i.e. six components of velocity (three orthogonal translations and three ortho

43、gonal rotations) at each contact. For specific machines and specific applications, some of these components can be neglected. There is significant experience with the method for some types of machines (e.g. diesel generators for shipboard applications) which provides the basis for this International

44、 Standard. This International Standard should be taken as a general document which may be used to define a standard measurement procedure for a specific class of machine. Details about the operational conditions of the machine under test, the type of mounting and foundation to be applied, the vibrat

45、ional components to be taken into account, the procedure for selecting or averaging data, checks of the test arrangements and the accuracy of the method and the applicability of the results should be given. The following International Standards were mainly consulted when preparing this International

46、 Standard: ISO 1683, ISO 2017, ISO 2041, ISO 5347-1 (and other parts), ISO 5348, ISO 7626-1, ISO 10816-1, IEC 651 and IEC 1260. To a certain extent, this International Standard is a further elaboration of ISO 10816-1, especially with respect to the solution of acoustical problems. 1 Scope 1.1 Genera

47、l This International Standard specifies an approximate method of characterizing sources of structure-borne sound by the measurement of one-third-octave-band free velocity level spectra (or, if appropriate, octave-band velocity level spectra) on the supports or other connection points of machines mou

48、nted on resilient isolators. This structure-borne sound emission is considered with respect to the airborne or liquid-borne sound radiation of structures connected to the source under test. The results are only valid for applications in which the machine is mounted on sufficiently soft isolators on

49、a sufficiently stiff and heavy foundation. NOTE 1More conditions are given in Annex H. A survey of the theoretical background is given in Annex E. It is possible to satisfy the requirements for the test arrangement in almost any surroundings. Velocities measured at defined contact points give no complete description of structure-borne sound emission of the machinery. But, under specific conditions as described in this International Standard for resiliently mounted machinery, they give a subset of the source data required for a characterization. The res