1、ANSI S2.25-2004AMERICAN NATIONAL STANDARDGuide for the Measurement, Reporting, and Evaluation of Hull and SuperstructureVibration in ShipsAccredited Standards Committee S2, Mechanical Vibration and ShockStandards SecretariatAcoustical Society of America35 Pinelawn Road, Suite 114 EMelville, NY 11747
2、-3177ANSI S2.25-2004Reaffirmed by ANSI June 18, 2009 Reaffirmed by ANSI September 24, 2014 The American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards
3、. The Acoustical Society of America (ASA) is an organization of scientists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI S2.25- 2004 (Revision of ANSI S2.25-2001) AMERICAN NATIONAL STANDARD Guide for the Measurement, R
4、eporting, and Evaluation of Hull and Superstructure Vibration in Ships Secretariat Acoustical Society of America Approved March 11, 2004 American National Standards Institute, Inc. Abstract This standard contains guidelines for limiting the hull and superstructure vibration of ships for the purposes
5、 of habitability and mechanical suitability. The mechanical suitability guidelines result in a suitable environment for installed equipment and preclude many major vibration problems, such as unbalance, misalignment, and other damage to the propulsion system. To obtain data to compare with the guide
6、lines, this standard also specifies data acquisition and processing procedures. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, and
7、 S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). The standards are published by the Acoustical Society of America through the American Institute
8、 of Physics as American National Standards after approval by their respective Standards Committees and the American National Standards Institute. These standards are developed and published as a public service to provide standards useful to the public, industry, and consumers, and to Federal, State,
9、 and local governments. Each of the accredited Standards Committees operating in accordance with procedures approved by American National Standards Institute (ANSI) is responsible for developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secretariat administers Co
10、mmittee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat arranges for thei
11、r publication and distribution. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially af
12、fected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use of an American National Standard is completely voluntary
13、. Their existence does not in any respect preclude anyone, whether he or she has approved the Standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This American National Standard may be revised or withdrawn
14、at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax:
15、 1 (631) 390-0217 E-mail: asastdsaip.org 2004 by Acoustical Society of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior writte
16、n permission of the publisher. For permission, address a request to the Standards Secretariat of the Acoustical Society of America.i Contents 1 Scope 1 2 Normative references 1 3 Definitions 2 4 Transducer locations . 3 4.1 Stern . 3 4.2 Superstructure . 3 4.3 Occupied spaces 3 4.4 Spaces with shipb
17、oard equipment . 3 5 Instrumentation characteristics 4 6 Test conditions . 4 7 Test procedure . 5 8 Data processing in general 5 8.1 Broadband rms velocity 6 8.2 Evaluating data expressed in terms of displacement and acceleration . 6 9 Report 6 10 Habitability . 7 10.1 Data processing for habitabili
18、ty 7 10.2 Habitability guidelines . 8 11 Mechanical suitability 8 11.1 Data processing for mechanical suitability 8 11.2 Guidelines for mechanical suitability 8 Annex A (Informative) Analysis relating ISO 10055:1996 sinusoidal test amplitudes to environmental guidelines 12 A.1 Background 12 A.2 S-N
19、Curve.12 A.3 Multiple directions .13 A.4 Crest factor .14 A.5 Guidelines 14 Annex B (Informative) Relating propeller pitch and mass unbalance to environmental guidelines .15 B.1 Background 15 B.2 Approach15 B.3 Balance requirements15 B.4 Pitch requirements 15 B.5 Vibration guidelines .17 Bibliograph
20、y .18 ii Tables Table 1 - Particulars of test shipa .10 Table 2 - Particulars of main diesel engines or turbine driven plantsa 11 Table Bl - Vibration due to mass unbalance .16 Table B2 Vibration due to pitch unbalance 16 Figures Figure A.1 S-N Curve for 70,000 psi UTS Steel 13 iii Foreword This For
21、eword is for information only, and is not a part of the American National Standard ANSI S2.25 - 2004 American National Standard Guide for the Measurement, Reporting, and Evaluation of Hull and Superstructure Vibration in Ships. This standard comprises a part of a group of definitions, standards, and
22、 specifications for use in mechanical vibration and shock. It was developed and approved by Accredited Standards Committee S2 Mechanical Vibration and Shock, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope
23、of Accredited Standards Committee S2 is as follows: Standards, specification, methods of measurement and test, and terminology in the field of mechanical vibration and shock, and condition monitoring and diagnostics of machines, but excluding those aspects which pertain to biological safety, toleran
24、ce and comfort. This standard is a revision of ANSI S2.25-2001, which has been technically revised. Updated values of accelerations and velocities in categories of spaces are recommended and are in line with those of ISO 6954:2000. Also, more accurate weightings for acceleration and velocity measure
25、ments for habitability are incorporated, which are consistent with ANSI S3.18-2002 Part 1/ISO 2631-1:1997. This standard is not comparable to any existing ISO Standard. At the time this Standard was submitted to Accredited Standards Committee S2, Mechanical Vibration and Shock for approval, the memb
26、ership was as follows: R.J. Peppin, Chair D.J. Evans, Vice-Chair S.B. Blaeser, Secretary Acoustical Society of America S.I Hayek .B.E. Douglas (Alt.) American Industrial Hygiene Association.J.J. Earshen D. Driscoll (Alt.) Bruel FAX: 631-390-0217; E-mail: asastdsaip.org v Introduction Shipboard vibra
27、tion is objectionable when it results in excessive stresses in structural or mechanical components, adversely affects the reliability or maintainability of machines or equipment aboard ships, interferes with crew duties, or reduces crew comfort. The primary purpose of this Standard is to provide gui
28、delines for the acceptability of a ships performance with respect to hull and superstructure vibration. This Standard also describes measurement and data processing procedures which will result in reliable data to compare with the guidelines. These guidelines apply to the evaluation of ship vibratio
29、n with respect to several factors. The evaluation of vibration with respect to habitability in this standard is based on the guidelines in ANSI S3.18-2002 Part1/ISO 2631-1:1997 3 and ISO 6954-2000 4. Unlike most vehicles, exposure to shipboard vibration normally lasts for days rather than hours. Gui
30、delines are established for spaces that should be comfortable. A guideline is also given to insure that all spaces, including normally unoccupied spaces, are not harmful for human exposure. The guidelines of this standard are the same for vertical and horizontal vibration 4. Evaluation of vibration
31、with respect to rotating machinery is based on ANSI 2.19-l999 2. Although there is no easily definable relationship between hull vibration and balancing requirements, if ANSI S2.19-1999 is satisfied, the guidelines of this Standard should easily be met. Conversely, if this Standard is not satisfied
32、due to a deficiency in a large rotating component, it would indicate a severe balancing or alignment problem. High vibration at the aft end of a vessel might be caused by propeller pitch unbalance. Evaluation of vibration with respect to equipment reliability is based on the requirements of IS0 1005
33、5-l996 7, extrapolated from a testing period to the expected life of the equipment. Again, there is no easily definable relationship between hull vibration and equipment reliability, but if both 7 and this standard are satisfied, environmental vibration should not be the cause of equipment reliabili
34、ty problems. AMERICAN NATIONAL STANDARD ANSI S2.25-2004 1 American National Standard Guide for the Measurement, Reporting, and Evaluation of Hull and Superstructure Vibration in Ships 1 Scope This Standard establishes uniform procedures for acquiring, processing, presenting, and evaluating shipboard
35、 vibration data for sea-going merchant ships of all lengths, and, where applicable, for inland ships and tugboats. It is applicable to both turbine and diesel-driven ships, with single or multiple shafts, but not to outboard-engine driven boats nor to air-driven vessels such as air-cushion vehicles.
36、 It contains guidelines for hull and super-structure vibration for: a) habitability; b) mechanical suitability. Data acquired in accordance with this Standard will be useful for: a) comparing ship specifications with acceptance trial data; b) comparing various vessels with each other; c) limited dia
37、gnostics of vibration problems; further development and improvement of vibration standards. 2 Normative references The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest editi
38、on of the referenced document (including any amendments) applies. 1 ANSI S2.1-2000/ISO 2041:1990 Nationally Adopted International Standard, Vibration and shock- Vocabulary. 2 ANSI S2.19-1999 American National Standard Mechanical Vibration Balance Quality Requirements of Rigid Rotors, Part 1: Determi
39、nation of Permissible Residual Unbalance, Including Marine Applications. 3 ANSI S3.18-2002 Part 1/ISO 2631-1:1997, American National Standard Mechanical Vibration and Shock Evaluation of Human Exposure to Whole-Body Vibration Part 1: General Requirements. 4 ISO 6954:2000 Mechanical vibration and sho
40、ck - Guidelines for the measurement, reporting and evaluation of vibration on passenger and merchant ships. 5 ISO 8041:1990 Human response to vibration Measuring instrumentation. ANSI S2.25-2004 2 6 ISO 8041/AMD 1:1999 Human response to vibration Measuring instrumentation Amendment 1. 7 IS0 10055:l9
41、96, Mechanical vibration-Vibration testing requirements for shipboard equipment and machinery components. 3 Definitions For the purposes of this standard, the terms and definitions given in ANSI S2.1-2000/ISO 2041:1990 and the following apply: 3.1 critical speed. A ships propeller shaft rotational s
42、peed in rpm at which a major resonance of the hull or propulsion system is encountered. 3.2 environmental vibration. The vibration on board a ship to which the ships crew and installed equipment are subjected while the ship is operating. 3.3 free route. That condition achieved when the ship is proce
43、eding at a constant speed and course with minimum throttle or helm adjustment. 3.4 frequency spectrum. A plot of the vibration amplitude versus frequencies occurring in a dynamic signal for a specified time period. Spectra are normally obtained from Fast Fourier Transforms (FFTs) of segments of the
44、signal, and the FFTs averaged over a representative sample length. 3.5 hull girder. The primary hull structure such as the shell plating and continuous strength decks contributing to the flexural rigidity of the hull and the static and dynamic behavior of which can be described by a free-free non-un
45、iform beam approximation. 3.6 hull girder vibration. That component of vibration existing at any transverse plane of the hull in which there is little or no relative motion between elements intersected by the plane. 3.7 local vibration. The dynamic response of a structural element, deck, bulkhead or
46、 piece of equipment which is significantly greater than that of the hull girder at that location. 3.8 root-mean-square (rms) value. The rms value of a single valued function over an interval is the square root of the average of the squared values of the function over the interval. (For a vibration r
47、ecord, it is the rms value of all points in the record, not just the peaks.) 3.9 slamming. The impact of a ships hull upon reentering the sea after having broached the surface. Usually occurs in rough seas and results in large magnitude transient vibrations of the lower modes of flexural vibration o
48、f the hull girder. 3.10 vibration severity. A value, or set of values, such as a maximum value, average or rms value, or other parameter that is descriptive of the vibration. (In this standard, the rms value of vibratory velocity over a frequency range of 1 Hz to 100 Hz is the primary measure of sev
49、erity.) 3.11 weighting function. A function of frequency which is multiplied by the vibrations in a frequency spectrum to obtain a “weighted spectrum“ in which the vibrations reflect comparable severities. ANSI S2.25 - 2004 3 4 Transducer locations Many of the measurements specified in this Standard are based on the fact that the responses of ship hulls in the lower modes of vibration are usually those of free-free beams. The stern is of primary interest because it usually has large
