1、BSI Standards PublicationBS EN 16603-32-11:2014Space engineering Modalsurvey assessmentBS EN 16603-32-11:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN16603-32-11:2014.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/68, Spac
2、e systems and operations.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014.
3、Published by BSI StandardsLimited 2014ISBN 978 0 580 83985 6ICS 49.140Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2014.Amendments issued since pub
4、licationDate Text affectedBS EN 16603-32-11:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16603-32-11 August 2014 ICS 49.140English version Space engineering - Modal survey assessment Ingnierie spatiale - Evaluation des modes vibratoires Raumfahrttechnik - Modale Prfungsbewertung This Eur
5、opean Standard was approved by CEN on 23 February 2014. CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographica
6、l references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN and CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the resp
7、onsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cypr
8、us, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kin
9、gdom. CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN/CENELEC All rights of exploitation in any form and by any means reserved worldwide for CEN national Members and for CENELEC Members. Ref. No. EN 16603-32-11:2014 EBS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 2 Table of
10、contents Foreword 5 1 Scope. 6 2 Normative references . 7 3 Terms, definitions and abbreviated terms 8 3.1 Terms from other standards 8 3.2 Terms specific to the present standard . 8 3.3 Abbreviated terms. 22 3.4 Notation 23 4 General objectives and requirements.254.1 Modal survey test objectives .
11、25 4.1.1 Overview . 25 4.1.2 General . 25 4.1.3 Verification of design frequency 25 4.1.4 Mathematical model validation 26 4.1.5 Troubleshooting vibration problems 26 4.1.6 Verification of design modifications . 26 4.1.7 Failure detection . 27 4.2 Modal survey test general requirements . 27 4.2.1 Te
12、st set-up 27 4.2.2 Boundary conditions 28 4.2.3 Environmental conditions 28 4.2.4 Test facility certification . 28 4.2.5 Safety 29 4.2.6 Test success criteria . 29 5 Modal survey test procedures . 31 5.1 General . 31 5.2 Test planning 31 5.2.1 Test planning 31 5.2.2 Pre-test activities . 33 BS EN 16
13、603-32-11:2014EN 16603-32-11:2014 (E) 3 5.2.3 Test activities 33 5.2.4 Post-test activities . 34 5.3 Test set-up . 34 5.3.1 Definition of the test set-up 34 5.3.2 Test boundary conditions 34 5.3.3 Test instrumentation 36 5.3.4 Excitation plan . 37 5.3.5 Test hardware and software 38 5.4 Test perform
14、ance 38 5.4.1 Test . 38 5.4.2 Excitation system 38 5.4.3 Excitation signal 39 5.4.4 Linearity and structural integrity. 40 5.4.5 Measurement errors 40 5.5 Modal identification methods 41 5.6 Modal parameter estimation methods . 42 5.7 Test data 42 5.7.1 Quality checks . 42 5.7.2 Generalized paramete
15、rs 44 5.7.3 Effective masses . 44 5.7.4 Data storage and delivery . 45 5.8 Test-analysis correlation . 46 5.8.1 Purpose 46 5.8.2 Criteria for mathematical model quality . 47 6 Pre-test analysis . 49 6.1 Purpose 49 6.2 Modal survey test FEM . 49 6.2.1 Purpose 49 6.2.2 Reduction of the detailed FEM 50
16、 6.3 Test analysis model (TAM) . 52 6.3.1 Purpose 52 6.3.2 TAM accuracy . 53 6.3.3 Measurement point plan (MPP) . 53 6.3.4 Test predictions . 54 6.3.5 Test fixture participation 54 6.4 Documentation . 55 6.4.1 FEM documentation 55 BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 4 6.4.2 TAM documentati
17、on 55 Annex A (informative) Excitation signals . 57 A.1 Overview 57 A.2 Purpose and classification 57 A.3 Excitation methods . 58 Annex B (informative) Estimation methods for modal parameters . 61 B.1 Overview 61 B.2 Theoretical background and overview. 61 B.3 Frequency domain methods . 67 B.4 Time
18、domain methods 71 Annex C (informative) Modal test - mathematical model verification checklist . 74 Annex D (informative) References 76 Bibliography . 77 Figures Figure 5-1: Test planning activities . 32 Figure 5-2: Comparison of mode indicator functions (MIF) according to Breitbach and Hunt 43 Figu
19、re 6-1: Modal survey pre-test analysis activities . 50 Tables Table 5-1: Test objectives and associated requirements for the test boundary conditions . 35 Table 5-2: Most commonly used correlation techniques . 46 Table 5-3: Test-analysis correlation quality criteria . 48 Table 5-4: Reduced mathemati
20、cal model quality criteria . 48 Table 6-1: Advantages and disadvantages of model reduction techniques . 52 Table B-1 : Overview and classification of commonly used modal parameter estimation methods . 64 Table B-2 : Advantages and disadvantages of the time and frequency domain methods 65 Table B-3 :
21、 Advantages and disadvantages of single and multiple degree of freedom methods 66 Table B-4 : Other aspects of selecting a modal parameter estimation method . 67 Table C-1 : Verification checklist for mathematical models supporting modal survey tests . 75 BS EN 16603-32-11:2014EN 16603-32-11:2014 (E
22、) 5 Foreword This document (EN 16603-32-11:2014) has been prepared by Technical Committee CEN/CLC/TC 5 “Space”, the secretariat of which is held by DIN. This standard (EN 16603-32-11:2014) originates from ECSS-E-ST-32-11C. This European Standard shall be given the status of a national standard, eith
23、er by publication of an identical text or by endorsement, at the latest by February 2015, and conflicting national standards shall be withdrawn at the latest by February 2015. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN an
24、d/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. This document has been developed to cover specifically space systems and has ther
25、efore precedence over any EN covering the same scope but with a wider domain of applicability (e.g. : aerospace). According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgar
26、ia, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turk
27、ey and the United Kingdom. BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 6 1 Scope This Standard specifies the basic requirements to be imposed on the performance and assessment of modal survey tests in space programmes. It defines the terminology for the activities involved and includes provisions
28、for the requirement implementation. This Standard specifies the tasks to be performed when preparing, executing and evaluating a modal survey test, in order to ensure that the objectives of the test are satisfied and valid data is obtained to identify the dynamic characteristics of the test article.
29、 This standard may be tailored for the specific characteristics and constrains of a space project in conformance with ECSS-S-ST-00. BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 7 2 Normative references The following normative documents contain provisions which, through reference in this text, const
30、itute provisions of this ECSS Standard. For dated references, subsequent amendments to, or revision of any of these publications, do not apply. However, parties to agreements based on this ECSS Standard are encouraged to investigate the possibility of applying the more recent editions of the normati
31、ve documents indicated below. For undated references, the latest edition of the publication referred to applies. EN reference Reference in text Title EN 16601-00-01 ECSS-S-ST-00-01 ECSS system Glossary of terms EN 16603-10-03 ECSS-E-ST-10-03 Space engineering Testing EN 16603-32 ECSS-E-ST-32 Space e
32、ngineering Structural general requirements BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 8 3 Terms, definitions and abbreviated terms 3.1 Terms from other standards For the purpose of this Standard, the terms and definitions from ECSS-S-ST-00-01 apply. 3.2 Terms specific to the present standard 3.2.
33、1 accelerance ratio of the output acceleration spectrum to the input force spectrum NOTE 1 Accelerance is computed as follows: )()()(FXA=where )(Xis the output acceleration spectrum; )(F is the input force spectrum. NOTE 2 The accelerance is also called “inertance” and it is the inverse of the appar
34、ent mass (see 3.2.2). 3.2.2 apparent mass ratio of the input force spectrum to the output acceleration spectrum NOTE 1 Apparent mass is computed as follows: )()()(=XFMwhere )(F is the input force spectrum; )(Xis the output acceleration spectrum. NOTE 2 The apparent mass is also called “dynamic mass”
35、, and it is the inverse of the accelerance (see 3.2.1). BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 9 3.2.3 auto modal assurance criterion AutoMAC measure of the degree of correlation between two mode shapes of the same mode shape set NOTE 1 For example, test mode shapes or analysis mode shapes. N
36、OTE 2 The AutoMAC is a specific case of the MAC (see 3.2.26); the AutoMAC matrix is symmetric. NOTE 3 The AutoMAC is particularly useful for assessing whether a given selection of DOFs is adequate for MAC evaluations employing two different sets of mode shapes (e.g. test and analysis). 3.2.4 coheren
37、ce function measure of the degree of linear, noise-free relationship between the measured system input and output signals at each frequency NOTE 1 The coherence function is defined as )()()()(2ffxxfxSSS=where is the frequency; Sff () is the power spectrum of the input signal; Sxx () is the power spe
38、ctrum of the output signal; Sxf () is the input-output cross spectrum. NOTE 2 2 ()=1 indicates a linear, noise-free relationship between input and output. NOTE 3 2 ()=0 indicates a non causal relationship between input and output. 3.2.5 complex mode shape modal vector of a non-proportionally damped
39、system NOTE 1 For complex mode shapes, any phase relationship can exits between different parts of the structure. NOTE 2 Complex mode shapes can be considered to be propagating waves with no stationary node lines. 3.2.6 complex mode indicator function indicator of the existence of real or complex mo
40、des and their relative magnitudes NOTE The complex mode indicator function has extended functionality to estimate approximate modal parameters. BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 10 3.2.7 co-ordinate modal assurance criterion CoMAC measure of the correlation of the a given DOF of two diff
41、erent sets of mode shapes over a number of comparable-paired mode shapes NOTE 1 The coordinate modal assurance criterion for DOF j is defined as: ( ) ( )=mrAjrmrXjrmrAjrXjrjCoMAC121221)( where Ajr is the mode shape coefficient for DOF j for mode r of set A; Xjr is the mode shape coefficient for DOF
42、j for mode r of set X; r is the index of the correlated mode pairs. For example, mode shapes X and A are test and analysis mode shapes, respectively. NOTE 2 CoMAC = 1 indicates perfect correlation. NOTE 3 The results can be considered to be meaningful only when the CoMAC is applied to matched modes,
43、 i.e. for correlated mode pairs. 3.2.8 damping dissipation of oscillatory or vibratory energy with motion or with time 3.2.9 damped natural frequency frequency of free vibrations of a damped linear mechanical system 3.2.10 driving point residue calculated quantity that defines the most appropriate e
44、xciter positions NOTE The magnitude of the driving point residue for a location is defined as: drrjrjrmvr22=where rjr is the driving point residue of DOF j for mode r; vjr is the mode shape coefficient of DOF j for mode r; mr is the modal mass for mode r; dr is the damped natural frequency for mode
45、r. BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 11 3.2.11 dynamic compliance ratio of the output displacement spectrum to the input force spectrum NOTE 1 Dynamic compliance is computed as follows: )()()(FXH =where X() is the output displacement spectrum; F() is the input force spectrum. NOTE 2 The
46、dynamic compliance is also called dynamic flexibility, and it is the inverse of the dynamic stiffness (see 3.2.12). 3.2.12 dynamic stiffness ratio of the input force spectrum to the output displacement spectrum NOTE 1 Dynamic stiffness is computed as follows: )()()(XFK =where F() is the input force
47、spectrum; X() is the output displacement spectrum. NOTE 2 The dynamic stiffness is the inverse of the dynamic compliance (see 3.2.11). 3.2.13 effective modal massmeasure of the mass portion associated to the mode shape with respect to a reference support point NOTE 1 The six effective masses for a n
48、ormal mode, r, are the diagonal values of the modal mass matrix. rrTrrmLLM =where Lr is the modal participation factor: rTRBrML = ; mr is the generalised mass: rTrrmm = ; r, is the elastic mode r; , is the rigid body mode. NOTE 2 The sum of the effective masses provides an indication of the complete
49、ness of the measured modes, since the accumulated effective mass contributions from all modes equal the total structural mass and inertia for each of the six translatory and rotatory DOFs, respectively. BS EN 16603-32-11:2014EN 16603-32-11:2014 (E) 12 3.2.14 eigenfrequency See natural frequency 3.2.15 finite element model FEM mathematical representation of a physical structure or system where the distributed physical properties are represented by a discrete model
