BS ISO 14954-2006 Space systems - Dynamic and static analysis - Exchange of mathematical models《空间系统 动态和静态分析 数学模型的交换》.pdf

1、BRITISH STANDARDBS ISO 14954:2005Space systems Dynamic and static analysis Exchange of mathematical modelsICS 49.140g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g

2、43g55g3g47g36g58BS ISO 14954:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 April 2006 BSI 2006ISBN 0 580 48171 9National forewordThis British Standard reproduces verbatim ISO 14954:2005 and implements it as the UK national standard.T

3、he UK participation in its preparation was entrusted to Technical Committee ACE/68, Space systems and operations, which has the responsibility to:A list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement in

4、ternational publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to inc

5、lude all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enqu

6、iries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to13 a

7、nd a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsReference numberISO 14954:2005(E)INTERNATIONAL STANDARD ISO14954First edition2005-02-01Space systems Dynamic and static analysis Ex

8、change of mathematical models Systmes spatiaux Analyse dynamique et statique change de modles mathmatiques BS ISO 14954:2005ii iiiContents Page Foreword iv 1 Scope 1 2 Normative references . 1 3 Terms, definitions, symbols, and abbreviated terms 1 4 General description of models 3 5 General requirem

9、ents . 3 6 Condensation methods 5 7 Model delivery checks 8 8 Requested outputs 10 9 Size limitations 10 10 Delivery formats 10 BS ISO 14954:2005iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work o

10、f preparing 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-governmenta

11、l, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main

12、 task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Atte

13、ntion 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 identifying any or all such patent rights. ISO 14954 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14,

14、 Space systems and operations. BS ISO 14954:20051Space systems Dynamic and static analysis Exchange of mathematical models 1 Scope This International Standard normalizes the exchange of mathematical models between payload contractors (PLC) and launch service providers (LSP). It identifies standard m

15、ethods for modelling the dynamic behaviour of both launch vehicles (LV) and payload (PL), particularly when they are coupled prior to launch and during the early moments of the launch phase. In standard mode, the delivered models represent dynamic and static behaviour at the launcher interface. The

16、requirements provided in this International Standard are the minimum necessary for dynamic coupled analysis. They may not be sufficient for stress analysis. The payload models are full integrated models from the different parts of the payload under the payload contractor authority, including also th

17、eir own adapter to LV interface in the case that the adapter is a part of the payload. This International Standard does not include the validation of PL models. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, onl

18、y the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 646, Information technology ISO 7-bit coded character set for information interchange 3 Terms, definitions, symbols, and abbreviated terms 3.1 Terms and defi

19、nitions For the purposes of this document, the following terms and definitions apply. 3.1.1 payload system that is launched by a launch vehicle EXAMPLES Satellite, spacecraft, space probe. 3.1.2 payload contractor organization in charge of a payload 3.1.2 launch service provider organization that co

20、nducts a launch with a launch vehicle BS ISO 14954:20052 3.2 Abbreviated terms ATM acceleration transformation matrix CoG centre of gravity DoF degree of freedom DTM displacement transformation matrix EOF end of file ICD interface control document LSP launch service provider LTM load transformation

21、matrix LV launch vehicle OTM output transformation matrix PL payload PLC payload contractor SI International System of Units 3.3 Symbols A acceleration transformation matrix C damping matrix D displacement transformation matrix K stiffness matrix KRstiffness matrix of rigid body modes,TRRR=KK L load

22、 transformation matrix M mass matrix MRmass matrix of rigid body modes, TRRR=MM Sestrain energy qisinternal degrees of freedom qjdegrees of freedom of the interface Rmatrix of rigid body modes kmodal coordinates BS ISO 14954:200534 General description of models 4.1 Matrices The mathematical model of

23、 a PL shall be made of three matrices mass matrix (M), stiffness matrix (K), and damping matrix (C). It shall be sufficient to characterize the dynamic and static behaviour of the structure, assuming that no external forces are applied to the payload except through the LV-PL interface. A modal synth

24、esis method is a typical procedure used to generate a reduced mathematical model. Additional matrices may be provided in order to reconstitute acceleration, displacement or load in the PL. These matrices are identified as OTMs in the following clauses. 4.2 Types of models 4.2.1 Physical models Physi

25、cal models shall be represented by matrices, the dynamic and static behaviour of which is described solely by the DoFs related to physical displacement at nodal points, including all interface points. 4.2.2 Modal models Modal models shall be represented by matrices, the dynamic and static behaviour

26、of which is described solely by a mix of physical and modal DoFs (representing the modes of the structure fixed at previous physical DoFs). Only interface DoFs are physical DoFs. 4.2.3 Hybrid models Hybrid models are extensions of modal models for which internal physical DoFs other than the interfac

27、e DoFs are included. 4.3 Units All numerical input and output data shall be expressed in SI. Acceleration may be expressed in g, where g = 9,81 m/s2. Use of units other than those of SI is an exception that shall be submitted for the approval of the LSP. 5 General requirements 5.1 Modelling codes Th

28、e software (name and version) and the type of finite elements used for the modelling of the PL shall be indicated. The condensation procedure applied to the original dynamic model shall be described. 5.2 Co-ordinate systems A reference co-ordinate system for the PL model shall be defined. A drawing

29、of the PL ensemble with its co-ordinate system shall be included in the written report. BS ISO 14954:20054 The orientation of the PL axes with respect to the LV shall be defined by the LSP, based on compliance with requirements of clearance between PL and LV structures, on pad access to the PL, and

30、on mechanical and electrical interfaces as stipulated in the ICD. The same reference system shall be used for the geometrical description of the PL and for the definition of the DoFs in the mass and stiffness matrices. The axis system shall be cartesian. A local co-ordinate system may be used but sh

31、all be clearly defined. For interfaces, all reference shall be made to the reference co-ordinate system. 5.3 Theoretical aspects for modelling 5.3.1 General modelling The model shall describe the complete, dynamic, three-dimensional PL behaviour in free-free conditions and also clamped at its interf

32、ace with the launch vehicle. The model shall be representative up to a frequency specified by the LSP. 5.3.2 Liquid modelling If the payload contains significant liquid propellant mass, the model shall describe the slosh motions of these liquids, neglecting the surface tension and assuming that the

33、equilibrium surface is perpendicular to the liquids quasi-static net acceleration vector, when required by the LSP. The effects of fluid-structure interaction shall be taken into account in the prescribed frequency range. Typical values of quasi-static acceleration shall be provided by the LSP for l

34、oading cases to be considered. 5.3.3 Damping modelling Damping is usually based on approximations derived from engineering judgement and tests. It may be defined at the PL level, in which case a PL damping matrix shall be a part of the mathematical model. Damping may be defined at the system level b

35、y agreement between PLC and LSP, in which case no damping matrix is required. However, if necessary, the dependence of damping on frequency may be provided. 5.3.4 Interface modelling When the interface between the PL and the LV may be considered rigid, as approved by both the PLC and the LSP, the in

36、terface can be condensed to one node with six DoFs. Modelling of the PL-LV interface shall require greater accuracy when the flexibility of the interface might induce higher loads on the PL. This issue shall be discussed by both parties prior to the preliminary coupled analysis cycle. BS ISO 14954:2

37、00556 Condensation methods 6.1 Condensed physical model 6.1.1 General The choice of method of condensation is left to the discretion of the writer of the model. The condensed model shall be compliant with requirements given in Clause 7. The nodal points and DoF shall be defined as in 6.1.2. 6.1.2 Re

38、quirements 6.1.2.1 Unless otherwise specified, each physical nodal point of the interface shall have six DoFs in the reference co-ordinate system: TX= DoF 1, TY= DoF 2, TZ= DoF 3, RX= DoF 4, RY= DoF 5, RZ= DoF 6 where T is translation, R is rotation and X, Y, Z are the axes. 6.1.2.2 The DoFs shall b

39、e ordered in the matrices first according to the numbering of the nodes and second according to the numbering of the DoFs as listed in 6.1.2.1. 6.1.2.3 A local co-ordinate system may be used but shall be defined. In general, local co-ordinates are excluded for the interface DoFs. 6.1.2.4 Nodal point

40、 co-ordinates shall be expressed in the reference system of the PL. 6.1.2.5 As a result of these rules, the mass, stiffness and damping matrices may have a size less than 6N 6N, where N is the number of nodal points. 6.1.2.6 The OTMs may be supplied with related user instructions. The output paramet

41、ers shall be linearly dependent on the acceleration and/or displacement of nodal points. Thus, the OTMs are likely to have the same number of columns as the stiffness and mass matrices and P rows, where P is the number of output parameters. 6.2 Modal model 6.2.1 General The dynamic behaviour of the

42、PL shall be described by the reduced stiffness, mass and damping matrices, relative to the elastic modes (modal co-ordinates, k) and the interface nodes (the interface DoF, qj). This size of the stiffness and mass matrices (and the damping matrix if provided) is Q rows Q columns, such that Q = Ql+ Q

43、mwhere: Ql= number of degrees of freedom of the interface Qm= number of elastic modes BS ISO 14954:20056 6.2.2 Requirements 6.2.2.1 Unless otherwise specified, each physical nodal point of the interface shall have six DoFs in the reference co-ordinate system: TX= DoF 1, TY= DoF 2, TZ= DoF 3, RX= DoF

44、 4, RY= DoF 5, RZ= DoF 6 where T is translation, R is rotation and X, Y, Z are the axes. 6.2.2.2 The DoFs shall be ordered in the matrices first according to the numbering of the nodes and second according to the numbering of the DoFs as listed in 6.2.2.1. The modal DoFs shall be numbered differentl

45、y from the interface nodes because they are considered to have only one degree of freedom. The modal DoFs shall be ordered in the matrices according to the numbering of the modes. 6.2.2.3 Local co-ordinate systems may be used but shall be defined. In general, local co-ordinates are excluded for the

46、interface DoFs. 6.2.2.4 Nodal point co-ordinates shall be expressed in the reference system of the PL. 6.2.2.5 The OTMs shall be delivered in order to reconstitute loads, accelerations and displacements of nodes and elements that will allow a verification of the payload design. OTMs shall be separat

47、ed according to the type of output: kajqq= Awhere A is the acceleration transformation matrix (ATM); kdjqq= Dwhere D is the displacement transformation matrix (DTM); kkj j12qq =+ FL Lwhere L1 and L2 are the load transformation matrices (LTM1 and LTM2). The size of these matrices is P rows Q columns,

48、 where Q is defined in 6.2.1 and represents the size of the mass or stiffness matrix, and P is the number of output transformation parameters. NOTE P is not necessarily the same for each type of matrix. BS ISO 14954:20057For the modal model, if a damping matrix is provided it shall be defined as fol

49、lows: damping relative to interface nodes shall be assumed to be 0, or shall be defined by agreement between LSP and PLC; damping relative to the elastic modes shall be modal damping. 6.3 Hybrid model 6.3.1 General A hybrid model is an extended modal model with more physical DoFs than those solely for the interface. Its use is the same as for the modal model. The dynamic behaviour of the PL shall be described by the reduced stiffness, mass and damping matrices, relative to the