1、, AMERICAN NATIONAL STANDARD Symbols for Mechanical and Acoustical Elements as Used 0 In Schematic Diagrams ANSI Y32.18 - 1972 FOR CURRENT COMMITTEE PERSONNEL PLEASE SEE ASME MANUAL AS-I 1 SECRETARIAT INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS PUBL
2、ISHED BY THE AMERICAN S.OCIETY OF MECHANICAL ENGINEERS United Engineering Center 345 East 47th Street New York, N. Y. 1001 7 No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright 8, 197
3、2, by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS Printod in U.S.A. FOREWORD Ever increasing use has been made during recent decades of schematic diagrams in representing mechani- cal and acoustical systems. This development is a natural outgrowth of the same technique as was developed earlier for
4、electric networks. Such diagrams are important because of their usefulness in two connections. First, a mechanical or an acoustical system can be analyzed much more rapidly with a schematic diagram than without. Indeed, systematic methods have been developed in recent years which can generate correc
5、t descriptive equations for the system given its schematic diagram and specifications of the properties of each element in the system. Furthermore, the use of such methods tends to minimize blunders in analyses, such as wrong signs for terms, which even the most experienced analyst is apt to make fr
6、om time to time. Second, as an analyst gains experience with schematic diagrams he develops an insight into the character- istic performance of collections of interconnected elements. Thus he develops an ability to anticipate the performance of a system, at least in a qualitative way, based solely o
7、n a study of its schematic diagram. This is an attribute of schematic diagrams that is most useful, as was discovered earlier by electrical and elec- trical and electronics engineers. It is to be noted that each of the foregoing points concerns a determination of the performance of a system; i.e., a
8、n analysis of the system. It is not surprising, therefore, that schematic symbols are constructed primarily to make analyses easier and more straightforward. In recent years, however, there has developed a considerable interest in schematic diagrams in connection with the synthesis problem. From thi
9、s point of view one starts with a specification of the overall performance desired in a system. If some specifications are then assigned to the schematic diagram, such as the number of juri-ctions and branches in the diagram, it is conceivable that the constitutive equations for the elements can be
10、determined. Although techniques of this sort have not been worked out in detail as yet, they are receiving a lot of attention at the time of this writing and hold great promises for the future. Because this standard concerns a relatively new field, the Writing Group was forced to make some de- cisio
11、ns. The most important one concerned the question whether it is desirable to try to evolve some stand- ard symbols now rather than to wait a number of yearsin the hope that some fairly uniform practices m.?y evolve. It is recognized that standards are much easier to establish if a unanimity of opini
12、on exists. l3e Writing Group believed, however, that a significant contribution could be made to an evolving practice if some sort of a standard practice could be adopted now. No doubt, any user of this standard will find some things that he likes and some that he would like to see changed. Suggesti
13、ons for improvement based on experience gained in the use of this standard will always be welcome and should be mailed to the Secretary, American National Standards Committee Y32, in care of the ASME. This standard was prepared by a committee working under the auspices of the American National Stand
14、- ards Committee on Acoustics, S1, and the American National Standards Committee on Mechanical Shock and Vibration, S2. It was approved by the above American National Standards Committees and by American National Standards Committee Y32 on Graphic Symbols and Designations on November 23, 1971 when i
15、t was sent to American National Standard Institute for approval as an American National Standard. The ANSI approval was received on April 20, 1972 and it was designated ANSI Y32.18-1972. . Ill AMERICAN NATIONAL STANDARDS COMMITTEE Y32 GRAPHIC SYMBOLS AND DESIGNATIONS OFFICERS C. A. Fricke, Choirman
16、J. L. Fisher, Vice Choirmon - Mechanical W. L. Hewetson, Vice Choirman - Chemical and Process L. A. Meadows, Vice Choirman - Government Lioison C. R. Muller, Vice Choirman - Electricol 5. I. Sherr, Secretory COMMITTEE MEMBERS ACOUSTICAL SOCIETY OF AMERICA Laurence Batchelder, 983 Memorial Drive, Cam
17、bridge, Massachusetts 02138 H. F. Olson, R.C.A. Laboratories, Princeton, New Jersey AMERICAN CHEMICAL SOCIETY R. F. Schuerer, Linden, New Jersey AMERICAN GEAR MANUFACTURERS ASSOCIATION Gene L. Scott, American Gear Manufacturers Association, Washington, D.C. AMERICAN INSTITUTE OF CHEMICAL ENGINEERS J
18、. R. Couper, IJniversity of Arkansas, Fayetteville, Arkansas W. L. Hewetson, American Institute of Industrial Engineers, New York, New York 1. R. Goldstein, Newark College of Engineering, Newark, New Jersey AMERICAN INSTITUTE OF MINING, METALLURGICAL AND PETROLEUM ENGINEERS J. W. Worren, The Anacond
19、a Company, Butte, Montana AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS J. A. Basselman, American Society of Agricultural Engineers, St. Joseph, Michigan. P. L. Bellingel; Alternate, American Society of Agricultural Engineers, St. Joseph, Michigan AMERICAN SOCIELTY OF CIVIL ENGINEERS K. R. Jacobs, Geor
20、gia Institute of Technology, Atlanta, Georgia AMERICAN SOCIECTY FOR ENGINEERING EDUCATION 1. L. Hill, Illinois Institute of Technology, Chicago, Illinois J. G. McGuire, Texas A Schematic Diagram 4 4.5 Perfect Coupler 4 4.6 Multi-Terminal Element . 4 4.7 Supplementary Symbols . 5 5 5.1 General . 5 .
21、Description of Symbols 5 5.2 Symbols for Pure Inertances . 5 5.3 Symbols for Pure Compliance . 5 5.4 Symbols for Pure Dissipations 5 5.5 Symbols for Pure Sources for Excitatjons (Generators) . 5 5.6 Symbols for Perfect Couplers . 5 5.7 Symbols for General Elements . 5 5.8 Supplementary Symbols . 5 A
22、ppendix . General Information on Construction of Schematic Diagrams . 6 xi Intentionally left blank ANSI Y32.18-1972 AMERICAN NATIONAL STANDARD SYMBOLS FOR MECHANICAL AND ACOUSTICAL ELEMENTS AS USED IN SCHEMATIC DIAGRAMS 1. Scope This document presents standard symbols and definitions that may be us
23、ed in constructing schematic diagrams for mechanical and acoustical systems whose performances are describable by finite sets of scalar variables. The choice of symbols described herein is based upon the fol- lowing assumptions: a. A system can be divided conceptually into a finite set of elements e
24、ach of whose dynamical properties are known. b. To each such conceptual element there can be assigned a set of terminals. c. Symbols for the elements shall be inter- connected to form a schematic diagram for the whole system so that field equations shall be satisfied at every junction point and arou
25、nd every closed loop. The symbols which appear in this standard were evolved with the following principles in mind: a. It shall be possible to draw the symbols easily and quickly. b. The symbol shall be distinctive and where feasible shall suggest some well-known embodi- ment of the element in quest
26、ion. c. The symbols shall preferably have been used previously in the scientific literature. NOTE 1. Questions concerning the specific form for a so-called equivalent circuit of an electromechanical or any other type of mixed system are not within the scope of this standard. NOTE 2. An Appendix (not
27、 a part of this standard) provides background informa- tian on the use of the symbols in constructing schematic diagrams. 2. Terms Used in Connection with Schematic Diagrams The meanings to be attached to terms or ex- pressions as used in this standard are to be con- sistent with the definitions in
28、American National Standard Acoustical Terminology (ANSI S1.1-1960 or latest revision) and American National Standard Letter Symbols for Acoustics (ANSI Y10.11-1953 (R 1959), or latest revision). In addition, the following listed terms will be useful in schematic diagramming and therefore the section
29、s of this document where they appear are tabulated. Notations 3.8 Coding 3.2 Directivity of a Variable 3.6 Terminals 3.3 3. Characteristics of Schematic Diagrams and Symbols 3.1 General. The schematic symbols appear- ing in this standard contain the following types of information: a. Coding b. Termi
30、nals c. Directivity d. Labels e. Notations The first two types of information are always present; the latter three may or may not be necessary in any specific case. The criterion that is used to decide whether they shall or shall not be included in a schematic symbol is whether or not they are neede
31、d for clarity and complete- ness of information. 3.2 Coding. The coding is that portion of a symbol which by its configuration specifies the characteristics of the physical element which stands in one-to-one correspondence with the symbol. Thus the symbols corresponding to the rigid masses and acous
32、tical cavities will all have different codings. (See Subsection 4.4). 3.3 Terminals. The terminal is that portion of the symbol representing connection to adjoining elements or to points of physical access to the whole system. A terminal is represented by an 1 AMERICAN NATIONAL STANDARD GRAPHIC sYMB
33、OLS AND DESIGNATIONS ANSI Y32.18-1972 open circle joined to the coding by a line. (See Subsection 4.4). 3.4 Across Variables. Across variables de- scribe quan,tities which are observable or act on an element relative to a reference. 3.5 Through Variables. Through variables de- scribe quantities whic
34、h are observable or are transmitted continuously through an element. 3.6 Directivity. Directivity is a property as- sociated with a path connecting two terminals of the same element. It specifies either the reference terminal of the associated across variable or the direction. of propagation of the
35、corresponding through variable. In the former case a - sign is placed by the reference terminal and a + sign by the other terminal; in the second case an arrow- head is added to the line terminating on the reference node with the arrowhead pointing toward the reference node. (See Subsection 4.4). NO
36、TE: These two methods of indicating direc- tivity are not independent for one implies the! other. Thus it is not necessary or desirable to use both designations in the symbol for any element. 3.7 Labels. Labels are numbers or letter sym- bols placed beside or on the coding of an element. They are us
37、ed as needed to provide information to a user of the diagram of a system. (See Subsec- tion 4.4). 3.8 Notations. There will be certain items of information which will be needed in addition to the above symbol information in order to completely describe the system which corresponds to the diagram. Th
38、ese extra items of information may be added by a margin of the diagram and are called notations. Typical items that are contained in the notations are: a. Statements describing the coordinate sys- tems assigned to the system; b. Definitions of labels; c. Constraints imposed by perfect couplers. 4. G
39、eneral Symbols NOTE A: Letter notation labels identify modes of motion. NOTE 6: Sense of motion indicated by +,- or+. NOTE C: The exact meaning of the label must be given in notations for any non-linear . dissipative element. 4.1 Rectilinear Motion 4.1.1 lnertance +k-$ M See 4.7.2. 4.1.2 Compliance
40、4.1.3 Dissipation RhA See Note C. 4.1.4 Generator (across variable) 4.1.5 Generator (through variable) 2 AMERICAN NATIONAL STANDARD GRAPHIC SYMBOLS AND DESIGNATIONS 4.2 Rotary Motion 4.2.1 lnertance See 4.7.2. 4.2.2 Compliance CR 4.2.3 Dissipation RR See Note C. 4.2.4 Generator (across variable) ANS
41、I Y32.18-1972 4.3 Acoustical (Eulerian) 4.3.1 lnertancc MA 4.3.2 Compliance CA See 4.7.2. 4.3.3 Dissipation See Note C. 4.3.4 Generator (across variable) -+ 4.3.5 Generator (through variable) 4.2.5 Generator (through variable) 3 AMERICAN NATIONAL STANDARD GRAPHIC SYMBOLlS AND DESIGNATIONS ANSI Y32.1
42、8-1972 4.4 Typical Application; Schematic Diagram 4.5 Perfect Coupler 4.5.1 Direct Coupler Examples of notations: 1: UI = 1uj Ifi + fj = o* 4.5.2 Inverse Coupler n: fi = spj sui + uj = o* *Relation is redundant in that it can be inferred from the first relation and the fact that the ele- ment is a p
43、erfect coupler. It is helpful however to include it in the notations. NOTE 1: Although only two sections are shown in the above symbols, by exten- sion the element may include any finite number of sections. NVE 2 It is frequently the case that there are interconnections between the sections of a cou
44、pler. 4.6 Multi-terminal Element H defined in terms of the across variable a, and the corresponding through variables. 4 AMERICAN NATIONAL STANDARD GRAPHIC SYMBOLS AND DESIGNATIONS 4.7 Supplementary Symbols 4.7.1 Uncoded Line e 0 4.7.2 Reference Terminal 5. Description of Symbols 5.1 General. The st
45、andard symbols are listed in Section 4. General Symbols. . 5.2 Symbols for Pure Inertances. Symbols for a pure inertance are suggestive of rigid pieces of matter or a portion of fluid within a stationary pipe. The coding contains a solid circle at its centroid, suggesting that the element can be spe
46、cified precisely by considering only the motion of its center of mass and as if all forces were concentrated at this point. 5.3 Symbols -for Pure Compliance. The Sym- bols for pure compliance are suggestive of springs in the case of rectilinear and rotary motions and of a cavity in acoustical system
47、s. 5.4 Symbols for Pure Dissipations. The Sym- bols for pure dissipations are suggestive of a piston moving in a viscous oil, a disk spinning in a viscous oil, or a fluid being forced through a porous screen. 5.5 Symbols for Pure Sources of Excitations (Generators). The symbols given in Section 4 ar
48、e simple and obvious modifications of the symbols used for electrical sources so as to allow ready distinction between the two types of energy sources. It should be noted that only two types of generators have had widespread use in mechanical and acoustical systems. In one type the value of an acros
49、s variable is a specified function of the time; in the other a through variable is a specified function of the time. In either case the device has an inherent directivity so that their symbols must include this information. 5.6 Symbols for Perfect Couplers 5.6.1 General. A perfect coupler is a con- ceptual element which does not generate, store or dissipate energy, yet can transfer energy from ANSI Y32.18-1972 one part of a system to another. There are two types of couplers, the distinction being based on the nature of the constraints they impose. Symbols for perfect couplers are shown i
