The important issue of mechanical assemblies has been a subject of intense research over the past several years. Most electromechanical products are assemblies of several components, for various technical as well as economic reasons. This paper provides an object-oriented definition of an assembly model called the Open Assembly Model (OAM) and defines an extension to the NIST Core Product Model (NIST-CPM). The assembly model represents the function, form, and behavior of the assembly and defines both a system level conceptual model and associated hierarchical relationships. The model provides a way for tolerance representation and propagation, kinematics representation, and engineering analysis at the system level. The assembly model is open so as to enable plug-and-play with various applications, such as analysis (FEM, tolerance, assembly), process planning, and virtual assembly (using VR techniques). With the advent of the Internet more and more products are designed and manufactured globally in a distributed and collaborative environment. The class structure defined in OAM can be used by designers to collaborate in such an environment. The proposed model includes both assembly as a concept and assembly as a data structure. For the latter it uses STEP. The OAM together with CPM can be used to capture the assembly evolution from the conceptual to the detailed design stages. It is expected that the proposed OAM will enhance the assembly information content in the STEP standard. A case study example is discussed to explain the Usecase analysis of the assembly model.

1.
Booch
,
G.
,
Rumbauch
,
J.
, and
Jacobson
,
I.
, 1997,
The Unified Modeling Language User Guide
,
Addison-Wesley
,
Reading
.
2.
ISO
, 1994, “
STEP ISO 10303-Industrial Automation Systems and Integration-Product Data Representation and Exchange-Part 44: Integrated Resources: Product Structure Configuration
,”
ISO
, Geneva, CH.
3.
Sugimura
,
N.
, 2002, “
ISO/CD 10303-109, Product Data Representation and Exchange: Integrated Application Resource: Kinematic and Geometric Constraints for Assembly Models
,”
ISO
, Geneva, CH.
4.
Shah
,
J. J.
, and
Mantyla
,
M.
, 1995,
Parametric and Feature-Based CAD/CAM: Concepts, Techniques, and Applications
,
Wiley-Interscience
,
NY
.
5.
Narahari
,
Y.
,
Sudarsan
,
R.
,
Lyons
,
K. W.
,
Duffey
,
M. R.
, and
Sriram
,
R. D.
, 1999, “
Design for Tolerance of Electro-Mechanical Assemblies: An Integrated Approach
,”
IEEE Trans. Rob. Autom.
1042-296X,
15
(
6
), pp.
1062
1079
.
6.
Sudarsan
,
R.
,
Roy
,
U.
,
Narahari
,
Y.
,
Sriram
,
R. D.
,
Lyons
,
K. W.
, and
N. Pramanik
,
N.
, 2000, “
Information Models for Design Tolerancing: From Conceptual to the Detail Design
,” Technical Report No. NISTIR 6524,
National Institute of Standards and Technology
, Gaithersburg, MD.
7.
Sriram
,
R. D.
, 1999, “
Standards for the Collaborative Design Enterprise-Response to OMG’s MfgDTF RFI#4
,” http://cgi.omg.org/docs/mfg/99-08-04.pdfhttp://cgi.omg.org/docs/mfg/99-08-04.pdf
8.
Fenves
,
J. S.
, 2001, “
A Core Product Model for Representing Design Information
,” Technical Report No. NISTIR 6736,
National Institute of Standards and Technology
, Gaithersburg, MD.
9.
Chang
,
E.
,
Li
,
X.
, and
Schmidt
,
L. C.
, 2000, “
The Need for Form, Function, and Behavior-Based Representations in Design
,” Technical Report, DATLab,
University of Maryland
.
10.
MOKA
. “
MOKA: A Framework for Structuring and Representing Engineering Knowledge
,” http://www.kbe. coventry.ac.uk/moka/miginfo.htmhttp://www.kbe. coventry.ac.uk/moka/miginfo.htm
11.
Stokes
,
M.
, ed., 2001,
Managing Engineering Knowledge: MOKA Methodology for Knowledge Based Engineering Applications
,
ASME
.
12.
Whitney
,
D. E.
, and
Mantripragada
,
R.
, 1998, “
The Datum Flow Chain: A Systematic Approach to Assembly Design and Modeling
,” in
ASME Design Engineering Technical Conferences and Computers in Engineering Conference
,
ASME
.
13.
Whitney
,
D. E.
, 2004,
Mechanical Assemblies: Their Design, Manufacture, and Role in Product Development
,
Oxford University Press
,
Oxford
.
14.
Lee
,
K.
, and
Gossard
,
D. C.
, 1985, “
A Hierarchical Data Structure for Representing Assemblies: Part 1
,”
CAD
0010-4485,
17
(
1
), pp.
15
19
.
15.
Van der Net
,
A.
, 1998, “
Designing and Manufacturing Assemblies
,” Ph.D. thesis, Eindhoven University of Technology.
16.
Noort
,
A.
,
Hoek
,
G. F. M.
, and
Bronsvoort
,
W. F.
, 2002, “
Integrating Part and Assembly Modeling
,”
CAD
0010-4485,
34
(
12
), pp.
899
912
.
17.
Callahan
,
S.
, and
Heisserman
,
J.
, 1997, “
A Product Representation to Support Process Automation
,” in
M. J.
Pratt
,
R. D.
Sriram
, and
M. J.
Wozny
, eds.,
Product Modeling for Computer Integrated Design and Manufacture
,
Chapman and Hall
, pp.
285
296
.
18.
Shah
,
J. J.
, 1991, “
Assessment of Features Technology
,”
CAD
0010-4485,
23
(
5
), pp.
331
343
.
19.
Shah
,
J. J.
, and
Rogers
,
M. T.
, 1993, “
Assembly Modeling as an Extension of Feature-Based Design
,”
Res. Eng. Des.
0934-9839,
5
, pp.
218
237
.
20.
Van Holland
,
W.
, and
Bronsvoort
,
W. F.
, 2000, “
Assembly Features in Modeling and Planning
,”
Rob. Comput.-Integr. Manufact.
0736-5845,
16
(
4
), pp.
277
294
.
21.
Coma
,
O.
,
Mascle
,
C.
, and
Véron
,
P.
, 2003, “
Geometric and Form Feature Recognition Tools Applied to a Design for Assembly Methodology
,”
CAD
0010-4485,
35
(
13
), pp.
1193
1210
.
22.
Chan
,
C. K.
, and
Tan
,
S. T.
, 2003, “
Generating Assembly Features Onto Split Solid Models
,”
CAD
0010-4485,
35
(
14
), pp.
1315
1336
.
23.
ISO
, 1994, “
ISO 10303-1 Industrial Automation Systems and Integration-Product Data Representation and Exchange-Part 1: Overview and Fundamental Principles
,”
ISO
, Geneva, CH.
24.
ISO
, 2003, “
ISO 10303-108. Product Data Representation and Exchange: Integrated Application Resource: Parameterization and Constraints for Explicit Geometric Product Models
,”
ISO
, Geneva, CH.
25.
ISO
, 1996, “
ISO 10303-105. Industrial Automation Systems and Integration-Product Data Representation and Exchange-Part 105: Integrated Application Resource: Kinematics
,”
ISO
, Geneva, CH.
26.
Kandikjan
,
T.
,
Shah
,
J. J.
, and
Davidson
,
J. K.
, 2001, “
A Mechanism for Validating Dimensioning and Tolerancing Schemes in CAD Systems
,”
CAD
0010-4485,
33
(
10
), pp.
721
737
.
27.
Kemmerer
,
S.
, ed., 1999,
STEP: The Grand Experience
,
NIST Special Publication 939
,
National Institute of Standards and Technology
,
Gaithersburg, MD, USA
.
28.
Sudarsan
,
R.
,
Han
,
Y. H.
,
Feng
,
S. C.
,
Roy
,
U.
,
Wang
,
F.
,
Sriram
,
R. D.
, and
Lyons
,
K. W.
, 2003, “
Object-Oriented Representation of Electro-Mechanical Assemblies Using UML
,” Technical Report No. NISTIR 7057,
National Institute of Standards and Technology
, Gaithersburg, MD.
29.
Connacher
,
H.
,
Jayaram
,
S.
, and
Lyons
,
K. W.
, 1997, “
Virtual Assembly Using Virtual Reality Techniques
,”
CAD
0010-4485,
29
(
8
), pp.
575
584
.
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