ComputerAided_Design_Engineering_amp_Manufactur.pdf

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TABLE 1.1 earlier designs play an important role. Consideration of issues that influence the representation, organization, integration, and control of knowledge bases (which contain knowledge pertaining to FE modeling, FEA result interpretation, and design object modification) is an important task during the formulation of the system architecture for an Integrated CAD/FEM system. In this research work, we propose to use four knowledge bases—object modeling, finite element modeling, FEA result analysis, and evaluation knowledge base—for automating various tasks within the FEA procedure. The automation of the FEA process involves tasks that require very high-level intelligence (for decision making from abstract knowledge bases) together with lower-level tasks that can be processed by the successful deployment of various knowledge engineering techniques. The features offered by OOP environments would be very useful in achieving some of these objectives. System Architecture and Case Study Framework of an Integrated CAD/FEM system The developed framework of the Integrated CAD/FEM system is shown in Figure 1.2. The system essentially consists of an OOP-based CAD system (Concept Modeller), FEA packages (I-DEAS and ANSYS), an expert system shell (CLIPS), and necessary intelligent interface modules along with their knowledge base (KB) units (which contain FEA domain-specific knowledge). The aim of the Integrated CAD/FEM system is to provide an automated design environment for the design of engineering components. As shown in Figure 1.2, the designer specifies the initial design requirements through interaction with a conceptual design unit (CDU) built in the Concept Modeller system. The CDU is used to translate the specified initial design requirements into an appropriate object model of a component design with the help of a knowledge base, consisting of a library of design instances (i.e., previous design models) and links with domain-specific ‘‘experts” for simultaneous engineering. The domain-specific experts assist in establishing the preliminary design from a set of design alternatives created earlier from the knowledge © 2001 by CRC Press LLC Template of a Typical Design-Information Class ( define-part Design-Information-Class • inherit-from Information-class-mixin • Geometric-defn-object • Load-spec-Lx, Load-spec-Ly, Load-spec-Lz • Load-magnitude-Lx, Load-magnitude-Ly, Load-magnitude-Lz • Restraint-location-Lx, Restraint-location-Ly, Restraint-location-Lz, • Restraint-magnitude-Lx, Restraint-magnitude-Ly, Restraint-magnitude-Lz • Design-requirements • Design-requirement-bounds • FEM-Mesh-Model • FEM-Model ) / * Design-Information-Class definition * / / * Inherits the properties of this class * / / * Pointer to the geometric definition (B-Rep model) of the object * / / * List of specified load locations (point & pressure, fluxes, etc.) along the global x, y, & z axis direction * / / * List of specified load magnitudes (point & pressure, fluxes, etc.) along the global x, y & z axis direction * / / * List of specified restraint locations along the global x, y & z axis direction * / / * List of specified magnitudes of restraints along the global x, y & z axis direction * / / * Specification of design criteria and design variables, which are important from the standpoint of the design analysis to evaluate the design * / / * Acceptable range of parameter values under which the design could be termed satisfactory * / / * Pointer to the Finite Element Mesh of the object * / / * Pointer to the Finite Element Model of the object * /
FIGURE 1.2 base or the design instance library. These experts assist in pruning out the nonfeasible design alternatives during the preliminary design phase. The CDU helps capture the functional intent of the component design in the form of design rules, spatial and functional relationships between assemblies and parts, and part features. Since the object model and the underlying geometric entities are represented as individual objects (in OPP’s sense), subsequent changes in spatial relationships, assembly-part relationships, etc., can be easily undertaken without undesirably affecting the other parts in the assembly. At first, the Integrated CAD/FEM system builds an FEM model from the object model developed by the CDU for FEA in conjunction with an object modeling knowledge base based on the object’s shape, size, and other design conditions. The FEM knowledge base is used for making decisions regarding mesh generation for the object model and selection of appropriate element types and element sizes, depending on the particular FEA package to which the finite element (FE) model is to be transferred and the specified design analysis conditions. At present, an automated mesh generator (2-D and 3-D), based on the Delaunay triangulation scheme, is used for generating the FEM meshes. The automated mesh generator also provides the capability for checking the quality of the FE meshes. The user also has an option to take advantage of the automated meshgeneration capability of I-DEAS and ANSYS packages. After the FE meshes are completely generated for the FE model, the loading and boundary conditions are automatically specified on the FE model based on the initial design specifications. The whole FEM model would then be transferred as a single piece of information (input file) to the FEA package without any user interaction. The analysis of the FEM model in the FEA package would be controlled by means of a master control program running on the UNIX operating system. Currently, the master control program has been implemented using the CLOS-C foreign function call facility. Additionally, the control program also provides a restricted capability for window programming. The control program opens a window (X-window system) on the terminal screen where it executes the © 2001 by CRC Press LLC Framework of the Integrated CAD/FEM system.
Page 1 and 2: COMPUTER-AIDED DESIGN, ENGINEERING,
Page 3 and 4: Library of Congress Cataloging-in-P
Page 5 and 6: Editor Cornelius T. Leondes, B.S.,
Page 7 and 8: Chapter 1 Chapter 2 Chapter 3 Chapt
Page 9 and 10: the implementation of the IPD syste
Page 11 and 12: In our IPD system implementations,
Page 13: 2. Specification of analysis-specif
Page 17 and 18: FIGURE 1.4 System architecture of t
Page 19 and 20: of a beam is considered for FEA. Th
Page 21 and 22: FIGURE 1.7 through the control expe
Page 23 and 24: 2. machining facility (e.g., gang m
Page 25 and 26: from the FBDS. The user also specif
Page 27 and 28: Depending on the type of feature to
Page 29 and 30: TABLE 1.6 Tolerance synthesis is de
Page 31 and 32: FIGURE 1.12 Display of the NC tool
Page 33 and 34: component geometric entities and va
Page 35 and 36: FIGURE 1.14 The system architecture
Page 37 and 38: TABLE 1.10 User Input for the Toler
Page 39 and 40: TABLE 1.11 Tolerance Specifications
Page 41 and 42: 7. Z. Young and I. R. Groose. A rul
Page 43 and 44: FIGURE 2.1 Tool paths generated for
Page 45 and 46: FIGURE 2.2 sented by instances of f
Page 47 and 48: TABLE 2.1 A CAD-Generated Hole Conf
Page 49 and 50: FIGURE 2.6 mounted on the rotary ta
Page 51 and 52: FIGURE 2.8 fixture for the machinin
Page 53 and 54: FIGURE 2.10 or best-fit, or the cur
Page 55 and 56: FIGURE 2.11 Linear approximation of
Page 57 and 58: FIGURE 2.13 Circular approximation
Page 59 and 60: FIGURE 2.14(b) Circular approximati
Page 61 and 62: FIGURE 2.16 Types of biarcs. FIGURE
Page 63 and 64: FIGURE 2.18 Approximation of scanne
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FIGURE 2.20 A touch trigger probe c
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TABLE 2.4 Substitute Elements in CM
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FIGURE 2.21 CMM planning requiremen
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Product Model Representation for Co
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© 2001 by CRC Press LLC TABLE 2.5
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TABLE 2.7 Partial Listing of Dimens
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24. Makinouchi, S., Okamoto, M., an
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Bijan Shirinzadeh Monash University
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FIGURE 3.1 Trends in flexible manuf
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FIGURE 3.3 and constrain different
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Other Fixturing Techniques There ar
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FIGURE 3.6 contact point. The geome
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FIGURE 3.8 The vertical support fix
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and moments about the contact point
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een identified, the normals are use
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one of choosing the variables: such
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Fixture Module Location An importan
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FIGURE 3.15 Illustration of functio
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FIGURE 3.18 Minimum separation test
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direction) the face, respectively.
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FIGURE 3.21 Software structure for
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3.8 Conclusion A reconfigurable fix
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Heui Jae Pahk Seoul National Univer
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FIGURE 4.1(b) Conceptual framework
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4.3 Measurement Points Sampling and
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Surface S2 Measurement Path FIGURE
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FIGURE 4.4 Rough phase alignment ba
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deviation between the nominal CAD d
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FIGURE 4.6(a) Sum of squares distan
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FIGURE 4.7(c) Trailing edge. (c) th
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FIGURE 4.8(a) Profile tolerance of
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The calculated minimum form error i
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FIGURE 4.11(a) A typical mold havin
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FIGURE 4.11(d) Inspection results f
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FIGURE 4.12(c) Maximum deviation (p
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5.1 Introduction Developments in th
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process plan for a part (Figure 5.3
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FIGURE 5.5 leading to the developme
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the previously stored process plan
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FIGURE 5.7 Techniques of defining a
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Feature Recognition and Extraction
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in relation to another feature (e.g
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FIGURE 5.9 Framework for building a
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FIGURE 5.10 Process plan content.
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FIGURE 5.12 Schematic sketch of the
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Several techniques of defining a fe
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TABLE 5.1 Data Structure for Repres
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FIGURE 5.16 Classification of the t
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system to ensure that the part bein
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FIGURE 5.19 Graphical model of the
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TABLE 5.4 Data Structure for Repres
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FIGURE 5.20 Mapping between machini
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algorithms. (Some details of the pr
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FIGURE 5.24 An example rotational p
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FIGURE 5.26 Down_face-turn-up_face
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FIGURE 5.27 Procedure for machine t
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FIGURE 5.28 Determining the number
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DL is needed to be set only if the
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FIGURE 5.31 Operation sequencing co
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Cutting Tool Selection Selection of
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1. A tool is searched for in the da
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FIGURE 5.32 Inputs to optimization
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When these values are substituted,
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Usually, maximum and minimum speed
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FIGURE 5.33 Solution methodology.
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TABLE 5.6 Process Plan Internal Rep
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In a strict theoretical perspective
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18. Domazet, D. S. and Lu, S. C. Y,
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63. Prasad, A. V. S. R. K., Rao, P.
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CAD systems. The sample consists of
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learn to master the new system. An
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Although researchers appear to agre
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Link and Zmud28 found that organic
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Informal Training Informal CAD trai
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informal training programs, felt th
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6. C. A. Beatty, Tall Tales and Rea
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A.Y.C. Nee National University of S
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FIGURE 7.1 Planning, design, and ma
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A metal stamping can have the follo
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FIGURE 7.3 Strips used to notch out
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A Skeletal Approach for the Recogni
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These findings can be used to devel
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Semi-Direct Piloting In cases where
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a larger value, the die operations
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FIGURE 7.9 Symbolic relationship be
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FIGURE 7.11 The shape of the envelo
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TABLE 7.1 Schema for the Generation
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strong reasons to support a move to
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FIGURE 7.16 3-D CAD model of a part
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References Cheok, B.T. et al. (1994
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include the once forbidden generati
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A temporal matrix (T-Matrix) is pro
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FIGURE 8.1 A basic process. (From R
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FIGURE 8.4(a) Generate a new IG usi
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Note if the pair of nodes are both
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TABLE 8.1 Summary of the Rules Cond
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The correctness of these rules is e
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needs to show that after each full
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ule is violated, a warning should b
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Π1 Π3 Π4 FIGURE 8.8(a) After add
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
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A ik � ‘U’ and is in a cycle
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FIGURE 8.12(a) Add [p2 t7 p7 t8 p4]
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FIGURE 8.12(c) Add a token to p8 vi
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FIGURE 8.12(e) Add [p8 t9 p14 t10 p
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FIGURE 8.13 An example of rule TT.0
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FIGURE 8.14 A GPN model of a machin
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FIGURE 8.15(b) The first exclusive
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FIGURE 8.15(d) The last exclusive T
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FIGURE 8.15(f) After entering the a
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FIGURE 8.15(h) Completion of Compon
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FIGURE 8.15(j) Two PP-generations:
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FIGURE 8.15(l) The last exclusive T
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t1 t5 p1 p5 t6 (a) t2 t3 t4 2 2 p2
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FIGURE 8.17 An example of partial f
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Theorem 10: If pi → pk in a synth
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Note that control transitions are o
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t j than the lower at , it indicate
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• Programming logic and VLSI arra
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7. Chao, D. Y. and D. T. Wang, Appl
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53. Villaroel, J. L., J. Martinez,
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q u : the numerator of the least ra
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geometric modeling, engineering ana
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In dimension driven or parametric d
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FIGURE 9.3 configuration of bodies
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FIGURE 9.6 FIGURE 9.7 Geometric Int
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FIGURE 9.8 Intersection of degrees
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will introduce a way to propagate p
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Completeness of Dimensions Complete
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FIGURE 9.12 3-D constraints. © 200
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The distance constraint from pt �
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therefore: Now merge the lists and
Page 329 and 330:
Quantity analysis methods have the
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y a revolute joint. By selecting al
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