Group 9 4/26/05Ch. 38 Computer-Aided ManufacturingIntroductionManufacturing SystemsComputer-Integrated ManufacturingSlide 6CIM SubsystemsDatabaseBenefits of CIMComputer-Aided Design and EngineeringElements of CAD systemsCAD RepresentationsOctree representation38.5 Computer-Aided ManufacturingSlide 15Slide 1638.6 Computer-Aided Process Planning (CAPP)Slide 18Slide 1938.7 Computer Simulation of Manufacturing Processes and SystemsSlide 21Slide 22Chapter 40:40.1 Introduction40.1: Product DesignDesign ConsiderationsProduct design and quantity of materialDesign ProblemsSlide 2940.3: Product Quality and Life ExpectancyReturn on quality (ROQ):Life Expectancy of Products:40.4 Life-Cycle Assessment and Engineering; Sustainable ManufacturingSlide 34Slide 3540.5 Material Selection for ProductsSlide 37Shapes of Commercially available materials:Slide 39Reliability of material supplyCost of Materials and processingChapter 40.6-40.9Materials SubstitutionSlide 44Manufacturing Process CapabilitiesSlide 46Slide 47Process SelectionManufacturing Costs and Cost ReductionSlide 50Slide 51Slide 52BibliographyGroup 94/26/05Jason MaestasTim NgoStephen NeidigkDavid OrtegelCh. 38: Computer-Aided ManufacturingCh. 40: Product Design and Process Selection in a Competitive EnvironmentCh. 38 Computer-Aided Manufacturing• 38.1 Introduction• 38.2 Manufacturing Systems • 38.3 Computer-Integrated Manufacturing• 38.4 Computer-Aided Design and Engineering• 38.5 Computer-Aided Manufacturing• 38.6 Computer-Aided Process Planning• 38.7 Computer Simulation of Manufacturing Processes and Systems• 38.8 Group TechnologyIntroduction •Computer-aided design (CAD) assists the graphical descriptions of parts.•Computers are used in the direct control of manufacturing processes and computer-aided manufacturing.•Computers can also simulate manufacturing processes and systems.•Group technology approaches allow the rapid recovery of previous design and manufacturing experience and apply information to new situations in a straightforward manner.Manufacturing SystemsFactors:Supply and cost of raw materialsNational and global market changesImpact of constantly developing technologiesMachine-tool characteristics and performance Human behavior and performanceComputer-Integrated Manufacturing•Computerized integration of all aspects of product design, process planning, production, and distribution, as well as the management and operation of the whole manufacturing organization•The effectiveness of CIM critically depends on the use of a large-scale integrated communications system involving computers, machines, and their controls.Figure 39.1 A schematic illustration of a computer-integrated manufacturing system. Source: U. Rembold, et al., Computer-Integrated Manufacturing and Engineering. Addison-Wesley, 1993.Computer-IntegratedManufacturingCIM Subsystems•Business planning and support•Product design•Manufacturing process planning •Process automation and control•Production monitoring systemsFunctions •Business planning•Business executionDatabase•Product data: Part shape, dimensions, and specifications•Data management attributes: Revision level, and part number•Production data: Manufacturing processes used•Operational data: Scheduling, lot sizes, and assembly requirements•Resources data: Capital, machines, equipment, tooling, personnel, and their capabilitiesBenefits of CIM•Emphasis on product quality and uniformity, as implemented through better process control•Efficient use of materials, machinery, and personnel and major reduction of work-in-progress inventory, all of which improve productivity and lower product cost•Total control of the production, schedules, and management of the entire manufacturing operation•Responsiveness to shorter product life cycles, changing market demands, and global competitionComputer-Aided Design and Engineering•CAD involves the use of computers to create design drawings and product models through interactive computer graphics.•CAE allows several applications to share the information in the database. Applications include (a) finite-element analysis of stresses, strains, deflections, and temperature distribution in structures and load bearing members, (b) the generation, storage, and retrieval of data, and (c) the design of integrated circuits and various electronic devices.Elements of CAD systemsFigure 39.3 Various types of modeling for CAD• Geometric modelingCAD RepresentationsFigure 39.4 (a) Boundary representation of solids, showing the enclosing surfaces of the solid model and the generated solid model. (b) A solid model represented as compositions of solid primitives. (c) Three representations of the same part by CAD. Source: P. Ranky.Octree representationFigure 39.5 The octree representation of a solid object. Any volume can be broken down into octants, which are then identified as solid, void, or partially filled. Shown is two-dimensional version, or quadtree, for representation of shapes in a plane.38.5 Computer-Aided Manufacturing•Computer-aided manufacturing (CAM):–The use of computers to assist in all phases of manufacturing.•CAD/CAM systems: –Features: •Information can be transferred from the design stage into the stage of planning for manufacture without the need to reenter the data on part geometry manually. •Database developed during CAD is stored and processed further by CAM into the necessary data and instructions for operating and controlling production machinery, material-handling equipment, and automated testing and inspection for product quality. •Has the capability to describe the tool path in machine operations to check for possible tool collisions with clamps, fixtures, or other interferences visually.- Reduces design effort, tryout, and prototype work and significantly reduces manufacturing costs and improves productivity. •Benefits of CAD/CAM- Example: the two-engine Boeing 777 passenger airplane.- Designed by computer (paperless design) with 2000 workstations linked to eight computer.- Developed from CAD/CAM software , and no prototypes or mockups were built.- Cost for this development was $6 billion.–Applications of CAD/CAM systems:•Programming for numerical control and industrial robots.•Design of dies and molds for casting.•Dies for metalworking operations.•Design of tooling and fixtures and EDM electrodes.•Quality control and inspection.•Process planning and