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Chapter 1: Introduction - Coggle Diagram
Chapter 1: Introduction
CAD/CAM are widely used in engineering practice:
- Drafting
- Design
- Simulation
- Analysis
Role of computer in manufacturing:
- Monitor and control manufacturing process
- Manufacturing support applications
Types of CAD:
- CAD - computer aided design
- CADD - computer aided design and drafting
- CAE - computer aided engineering
- CAM - computer aided manufacturing
- CAPP - computer aided process planning
- CATD - computer aided tool design
- CAP - computer aided planning
Computer aided environment in manufacturing:
- Business Data Processing System
- CAD
- CAM
- Manufacturing systems
What is CAD?
- the use of IT in design process
- consists of IT hardware, specialized software
- make use of graphics for product representation
Role of CAD
- provide accurately generated and easily modifiable graphical representation of the product
Product engineering
- product functions
- product specifications
- conceptual design
- simulation
- strength
Design process stages
- Problem identification and identification of need
- Problem definition and conceptualization
- Geometrical modelling and spatial analysis
- Engineering analysis and optimisation
- Prototype development
- Manufacturing process development
- Manufacturing implementation
Advantages of CAD:
- Faster and accurate
- Can be edited
- Accurately calculate geometric properties
What is CAM?
- use of software to control machine tools
- use of computer to assist in all operations of manufacturing plant, planning, management, transportation, storage
eg. Mass production - automobiles, batch production - industrial machines, job shop production - prototypes
How it works?
- CAD geometry is transferred to a CAM system using data exchange file and used directly for manufacturing planning
- tool paths for computer numerically controlled (CNC) machine to machine parts can be generated from CAD
Manufacturing engineering:
- Process planning
- Process sheets
- Route sheets
- Tooling
- Cutting tools
- Jigs and fixtures
- Bill of Materials
Advantages of CAM:
- Greater design freedom
- Increased productivity
- Greater operating flexibility
- Improved reliability
What is CAE?
- use of IT for supporting engineers in analysis, simulation, design, manufacture
Areas of CAE:
- Finite element analysis (FEA)
- Computational fluid dynamics (CFD)
- Kinematics
- Mechanical event simulation (MES)
Advantages of CAE:
- Reduce product development cost n time
- Precise analysis and simulation
- early prediction of results
2D drafting tools
- Earliest CAD systems
- Replace traditional design on drawing board
Advantages:
- Provide significant productivity improvements
Disadvantages:
- Difficult to represent 3D shapes
3D wireframe
- can represent design in 3D
- allow to view design from any viewpoint
Limitations:
- no understanding of objects properties
- cannot represent the shape of the object faces between edges
- incomplete and ambiguous
- unable to provide area or volume information
Surface modelling
- completely define external shape of an object
- created by fitting smooth skin through a wireframe
Advantages:
- modelling complex freeform shapes
- provide excellent visualization of geometry
Limitations:
- only define external shapes but not internal
- unable to specify surface connectivity
Solid modelling
- the most complete and accurate CAD representation
- represents external and internal structure of the part
Advantages:
- solid models of complex freeform shapes are created using a combination of solid and surface
- can directly used for manufacturing, finite element, dynamic analysis
Limitations:
- can be extremely difficult to define
-
Kinematics analysis:
- analyses movement of mechanism from CAD assembly model
- joints are applied between different parts in the assembly
- can be used to evaluate motion of the motion of the mechanism and investigate potential locks or clashes
Finite element analysis (FEA)
- perform stress analysis to predict structural strength of a component
Engineering approach
- Sequential approach
- allows company to keep tight control over product development
- disadvantages-disciplines later in design process do not see the design until it is well developed, when potential problem may be costly to resolve
- Concurrent engineering n Integrated Product development
- method of designing and developing products, with different stages run simultaneous
Sequential product development process:
- Design
- Analysis
- Prototyping
- Process planning
- Logistics n support
- Manufacturing
- Manufacturing planning
Concurrent engineering product development process:
- Manufacturing
- Testing
- Customers
- Design
- Product support
- Suppliers
- Quality
- Marketing
All above into Product development