Transcript ME 303 PRINCIPLES OF CAE

ME 303 PRINCIPLES OF
CAE
ASST.PROF.DR.HASAN HACIŞEVKİ
Reverse Engineering:
What is Reverse Engineering?
 It is a systematic methodology
for analyzing the design of an
existing device or system,
either as an approach to study
the design or as a
prerequisite for re-design.
Reverse Engineering helps you to:
Develop a systematic approach
to thinking about the engineering
design of devices and systems
Acquire a mental data bank of
mechanical design solutions
Levels of Analysis in
Reverse Engineering
System-Wide Analysis
Subsystem Dissection Analysis
Individual Component Analysis
System-Wide Analysis
Customer Requirements
Engineering Requirements
Functional Specifications
Prediction of Subsystems and
Components
Subsystem Dissection Analysis
Document Disassembly
Define Subsystems
Determine Subsystem Functional
Specifications
Determine Subsystem
Physical/Mathematical Principles
Individual Component Analysis
Repeat Dissection Steps to Individual
Component
Define Component Material Selection and
Fabrication Process
Suggest Alternative Designs, Systems,
Components, and Materials
Example: Ten-Speed Bicycle
Customer's Perspective:
Provide transportation at moderate speeds, with
reasonable comfort, safety, and reliability, without
excessive effort, and at an affordable cost.
Engineer's Perspective:
Transportation of one individual and cargo weighing up
to XX pounds, dimensions not to exceed A x B x C,
with max speed up to YY mph on level or concrete
pavement, sustainable speed of ZZ mph for up to 3
hours, etc.
Functional Requirements
 Required Speed: affected by weight, gearing, tire size,
tire design, frame design, streamlining.
 Controllability: affected by handle bar position,
dimensions, brake grip design, front tube angle
 Safety:
Braking Capability affected by brake materials and
design.
Tire Puncture affected by tire materials, tire
construction, tire pressure.
Structure affected by frame material, thickness,
welding, frame design.
 Visibility: affected by finish, accessories, lights,
reflectors.
Functional Requirements (cont.)
 Ergonomics:
 Riding Comfort affected by seat shape, size, material,
positioning, adjustability, suspension, frame size.
 Steerability affected by handlebar location and shape,
dimensions.
 Braking affected by design of brake handgrip, calipers,
leverage.
 Power Delivery affected by frame size, crankset dimensions,
gearing, gearshift location, size, and type.
 Economics:
Ω Initial Cost affected by materials, complexity, number of parts,
manufacturing methods, sales volume.
Ω Maintenance Cost affected by tire materials, brake materials,
durability of components, complexity of subsystem design.
Dissection: Subsystem Level Bike
Define Subsystems
Frame
Seat
Steering, including handlebar and fork
Wheels, including hubs, spokes, rim, and tires
Power Input, including crankset and foot pedals
Power Transmission, including front and rear
deraileurs, gears, gear shift levers, and chain
Brakes, including brake pads, calipers, cables,
and handgrips
Example Reverse Engineering
Items
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Bathroom Scale
Bicycle Pump
Can Opener
Deadbolt Lock
Desktop Clamp
Doorknob Assembly
Flashlight
Hand Tool
Hose Nozzle
Kitchen Timer
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Model Car Drive Train
Pencil sharpener
Pepper Grinder
Piston Assembly
Pipe Clamp
Shower Massage Head
Sprinkler Head
Stapler
Toy Car
Toy Gun