1 / 16

An Overview of Design Process

An Overview of Design Process . Steven N. Kramer Nagi G. Naganathan MIME Department The University of Toledo. What is Design?. Involves the creation of a device, component, mechanical or other system, software program, or engineering process to meet a desired set of specifications.

rozene
Download Presentation

An Overview of Design Process

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. An Overview of Design Process Steven N. Kramer Nagi G. Naganathan MIME Department The University of Toledo

  2. What is Design? • Involves the creation of a device, component, mechanical or other system, software program, or engineering process to meet a desired set of specifications. • Occurs when human brain combines knowledge of facts and figures with creative abilities to synthesize. • Increasing in complexity -- Space shuttle more than 107 parts!

  3. Stages of Engineering Design Feedback & iterations can occur at any stage!

  4. Stage 1a: Why do it? Confront/ motivate Typical Forms • Letter to engineer • Memo from superior • Observation of troubles in plant • Staff conference Typical Features • Too much or too little information • No clear-cut goals/objectives • Objectives specified may not meet the REAL NEED!

  5. Stage 1b: Sources of Information • Technical journals • Government publications • Commercial catalogs • Internet • Engineer’s or client’s files & experience • Consultation with others, including those in different but related technologies.

  6. Stage 2a: Formulate problem • Recognition • What is the REAL NEED? • Drawbacks of current practice? • Do we need a new approach? • Can existing approach be improved by increasing capacity, longer life, or greater accuracy? • Definition • Necessary & desirable objectives -- performance, safety, purchase cost, assembly, disassembly, weight, size, maintenance cost, etc.

  7. Stage 2b: Prepare information & assumptions • Key dimensions based on practical and theoretical knowledge wherever possible. • Augment by assumptions where knowledge is lacking.

  8. Stage 3: Select Design Concepts DEVELOPMENT • List related fields & existing solutions in those fields. • List candidate solutions • List the features or functions essential to the product (not physical components). • For each feature or function, list the means by which it might be achieved. • Draw up a chart containing all possible sub-solutions • Sketch configurations

  9. How to identify candidate solutions? - Morphological chart • Example:Forklift truck • Identify functions/features: • Means of support which allows movement • Means of moving the vehicle • Means of steering the vehicle • Means of stopping the vehicle • Means of lifting loads • Location for operator.

  10. How to identify candidate solutions? - Morphological chart • Identify means for functions/features • Support: Wheels, track, air cushion, etc. • Propulsion: Driven wheels, air thrust, moving cable, etc. • Power: Electric, gas, diesel, propane • Transmission: Gears, belts, hydraulics, etc. • Steering: Turning wheels, rails, etc. • Stopping: Brakes, rev. thrust, ratchet • Lifting: Hydraulic ram, rack & pinion, screw, chain, rope hoist • Operator: Seated at front, rear, walking, remote control

  11. Concepts - Morphological chart

  12. Evaluation of a candidate concept • Is it simple? • Acceptable to maker and user? • Expressible clearly? • Up to date in materials & methods? • Does it satisfy the REAL NEED?

  13. Stage 4: Synthesize • To determine the values (size, shape, properties, etc.) of the essential parameters of a system or component.

  14. Stage 5: Abstracting analyzable model • Simplified physical version • Mechanical-electrical analogs • Models based on 1-D equivalence • Mathematical models • Free-body diagrams • Kinematic skeletal diagrams.

  15. Stage 6: Analyze, experiment & optimize • Analysis: • Kinematic-Dynamic • Loads -- Stress & strain • Energy balance • Economic • Prototype • Design of experiments • Optimize

  16. Stage 7: Present product to user & maker • Flow charts • Plant layouts and models • Specifications • General, subassembly, and detail drawings • Gant charts for realization of design • Economic tables & bar charts.

More Related