1 書名： Essentials of Mechanical Engineering Design, 1/E 作者： Shigey Mischke Budynas 書號： MX0398

2 1-1 Design To design is either formulate a plan for the satisfaction of a specified need or to solve a problem.

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6 Design consideration 1.Functionality 2.Strength/stress 3.Distortion/deflection/stiff ness 4.Wear 5.Corrosion 6.Safety 7.Reliability 8.Manufacturability 9.Utility 10.Cost 11.Friction 12. Weight 13.Life 14. Noise 15. Styling 16. Shape 17. Size 18. Control 19. Thermal properties 20. Surface 21. Lubrication 22. Marketability 23. Maintenance 24. Volume 25. Liability 26. remanufacturing/resource recovery

7 1-4 Design tool and resources CAD CAE MathCAD

8 1-5 The design engineer’s Professional responsibility Communication skill Responsible : To give the utmost performance To participate in none but honest enterprise To live and work according to the laws of man and the highest standards of professional conduct To place service before profit, the honor and standing of the profession before personal advantage, and the public welfare above all other considerations.

9 1-6 Codes and Standards Code is a set of specifications for the analysis, design, manufacture and construction of something. Standard is a set of specification for parts, materials, or process intended to achieve uniformity, efficiency and specified quality.

10 Standard size Large tolerance Breakeven points Cost estimates

Safety and Produce liability Any article is liable for any damage and harm that results because of a defect. Keep a record Transfer or seek another position

The Adequacy Assessment What strength applied? What stress applied? Which set of stress and strength is most revealing of functional integrity, which location or locations are critical? How accuracy are strength and stress known? How much of a difference between stress and strength is enough?

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17 Prefer units SI mm, kN, kg, Prefer number:

18 The ISO has defined four basic series of preferred numbers: R5: 10, 16, 25, 40, 63, 100. R10: 10, 12.5, 16, 20, 25, 31.5, 40, 50, 63, 80, 100. R20: 10, , 14, 16, 18, 20, 22.4, 25, 28, 31.5, 35.5, 40, 45, 50, 56, 63, 71, 80, 90, 100. R40: 10, 10.6, 11.2, 11.8, 12.5, 13.2, 14, 15, 16, 17, 18, 19, 20, 21.2, 22.4, 23.6, 25, 26.5, 28, 30, 31.5, 33.5, 35.5, 37.5, 40, 42.5, 45, 47.5, 50, 53, 56, 60, 63, 67, 71, 75, 80, 85, 90, 95, 100. An even more rounded series is indicated by putting two prime marks after the R: R 〃 5: 10, 15, 25, 40, 60, 100. R 〃 10:10, 12, 15, 20, 25, 30, 40, 50, 60, 80, 100. R 〃 20:10, 11, 12, 14, 16, 18, 20, 22, 25, 28, 30, 35, 40, 45, 50, 50, 55, 60, 70, 80, 90, 100.

Calculations and Significant Figures Usually three or four figures are necessary for engineering accuracy 91.6mm 91.60mm