Chapter 1 introduces mechanical engineering design, outlining its iterative and communication-intensive nature, while emphasizing the importance of functionality, safety, and reliability. It discusses the phases of the design process, design tools such as CAD software, and the responsibilities of design engineers regarding standards, codes, and economics. Key concepts such as stress, strength, uncertainties, design factors, and tolerances are also highlighted as essential considerations in the engineering design process.

1. [CHAPTER 1: INTRODUCTION TO MECHANICAL ENGINEERING DESIGN]
GIM-FC 2024
Seab Piseth | pisethseab@gmail.com | 011 70 48 25
Department of Industrial and Mechanical Engineering
Faculty of Electrical Engineering
Institute of Technology of Cambodia
MECHANICAL
CONSTRUCTION

2. Chapter 1: Introduction to Mechanical Engineering Design
Chapter Outline
 Design
 Mechanical Engineering
Design
 Phases and Interactions of the
Design
 Process Design Tools and
Resources
 The Design Engineer’s
Professional Responsibilities
 Standards and Codes
 Economics
 Safety and Product Liability
 Stress and Strength
 Uncertainty
 Design Factor and Factor
of Safety
 Reliability
 Dimensions and
Tolerances
 Units
 Calculations and
Significant Figures
 Design Topic
Interdependencies
 Power Transmission Case
Study Specifications

3. Chapter 1: Introduction to Mechanical Engineering Design
Design
 Design is an innovative and highly iterative process.
 Design is a communication-intensive activity in which both
words and pictures are used, and written and oral forms are
employed.
 The designer create of something having a physical reality,
then the product must be functional, safe, reliable,
competitive, usable, manufacturable, and marketable.

4. Chapter 1: Introduction to Mechanical Engineering Design
Design

5. Chapter 1: Introduction to Mechanical Engineering Design
Design

6. Chapter 1: Introduction to Mechanical Engineering Design
 Knowledge:
• Mechanics of solids and fluids, mass and
momentum transport, manufacturing
processes, electrical and information
theory
• Fluid flow, heat transfer, friction, energy
transport, material selection,
thermomechanical treatments, statistical
descriptions,
 Job Position:
• MVAC or MVAC: heating, ventilating, and
air-conditioning design
• Internal-combustion engine design,
turbomachinery design, and jet-engine
design
• Machine design, machine-element
design, machine-component design,
systems design, and fluid-power design
Mechanical Engineering Design

7. Chapter 1: Introduction to Mechanical Engineering Design
Phases and Interactions of the Design Process

8. Chapter 1: Introduction to Mechanical Engineering Design
Design Considerations

9. Chapter 1: Introduction to Mechanical Engineering Design
DESIGN TOOLS AND RESOURCES
 Computational Tools
• CAD CAM
• Autocad
• Solidworks
• Abaqus
 Acquiring Technical Information
• Libraries (community, university, and private) textbooks, monographs,
handbooks,
• Government sources. Departments of Defense, National Technical
Information Service; and National Institute for Standards and
Technology.
• Professional societies. American Society of Mechanical Engineers,
American Society for Testing and Materials, and American Welding
Society.
• Commercial vendors. Catalogs, technical literature, test data, samples,
and cost information.
• Internet. The computer network gateway to websites associated with
most of the categories listed above

10. Chapter 1: Introduction to Mechanical Engineering Design
• Understand the problem
• Identify the knowns
• Identify the unknowns and formulate the
solution strategy
• State all assumptions and decisions
• Analyze the problem
• Evaluate your solution
• Present your solution
THE DESIGN ENGINEER’S PROFESSIONAL RESPONSIBILITIES

11. Chapter 1: Introduction to Mechanical Engineering Design
STANDARDS AND CODES

12. Chapter 1: Introduction to Mechanical Engineering Design
STANDARDS AND CODES

13. Chapter 1: Introduction to Mechanical Engineering Design
 Standard Sizes
 Large Tolerances
 Breakeven Points
 Cost Estimates
ECONOMICS

14. Chapter 1: Introduction to Mechanical Engineering Design
SAFETY AND PRODUCT LIABILITY

15. Chapter 1: Introduction to Mechanical Engineering Design
STRESS AND STRENGTH
Strength is a property of a material or of a mechanical
element.

16. Chapter 1: Introduction to Mechanical Engineering Design
STRESS AND STRENGTH
Stress is a state property at a specific point within a body,
which is a function of load, geometry, temperature, and
manufacturing processing.

17. Chapter 1: Introduction to Mechanical Engineering Design
UNCERTAINTY

18. Chapter 1: Introduction to Mechanical Engineering Design
DESIGN FACTOR AND FACTOR OF SAFETY
- Design factor is the ratio of loss-of-function versus
allowable load
- The actual design factor may change as a result of
changes such as rounding up to a standard size for a cross
section or using off-the-shelf components with higher
ratings instead of employing what is calculated by using
the design factor. The factor is then referred to as the
factor of safety, n.
- Loss-off-function parameter= uncertainty (evaluate by
engineering) Ex. 20 %....
- Maximum load = the maximum load that is the applied on
the component or structure.

19. Chapter 1: Introduction to Mechanical Engineering Design
DESIGN FACTOR AND FACTOR OF SAFETY
OR

20. Chapter 1: Introduction to Mechanical Engineering Design
DESIGN FACTOR AND FACTOR OF SAFETY

21. Chapter 1: Introduction to Mechanical Engineering Design
DESIGN FACTOR AND FACTOR OF SAFETY

22. Chapter 1: Introduction to Mechanical Engineering Design
RELIABILITY

23. Chapter 1: Introduction to Mechanical Engineering Design
DIMENSIONS AND TOLERANCES
• Nominal size. The size we use in speaking of an element.
• Limits. The stated maximum and minimum dimensions.
• Tolerance. The difference between the two limits.
• Bilateral tolerance. The variation in both directions from the
basic dimension.
• Unilateral tolerance. The basic dimension is taken as one of
the limits, and variation is permitted in only one direction.
• Clearance. A general term that refers to the mating of
cylindrical parts such as a bolt and a hole.
• Interference. The opposite of clearance, for mating cylindrical
parts in which the internal member is larger than the external
member (e.g., press-fits).
• Allowance. The minimum stated clearance or the maximum
stated interference for mating parts.