The document outlines the curriculum for a mechanical engineering design course, focusing on design principles, materials, stress and strength analysis, and the iterative nature of the design process. It emphasizes the importance of creativity, communication, and considerations such as functionality, safety, and marketability in engineering design. Additionally, it discusses the tools and methodologies involved in achieving optimal engineering solutions.

1. Pichet PINIT
1st teaching
Introduction to Mechanical Engineering Design
MTE 427 Machine Design

2. What will we learn in this course?
Introduction to Mechanical Engineering Design
Engineering Materials (short version)
Load and Stress Analysis
Deflection and Stiffness
Failure Theories for Static and Dynamic Loading
Design of Machine Elements
Shafts and Its Components
Screws and Fasteners
Mechanical Spring
Roller Contact Bearing
Gears (Spur, Helical, Bevel, and Worm Gears)
Flexible Mechanical Elements
Clutches, Breaks and Coupling

3. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication

4. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication
Given problem
Society’s needs

5. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication
Creativity
Information from society that needs
Designer’s knowledge related to such information
Coming up with something NEW

6. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication
Planning
Guide map to optimum solution based on such
something NEW

7. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication
Optimum solution
Solutions to such something NEW are infinite.
Make decision using Engineering Tools such as Mathematics,
Statistics, Computers, Graphics coupled with society’s information.
Optimum solution should be functional, safe, reliable, competitive,
usable, manufacturable, and marketable.

8. Introduction to Mechanical Engineering Design
What is design?
Design is the application of creativity to planning the optimum solution of
a given problem and the communication of that plan to others.
Given problem
Creativity
Planning
Optimum solution (the best solution for such problem at a time)
Communication
Communication
Tell other people (society) what you have done
Engineer’s success depends on communication skill (writing,
presenting, and speaking)

9. Introduction to Mechanical Engineering Design
Phases in design

10. Introduction to Mechanical Engineering Design
What is engineering design?
Design is the application of creativity to planning the optimum solution of
a given engineering problem and the communication of that plan to
others.
What is mechanical engineering design?
Design is the application of creativity to planning the optimum solution of
a given mechanical engineering problem and the communication of that
plan to others.
Focus on mechanical elements.
Focus on engineering problem.

11. Introduction to Mechanical Engineering Design
Why do we design?
To response such need
What are to be considered when designing?
Functionality, Safety, and Reliability
Strength and Stress
Deflection, Distortion, and Stiffness
Wear, Corrosion, Friction, Thermal, Surface, Noise, and Lubricant
Weight, Shape, Size and Life
Cost, Competition, and Marketability
Much more …

12. Introduction to Mechanical Engineering Design
Designers’ tools and resources
Computational Tools
Acquiring Technical Information
CAD/CAM/CAE
Libraries
Government sources
Professional societies (Standards: ISO, DIN, JIS, TIS, etc.)
Commercial vendors
Internet (Lots of information )

13. Introduction to Mechanical Engineering Design
Designing action steps
Understand the problem clearly
Identify what are known
Identify what are unknown and formulate solution strategy
State all assumptions and decisions
Analyze the problem with the solution strategy
Evaluate your solution (Is it sound good for real life?)
Present your solution
As seen in phase design, the design process are interactive and iterative.
Therefore, it may be necessary to repeat some or all of the above steps more
than once if less than satisfactory results are obtained.

14. Introduction to Mechanical Engineering Design
Economics and environment
Use standard sizes as possible (stock sizes).
Use large tolerances as possible.
Think of mass products (breakeven point).
Think hard of environmental effect.
Safety and product Liability
Manufacturer and designer always take responsibility no matter how
long is the life of a product.
Be careful of excessive promises
Be sure to provide adequate warning and instruction
Designer should always review, test, and control the quality of a product.

15. Introduction to Mechanical Engineering Design
Stress and strength
Strength is a build-in or inherent property of a material used to
manufacture a product.
Stress is an induced property of a product under a service.
Depending on the choice, the treatment, and the processing
of the material
Depending on the external load applied on the product, geometry,
temperature, etc.
Obtaining by testing (tension test, torsion test, etc.)
Obtaining by analyzing (Mechanics of Materials, Theory of Elasticity,
etc.)

16. Introduction to Mechanical Engineering Design
Uncertainty concerning stress and strength
Composition of material and effect of variation on properties (Isotropic,
anisotropic, orthotropic materials)
Variation on properties for different places or stocks
Effect of assemblies
Intensity and distribution of loading
Validity of mathematical models used to represent reality (do not forget
your assumptions when making analysis)
Stress concentration
Influence of time (time edge effect, creep)
Effect of corrosion and wear
Much more …
Designers themselves

17. Introduction to Mechanical Engineering Design
Design factor and factor of safety
How to deal with such uncertainties? Use a design factor.
The design factor is defined as
(1-1)
(1-2)
The parameter can be load, stress, deflection, etc. If the parameter is
load, the maximum allowable load is, then,
Ex 1.1

18. Introduction to Mechanical Engineering Design
After the design completed, the actual design factor may change as a
result of changes such as rounding up to a standard size for cross
section or using off-the-shelf components with higher ratings instead of
using what is calculated by the design factor. The factor, now, refers to as
the factor of safety, .
n
Factor of safety has the same definition as the design factor, but it
generally differs numerically.
Generally, .
n  1.3
Design factor and factor of safety

19. Introduction to Mechanical Engineering Design
Design factor and factor of safety
Stress may not vary linearly with load, using load as the loss-of-
function parameter may not be acceptable. The best way is to use the
design factor in terms of a stress and a relevant strength. Then,
(1-3)
The stress and strength terms must be of the same type and unit.
Ex 1.2

20. Introduction to Mechanical Engineering Design
Units
Use SI unit system (see more details by yourself).
Some useful rules for number:
1924 or 1 924 but not 1,924
0.1924 or 0.192 4 but not 0.192,4 (Decimal point should always be
preceded by a zero for number less than unity.)
192 423.618 50 but not 192,423.61850
Use prefixes for large and small numbers of possible.
Use the right symbols (k means kilo not K)

21. Introduction to Mechanical Engineering Design
Calculations and significant figures
Ex. 706, 3.14, and 0.002 19 have three significant figures.
The number of significant figures is usually inferred by the number of
figures given (except for leading zeros) showing the accuracy of a
measurement of physical parameters.
In engineering work, report your results with three or four significant
figures.
Use scientific notation to clarify the accuracy.
91 600 should be 91.6  103 or 91.60  103.
Never report a number of significant figures of a calculation any
greater than the smallest number of significant figures used for the
calculation.
Make all calculations to the greatest accuracy possible and report the
results within the accuracy of the given input.

22. Introduction to Mechanical Engineering Design
Be Professional
Be ethical people (know what is
right and wrong, what should
and shouldn't do.)

23. Introduction to Mechanical Engineering Design
Assignment
Read the text book on Load and Stress Analysis.

24. Introduction to Mechanical Engineering Design
Phases in design (just a copy slide)
Identification of need
Definition of problem
Synthesis or conceptual design
Analysis and optimization
Evaluation
Presentation
Iteration process