1. Introduction about Machine Design I
Section I
Introduction about Machine Design I

2. Talking Points What is the meaning of design?
Classifications of design
Mechanical engineering design?
Phases of design
Design considerations
Design factor of safety
Examples of mechanical equipments
Units

3. What is the Meaning of Design?
The formulation of plan for the satisfaction of a human need. Sometime the particular need to be satisfied is well defined, and sometime it is not; thus, a lot of thought and effort is necessary to understand the particular need, clearly.

4. Classifications of Design
Clothing design
Interior design
Highway design
Landscape design
Building design
Ship design
Bridge design
Computer-aided design
Heating system design
Machine design
Engineering design
Process design
Etc…

5. Mechanical Engineering Design?
The design of things and systems of a mechanical nature--machines, products, structures, devices, and instruments.
Mechanical design utilizes mathematics, physics (kinematics, statics, dynamics), material science, and the engineering mechanics science.

6. Phases of Design
The recognition of a need and a statement of this need in general terms. This defines the problem.
The consideration of different schemes for solving the problem and the selection of one to be investigated in more detail. This phase includes a feasibility studies, backed up by special research if necessary.
A preliminary design of the machine, structure, system, or process selected. This establishes broad overall features and makes it possible to write specifications for major components.
Design of all components and preparation of all necessary drawings and detail specifications.

7. Design Considerations
Strength
Reliability
Thermal properties
Corrosion
Wear
Friction
Processing
Utility
Cost
Safety
Weight
Life
Noise
Styling
Shape
Size
Flexibility
Control
Stiffness
Surface finish
Lubrication
Maintenance
Volume

8. Design Factor of Safety
The ratio of the component strength to the working or allowable stress.
The “strength” can be anything the designer chooses it to be. It should often be the yield strength, the ultimate strength, the fatigue strength…etc. It is a material property; while the working stress is the safe stress, which is allowed to be undertaken by the material in design.
For structural steel work, nd is taken 2.0 to 2.5; but in case of cast iron, concrete, wood, nd is taken as 4.0 to 6.0.

9. Examples of Some Mechanical Equipments
Chainsaw

10. Tractor with front-end-loader attachment
Examples of Some Mechanical Equipments – Cont.
Tractor with front-end-loader attachment
Aircraft landing gear
Industrial crane

11. Examples of Some Mechanical Equipments – Cont.
Reverse
Turbo Charger
Engine

12. Units