1. Chapter 2 Principles of Machinery Design
Key Terms:
strength
rigidity
failure mode
criterion
stress
allowable
factor of safety

2. Outlines Fundamental Requirements for Machinery Design
Failure Modes of Mechanical Components
Design requirements for Mechanical Components
General Criteria for Component Design

3. 2.1 Fundamental Requirements for Machinery Design
Functional Requirements
Safety and Environment Requirements
Reliability Requirements
Economic Requirements
Other Specific Requirements

4. 2.2 Failure Modes of Mechanical Components

5. 1、Fracture
2、Plastic Deformation & Elastic Deformation
3、Surface Damage:
Wear
Corrosion
Pitting
Glue
4、Abnormal Operational Condition:
Slip 打滑

6. fracture

7. plastic deformation

8. glue

9. Pitting

10. wear

11. 2.3 Design Requirements for Mechanical Component
Design for Safety
1) strength 2) rigidity 3) working life
Design for manufacturability
Design for Costs
Design for Reliability

12. 2.4 General Criteria for Component Design
Strength Criterion
Rigidity Criterion
Wear Criterion

13. Dynamic Criterion
Reliability Criterion
Safety Factor

14. 2.5 Methods of the Machinery Design
Traditional Design Methods
Theoretical Design
Empirical Design
Model Design

15. Modern Design Methods
CAD (computer–aided design)
FEM (finite element method)
OD (optimization design)
RD (reliability design)

16. 2.6 Materials in Machinery Design
Carbon steels
Alloy steels
Cast irons
Copper、Aluminum
Plastics
Composite materials

17. 2.7 Standardization in Machinery Design
Benefits:
• Ensure interchangeability of components;
• Permit convenient manufacture with standard machines and tooling.

18. Classification:
ISO GB QB

19. The end Thanks!