Turbomachinery Laboratory at Hanyang University. Rotordynamics. Bearings. Seals. Dampers.

Hanyang University Department of Mechanical Engineering

Last revised: Apr. 28, 2024

DME3051: Mechanical Design

1. Class information
• Class Year and semester: 2023, SPRING semester
• Course No. : DME3051
• Course title: Mechanical Design
• Credit-Lecture Hour-Practice Training: 3.00-3.00-0.00
• Course outline: Two 90-minute lectures/week
• Organizing Department: Mechanical Engineering (ERICA)

2. Instructor information
• Name: Dr. Keun Ryu
• Department: Mechanical Design Engineering
• Email: kryu@hanyang.ac.kr
• Web: http://turbolab.hanyang.ac.kr/DME3051.html

• Office hours: By scheduled appointment (E-mail in advance required)
• About office hours: This is to encourage individual interaction between the students and the instructor. Students should prepare by organizing questions in advance.

3. Course objective
To provide the fundamental and practical theory and knowledge on design method, analysis and modeling of mechanical system, fluid film bearings, rolling element bearings, gears, springs, shaft and associated parts.

(Students will learn how to design the mechanical parts which are the basic elements for designing and manufacturing the mechanical system.)

4. Course Description (IC-PBL) :
Learn fundamental theory and knowledge on mechanical elements and design processes and methodologies for mechanical system design. Enhance understanding and design capability for shafts, keys, coupling, and flywheels with realistic design problems. Case studies will be provided throughout the course.

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* Note that this class follows the IC-PBL format.

The IC-PBL is an "industry-linked, problem-based, project course method" focused on the development of various capabilities required for future leaders of society.

5. Textbook
Fundamentals of Machine Component Design (7th Edition, Asia Edition)

https://m.hanbit.co.kr/store/books/book_view.html?p_code=B4947776485

https://www.wiley.com/en-kr/Fundamentals+of+Machine+Component+Design%2C+Asia+Edition%2C+7th+Edition-p-9781119644040

You can purchase the textbook at the on-campus bookstore (Tel: +82-31-400-4536)

6. Grading
IC-PBL Activity (30%=Weekly Report/Presentation 6%+Participation 9%+Literature Review 6%+Final Report/Presentation9%),Mid-term Exam (30%), Final Exam (30%), Attendance (10%).
* Weekly/Final Report/Presentation: Group 70% + Individual 30%
Attendance to the lectures is a must for success.

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** Template for weekly task plan: Your group presentation must include the contents in this report.

Ąć Before each weekly presentation, please turn in your team work (both weekly task plan and the PowerPoint) to Dr. Ryu.

7. One minute paper
At end of class, the instructor will request students to fill Ą°One Minute PaperĄą to establish their degree of understanding and address to questions or issues still unanswered. Please download the template.

8. Group Project: IC-PBL Subject

1) Problem statement (scenario): Demonstration of hydrodynamic (fluid film) bearings with large load carrying capacity

2) Objectives: Learn operating principles of hydrodynamic fluid film journal bearings

3) At the end of the semester (week 15), the final report and presentation must have the following outline and contents:

1) Introduction, 2) Literature review, 3) Project objective, 4) Project tasks, 5) Design procedure, 6) Engineering analysis and calculation, 7) Fabrication and building the test rig, 8) Demonstration and test procedure, 9) Experimental results, 10) Findings and discussions, 11) Comparison to predictions (calculation results), 12) Conclusions, 13) Lessons learned
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4) Rules for Group Formation and Weekly Presentation
- (Up to) 5 students/group
- Group presentation for group assignments: 8~10 minutes for each group, 2 minute for discussion
- Total #s of Slides: 8~12 pages
The weekly presentation must show the 1) Problem statement, 2) Goal, 3) Brief introduction, 3) Justification/Motivation, 4) Scope, 5) Tasks, 6) Methodology, and 7) Schedule for the project. Recall Template for weekly task plan.

5) Additional resources: IMPORTANT Ąć PLEASE study the following references before you ask very fundamental questions!

https://information.hanyang.ac.kr/#/eds/ebook/detail?id=978-1-118-63724-1 (Open full text, and then Search: "load carrying capacity")

https://information.hanyang.ac.kr/#/eds/ebook/detail?id=978-0-12-397047-3 (Open full text, and then Search: "4.5 JOURNAL BEARINGS")

https://information.hanyang.ac.kr/#/eds/ebook/detail?id=978-0-444-82366-3 (Open full text, and then Search: "load carrying capacity")

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6) Videos

Kingsbury Tilting Pad Hydrodynamic Air: https://youtu.be/EVjBeAzbUMI?si=eUtgiALgu1xoAZhM

The Self-Levitating Kingsbury Aerodynamic Bearing: https://youtu.be/HcVA-4mcXQQ?si=RWd80u2JEnlFEntG

Rayleigh Hydrodynamic Thrust Bearing: https://youtu.be/ed3uWxV2tXg?si=qhIKFEdeqk-8U8Hr

Webinar by IMechE: https://youtu.be/INNfFoO0fPY?si=UnDJSZ7iQwUXccUu

7) Need more information about literature review?

- See Guideline for Literature Review

- https://writingcenter.tamu.edu/Grads/Writing-Speaking-Guides/Alphabetical-List-of-Guides/Academic-Writing/Literature-Reviews

- https://youtu.be/9la5ytz9MmM

9. Lecture material and topics

• Week 1
1) Introduction to design – Design Process. Design stage. Problem formation. Engineering modeling. CAD. Factor of Safety. Design and safety codes.

2) Important: Systems of Units Note 1

3) Chap. 1

1.6 Systems of Units

** Appendix Appendix Appendix A
** Appendix B Appendix B Appendix B-2
** Appendix C: YoungĄŻs Modulus (E), Shear Modulus (G), PoissonĄŻs ratio, Density, CTE

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4) Static failure theories – Failure of Ductile materials. Failure of brittle materials. Application to design process.

5) Additional resources

- Boeing 777 Wing Test: https://youtu.be/Ai2HmvAXcU0

- Tensile Test: https://youtu.be/D8U4G5kcpcM

- Charpy impact test: https://youtu.be/tpGhqQvftAo

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6) Note 2

• Week 2

1) Important Ąć IC-PBL Course: Support for Prototype Fabrication http://icee.hanyang.ac.kr/surl/E3LB

2) Tempering, Normalizing, and Annealing: https://youtu.be/COasmrnxbqg

3) Chap. 4.16 Thermal stresses

4) Toughness

5) Material properties

Ąć An Introduction to Stress and Strain: https://youtu.be/aQf6Q8t1FQE

Ąć Understanding True Stress and True Strain: https://youtu.be/AkX6JqlWRqc

Ąć Understanding Material Strength, Ductility and Toughness: https://youtu.be/WSRqJdT2COE

6) Hardness: Hardness test https://youtu.be/RJXJpeH78iU

7) Important: Chap. 3

3.2 The static tensile test
   ***Fig. 3.1***
3.3 Implications of the Ą°EngineeringĄą Stress-Strain Curve
   ***Fig. 3.2***
    Sample Problem 3.1
3.6 Estimating Strength Properties from Penetration Hardness Tests
    Sample Problem 3.2
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8) Optional readings

- Chap. 4 Static Body Stresses
- 4.8 Induced Stresses, Mohr Circle Representation
- 4.9 Combined Stresses-Mohr Circle Representation
- Sample Problem 4.3
- 4.10 Stress Equations Related to MohrĄŻs Circle
- 4.11 Three-Dimensional Stresses
- Sample Problem 4.4
Ąć Understanding Plane Stress: https://youtu.be/78K0pbvHzjM

Ąć Understanding Stress Transformation and Mohr's Circle: https://youtu.be/_DH3546mSCM

• Week 3
1) Stress concentration and stress intensity factor

2) What is failure?

3) Static Failure Theories

4) Fatigue failure theories: Note 3

5) Q&A for topic of group project

• Week 4

1) Additional resources for group project
Understanding Viscosity: https://youtu.be/VvDJyhYSJv8?si=E6-zHJuLWtItZqpA

Measuring Viscosity: https://youtu.be/69iUhlqFJFk?si=qWzXL6r0cQjVmFIU

https://www.omega.com/en-us/resources/load-cells

how does it work THE LOAD CELL? Hooke's law - strain gauge: https://youtu.be/ZwuBnBfvoNM?si=fzJZPz4qjaVdoxm0

Example of how to measure load capcaity of bearing: https://ntrs.nasa.gov/api/citations/20020081114/downloads/20020081114.pdf

Fundamentals of fluid film journal bearing operation and modeling: https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/160284/ATPS2016T14.pdf?sequence=1&isAllowed=y
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2) Chap. 4

**4.12 Stress Concentration Factors, Kt**
**4.13 Importance of Stress Concentration**

• Week 5

1) Static failure theories

2) Compressive strength vs tensile strength for ductile and brittle materials

3) Group project: Team discussion

4) Additional resources

https://www.gunt.de/images/datasheet/1399/TM-260.06-Pressure-distribution-in-journal-bearings-gunt-1399-pdf_1_en-GB.pdf

https://www.gunt.de/images/datasheet/1401/TM-280-Pressure-distribution-in-journal-bearings-gunt-1401-pdf_1_en-GB.pdf

https://www.diva-portal.org/smash/get/diva2:830447/FULLTEXT01.pdf

https://www.scce.ac.in/noticeboard/10969_25122017JOURNAL_BEARING_APPARATUS.pdf

http://lib.tkk.fi/Diss/2009/isbn9789522481627/isbn9789522481627.pdf

https://doi.org/10.1016/j.triboint.2020.106345

https://www.mmscience.eu/journal/issues/october-2018/articles/theoretical-and-experimental-analysis-of-the-bearing-journal-motion-due-to-fluid-force-caused-by-the-oil-film/download

• Week 6

1) Important: Chap. 6
Chap. 6 Failure Theories, Safety Factors, and Reliability (**MUST READ***)
6.2 Type of Failure
6.3 Fracture Mechanics-Basic Concepts
6.4 Fracture Mechanics-Applications
Sample Problems 6.1~6.2
6.5 The Theory of Static Failure Theories
6.6 Max. Normal Stress Theory
6.7 Max. Shear Stress Theory
6.8 Max. Distortion Energy Theory
6.9 Mohr Theory and Modified Mohr Theory
6.10 Selection and Use of Failure Theories
***Sample Problems 6.3***
* Nominal Stress - Stress calculated on the basis of the net cross section of a specimen without taking into account the effect of geometric discontinuities such as holes, grooves

2) Group project: Team discussion

• Week 7

1) Selection of Failure Theories: Sample problem in the text book

2) Review of four failure theories in one plot

3) Fully reversed loading vs repeated loading vs fluctuating loading

4) R.R. Moore rotating beam test

5) How to read S-N plots

6) Three S-N plots of fatigue data for typical steel

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7) Definition of fatigue strength

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8) Definition of endurance limit

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9) Generalized S-N curve for steel

Ąć Understanding Fatigue Failure and S-N Curves: https://youtu.be/o-6V_JoRX1g

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10) Absence of endurance limit: Use N=10⁸ or 5*10⁸ cycle

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11) Fully reversed bending test vs axial loading test vs torsional loading test
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12) Important: Chap. 8: Part 1

MUST READ: Chap. 8.1, 8.2
MUST KNOW(**): Figs. 8.3, 8.4, 8.5, 8.9
MUST KNOW: Fig. 8.11

• Week 8

Additional resources for Mid-term exam

Backup figures

Important figures for Mid-term exam

More readings for Mid-term exam

Review for Mid-term Exam

• Week 9

Mid-term Exam

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Final Summary for Mid-term exam
1. Group Project Reflection: You must write at least two complete and comprehensive sentences for your answers.
1) Primary objectives of your group project
2) Your Contribution
3) Lessons Learned
4) Project Progress

2. Units: Note 1

3. Unit of pressure

4. O or X
1) Modulus of Elasticity
2) PoissonĄŻs ratio
3) Modified-Mohr failure theory
4) Fatigue failure
5) fatigue failure
6) R.R. Moore rotating-beam fatigue-testing

5. Stress concentration: Note 3

6. Stress intensity factor: Note 3

7. Fracture toughness: Note 3

8. Static tensile tests: Note 2

9. Note 2
1) YoungĄŻs Modulus
2) Shear Modulus
3) PoissonĄŻs ratio

10. Distortion-Energy Theory, maximum shear-stress theory, and maximum normal-stress theory: Chap. 6 (Textbook)

11. Coulomb-Mohr Theory and the Modified-Mohr Theory: Chap. 6 (Textbook)

12. Units: Coefficient of thermal expansion: Appendix C

13. R.R. Moore Rotating beam test: Textbook

14. Fully reversed stress, Repeated stress, Fluctuating stress: Backup figures

15. S-N curve: low cycle fatigue, high cycle fatigue, fatigue strength, and endurance limit: Important figures for Mid-term exam & Textbook

16. Influence of Surface and Size on Fatigue Strength: Generalized Fatigue Strength Factors: Chap. 8.7 & Chap. 8.8 (Textbook)

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• Week 10

1) Lubrication and Sliding Bearings: Note 4

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2) Rolling-Element Bearings

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3) Webinar by IMechE: https://youtu.be/lKPG-ROuBXQ?si=Fysj_Jfx3fPPxtLa

4) Group meeting

• Week 11

1) Shafts and Associated Parts / Rotating-Shaft Dynamics / Overall Shaft Design

2) Group presentation: Team activity

Ąć Peer Review & discussion

• Week 12

What you should read in Chap. 8: Part 2

Chaps. 8.7 & 8.8

***********Table 8.1***********
******MUST READ: Chap. 8.9*******
MUST KNOW(**): Table 8.2, Figs. 8.16, 8.20
Sample Problems: 8.1 & 8.2

Estimation of fatigue failure criteria, Fluctuating uniaxial stresses, Augmented modified Goodman diagram

Surface failure

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Wear

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What you should read in Chap. 9

**MUST READ: Chaps. 9.8, 9.9, 9.10, 9.11, 9.14, 9.15**

Group presentation: Team activity

Ąć Peer Review & discussion

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Reference for your study: An Engineering Guide for Bearing Selection

Rotational damping and Viscosity

• Week 13

Threaded fasteners and power screws
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Videos

- How It's Made Nuts and bolts

- Multifunctional Wedge-Lock Washers

- Junker Vibration Test

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Rivets, Welding, and Bonding

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Springs

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Videos

- How It's Made Springs

- How It's Made - Leaf Springs

- Wave Springs: https://www.youtube.com/user/SmalleySteelRing

Lab Tour: Turbomachinery and Machine Components (http://turbolab.hanyang.ac.kr/facilities.html)
Q&A for real machinery systems

Group presentation: Team activity

Ąć Peer Review & discussion

• Week 14
Spur gears

Videos

- How It's Made - GEARS

- Gears manufacturing methods

- Gear and Wheels Part 1 & Gear and Wheels Part 2

- How a watch works

More information

- https://en.wikipedia.org/wiki/Gear

- Gears Steer New Engine Designs

Practice: Gear-Tooth Geometry and Nomenclature

Helical gears

Bevel and worm Gears

Videos

- How Differential Gear works

- HOW IT WORKS- Planetary Gears

Group presentation: Team activity

Ąć Peer Review & discussion