Shaft Design for INFINITE LIFE and Fatigue Failure in Just Over 10 Minutes!

DE-Goodman, DE-Morrow, DE-Gerber, DE-ASME, etc.
Mean and Alternating Stresses,
Fatigue Failure,
Infinite Life,
Shaft Design Equations
0:00 Common Shaft Stresses
0:45 Torsion and Bending
2:15 Mean and Alternating Stresses
2:42 Principal Stresses
3:24 Von Mises Stress
3:52 Fatigue Failure Equations
4:57 Shaft Design Example
6:30 Stress Calculations
7:00 Capital A and B Factors
Previous Video:
Fatigue Failure Criteria in Just Over 10 Minutes
• Fatigue FAILURE CRITER...
Example 1: • Shaft Design - Moments...
Example 2: • Shaft Design - Angled ...
Example 3: • Shaft Design - Given A...
Next Video:
Power Screws - Torque to Force Relationships in Just Over 10 Minutes
• Power Screws - Torque ...
Negligible Shear Stresses: Example Exercise in:
Castigliano's Theorem in Under 10 Minutes
• Castigliano's Theorem ...
_____________________________________________
Other "Mechanical Engineering Design 1" Links:
1. Axial Loading Review • Axial Loading Review f...
2. Torsion Review • Torsion Review for Mec...
3. Pure Bending and Deflection Review • Bending Review for Mec...
4. Pure Bending and Deflection Combined Example • Deflection of Beams Re...
5. Shear and First Moment About Neutral Axis Review • Transverse Shear Revie...
6. Mohr's Circle Review • COMPLETE Mohr's Circle...
7. Brittle Failure Theories - Fracture Criteria • Brittle Failure Theori...
8. Ductile Failure Theories - Yield Criteria • Ductile Failure Theori...
9. Design Factor and Uncertainty vs. Factor of Safety • DESIGN FACTOR and Unce...
10. Tolerance Stack Ups and Tolerance Loops • Uncertainty for Design...
11. Castigliano's Theorem • Castigliano's Theorem ...
12. Fracture Toughness • FRACTURE TOUGHNESS and...
13. Crack Propagation • CRACK PROPAGATION and ...
14. Fatigue SN Diagrams • Fatigue (Strength-Numb...
15. Marin Factors and Corrected Endurance Limit • Marin Factors for ENDU...
16. Fatigue Stress Concentration and Notch Sensitivity Factors • Fatigue STRESS CONCENT...
17. Fatigue Failure Criteria • Fatigue FAILURE CRITER...
18. Shaft Design and Iterative Process • Shaft Design for INFIN...
19. Power Screws - Torque to Force Relationship • Power Screws - Torque ...
20. Screw Thread Stress • Stresses at Screw Thre...
21. Fastener and Member Stiffness • Bolt (Fasteners) and M...
22. Bolt Tension • BOLT TENSION and Tensi...
23. Proof Strength and Factors of Safety • PROOF STRENGTH - Facto...
24. Spring Stress and Spring Constant • Mechanical Springs - S...
25. Shearing Yield Strength and Presetting • Springs - PRESETTING a...
26. Springs Fatigue - Zimmerli Data • Springs Fatigue and ZI...
27. Spring Design Restrictions • Mechanical SPRING DESI...
28. Extension Springs • EXTENSION SPRING Desig...
29. Gear Relations and Nomenclature • GEARS BASICS - Nomencl...
30. Gear Trains and Planetary Gears - Mechanical Advantage • Gear Trains and PLANET...
31. Spur Gear Forces and Force Components • Gear Forces and Power ...
32. Helical and Bevel Gear Forces • Gear Forces of HELICAL...
33. Worm Gear Forces • WORM GEARS - Forces an...
34. Bending Stress at the Teeth - Lewis Form Factor • LEWIS BENDING STRESS a...
35. Pitting - Surface Compressive Stress • Gear PITTING - Surface...
36. Bearing Radial Loads • BEARINGS BASICS and Be...
37. Bearing Reliability • Bearings RELIABILITY a...
38. Bearing Axial Loads and Equivalent Combined Loads • Bearings - COMBINED Ra...

[@rybread5718]

Dude, this is insanely helpful for my final project! Thanks man!

[@bentuinstra4441]

Just discovered this channel. Absolutely insane!!

[@architectman100]

Thank you so much! A great refresher!!!!

[@andrewmaksimovich2432]

Didn't know there were such high quality videos on ME topics like this, soooo helpful as a student

[@riccardotonin1732]

This video said what my mech Eng teacher did not teached in 6 months of course. Thanks a lot :)

[@vilivont4436]

Great stuff

[@sodapop8613]

Amazing content!

[@daehyunpark3664]

Thanks for your excellent way of delivering your lecture with nice illustration, hand writing and concise concept! I am a gear design engineer, and I would like to watch many lectures here to refresh my memory from university years. By the way, can you share with me how you create the electronic lectures? (device, software and on). I used my own note with ipad pro, but my hand writings in that device is not as expected, but when I look at yours, the hand writings are so natural!. It would be appreciate how you create the notes!

[@SuperExibo]

Thank you very much!

[@alexandria1772]

Damn incredible good job

[@sam12345768]

The best-ways to follow this learning from this video is not focusing on the formulas and calculations but listen the lectures most important facts,core information and concepts are stated even if it is fast explanations.

[@LessBoringLectures]

Correction: the fillet radius should be 5/16", not 3/16" for the example at 5:05. Thanks to John Finan for pointing this out.

[@user-zx3ls1dc8p]

superb

[@EhsanMoallef-ds6wh]

Very good

[@majedrichardsenbol6116]

Nice summary and explanation, but I have to ask how can I determine the stress concentration factors when designing for a new shaft, when I don't have any dimensions yet, like the fillet radius and the diameter of the shaft. How can I know kb ( size factor ), (r/d, D/d) to find Kt, Kts, Kf, Kfs. Thank you

[@saiprakash8096]

Thanks Sir

[@abdelkaderahmed496]

God bless you, you saved me a lo tof time

[@LoserKing696]

Hello! Any idea what would happen in the case where we have an alternating bending moment acting on a rotating shaft? What usually happens is that we have a static bending moment acting on a rotating shaft, and the rotation causes the bending load to fully alternate. But I have never found an example in which the bending moment itself is alternating (ex. Mb = 10 +/- 5 Nm) WHILE the shaft is rotating. What would we write in the fatigue failure criterion for the bending stress in such an example?

[@rafaymalik9705]

Can we also use the same formula to determine "n" when Sut and Sy are given in MPa? (We would convert them to Pa and then substitute in the formula for n, correct?)

[@EhsanMoallef-ds6wh]

Big like

[@kattyhoho3371]

How can I apply this to calculate shaft for shredder?

[@MrDemonhell1000]

At 7:40 , the alternating shear should equal to transverse shear stress due to forces acting on gear. This is because the shaft is rotating hence causes the transverse shear stress to alternate.

[@LessBoringLectures]

Transverse shear is usually not considered for shaft design (unless the shaft is short and thick, which is usually not the case). The transverse shear values don't contribute much to the shearing stresses, and are therefore usually negligible.

[@lexluthor8783]

Can this information be used to design vertically suspended shafts?

[@Sssmartking]

I think there is a tiny mistake, r is not 3/16, it's 5/16 you can see this in minute 9:20 5/16=0.3125 thanks a lot for this video its very rich and useful

[@andreasdavid1476]

if i have a solid shaftwithout notches the value for kf can be negleted right?

[@hosamalhunaity7362]

what is the app you demonstrating on?

[@abubackarsiddiq4278]

only for high speed brain this can be understand consider slowing down

[@yuchenyang9386]

Great stuff man, really appreciated for those equations and methods. By the way is there any place where I can download or purchase your notes? If there is, then you do a huge favor to me.

[@LessBoringLectures]

Thanks! I'll find a way to share these soon, and let you know.

[@bbb-th1vu]

you really dedicate yourself into your videos, i can see that and i am thankfull for that. But you are reading? or you sound like you are reading. Tonning in your voice made me sleepy, your voice is nice no problem about that. Just tonning. i believe if you adjust this, it would be beter. thank you

[@anilaxsus6376]

why is Kc equal to 1 when von misses stress is used, is it just a fact or is there a reason behind it

[@LessBoringLectures]

The reason for the Marin Factors is purely experimental, but they match the values obtained using the von Mises stress for torsion only. Therefore, when using von Mises stresses, Kc should always be 1, as the von Mises stress is already accounting for it.

[@theerdem4698]

at Ma you multiply 3.5 in with 600 instead of 6000

[@LessBoringLectures]

You’re right, thanks for pointing it out. However it’s only the 600 missing a zero in the sum of moments about A. Notice that the resultant 19000 and all the other values are still correct.

[@rustamali8309]

How you have take "' Se"' endurance stress ?

[@LessBoringLectures]

Can you rephrase the question?

[@rustamali8309]

I mean, How did you get the value of Se=24ksi Can you calculate at this comment platform PLEASE

[@LessBoringLectures]

@@rustamali8309 Se is given as part of the problem. No calculations were carried out to find it.

[@juanandressiciliano6467]

@@rustamali8309The problem gives you either the material or the properties. The properties are given in the back of some books, e.g. Shigleys Mechanical Engineering Design.

[@somshridhar]

Very fast Sir. Want to understand but not able to cpture the speed even though it looks useful

[@johnfinan2634]

3/16 is not 0.3125

[@LessBoringLectures]

thanks for catching that!

[@Deighvihd]

took my prof 7 weeks...

[@heldersimoes1124]

great lecture, very objective indeed. except, your monotonous way of speaking makes it very hard for me to focus.

[@tameratlegesse743]

Tþ

[@llawliet9443]

Damn you lost me 1 minute in