Plan for Wednesday, November 24, 2015
9:00
Review
- Fluctuating stresses
- Must check for yielding and fatigue failure
- Equivalent fully reversed stress is needed to determine finite life cycles for fluctuating stress.
Goals
- Discuss pure torsion loading
- Compound loading
9:05
Self driving car videos and pictures
9:10
Quiz
9:20
Torsion (6-13)
- \(S_{su} = 0.67 S_{ut}\)
- \(S_{sy} = 0.577 S_{yt}\) (distortion engery theory)
- \(k_c = 0.59\)
Combined loadings
- generate two stress elements: mean and amplitude
- compute von mises stress
- don't use \(k_c\) for torsion, cause accounted for
9:25
Compound loading example
9:40
Lots going on next week (last week of classes):
Homework #8 due on Monday (two fluctuating stress and one fluctuating compound loading)
Dynamic Loading Memo
- Where are the largest stresses seen from dynamic loads?
- How did you estimate the sigma max andd sigma min for the critical areas?
- What static and fatigue material properties did you obtain for your material choices?
- What type of fatigue stresses are seen?
- Factor of safety?
Lightning talks on Friday
- Can use visuals: doc camera, board, projector
- 5 minutes to pitch your design (you will be cut off)
- Pick one team member that is the best speaker and have them practice in front of you beforehand.
- One method: ten slides at 30 seconds each
- Each member develops ~2 slides, writes 30 second script, one person practices it
- Look up pechakucha: concise presentations
- It takes more time than you expect to make it concise!
- The best talk will get a prize!
- Andy Wyly will come to help judge.
Feedback!!