1. P P 4.7 Stress Concentrations
Chr_part3 P
Abrupt changes in cross-sectional geometry can produce stress concentrations, Kt.
In other words, a uniform stress profile, P/A is no longer valid. P

2. smax > savg Example:
Look at deformation in vicinity of hole. Is it uniform???
Figure: 04-21a
Stress profile is not uniform. smax occurs at area of discontinuity.
smax > savg

3. smax = Kt* savg smax = maximum stress savg = average stress (P/Amin)
Figure: 04-21b,c
smax = maximum stress
savg = average stress (P/Amin)
Kt = stress concentration factor

4. Figure: 04-25

5. Figure: 04-22a
smax = Kt* savg

6. Figure: 04-24

7. Which is worst? Which is best?
Figure: 04-23c
Which is worst? Which is best?

8. Plate is 1,000 mm long, 400 mm tall and 10 mm thick with a load of 4 kN. Find max stress.
What not to do:

9. Possible stress singularity
Region of interest

10. Stress concentrations around holes and sharp corners!
Figure: UN
Stress concentrations around holes and sharp corners!

15. Figure: P4.111

16. Design problems w/ Kt can involve iterations
Figure: P4.89
How would you design this?