Question

Pmax=80 kips and Pmin=20 kips. Assume the load is equally distributed to all the bolts. It has been determined to use ½ in-13 UNC grade 8 bolts. Determine the fatigue factor of safety using the Goodman criteria.

Answer 1

Step-by-step explanation:

Minimum Proof strength (sp) = 120 kpi

minimum tensile strength (sat) = 150 kpi

Now, calculate the load per each using the equation

`p=(80)/(N) \mathrm{ki}`

calculate the preload for non permanent connection

`F=0.75 \mathrm{sp} \mathrm{At}`

`F=0.75 * 120 * 0.1419`

`F=2.77 kip`

Calculate the stiffness constant for the assenbly

`c=(k p)/(k_(p)+k_(m))`

Substitute

`c=(4 * 10^(6))/(\left(4 * 10^(6)\right)+\left(12 * 10^(6)\right))`

c=0.25