Posted by Danny on .
The ultimate strength of a steel rod is 600.000MPa. if the factor of safety 3.000 is required, what is the maximum permissible load for the rod if it has a diameter of 6.000cm?
ANS = kN (Round to 3 decimal place)
Ultimate strength = 600.000MPa = 600000000Pa = 600 * 10^6
Factor of Safety = 3.000
Rod diameter = 6.000cm = .06m
Allowable Strength
= Ultimate strength/ Factor of Safety
= 600* 10^6/ 3 = 200 * 10^6 (or)
= 600000000/3 = 200000000
Allowable Strength
= Load/ Area
Load
= Allowable Strength * Area
= Allowable Strength * (pi*d^2/4)
=600*10^6*pi*.06^2/4
=600000000*3.1416*.0036/4
=6785856/4
=1696464N
=1696.464kN
Please check. Thank you.

Physics (Stress & Stain) 
bobpursley,
no. you need to divide the max load by 3, somehow you dropped that.

Physics (Stress & Stain) 
Danny,
Load
= Allowable Strength * Area
= Allowable Strength * (pi*d^2/4)
=200*10^6*pi*.06^2/4
=200000000*3.1416*.0036/4
=2261952/4
=565488N
=565.488kN
Please check. Thank you.