High School

A steel rod with a 3.5-inch diameter has a machined surface, an ultimate tensile strength of 100 Kpsi, and a yield strength of 68 Kpsi. Given [tex]Sf = f(S_{ULT})[/tex] and it requires 99.9 fatigue cycles, what is the ultimate strength of the steel rod in Kpsi?

Answer :

The ultimate strength of the steel rod is 68.07 Kpsi.

To find the ultimate strength of the steel rod, we'll use the modified Goodman equation: Sf = f(SULT), where Sf is the fatigue strength, f is the factor of safety, and SULT is the ultimate tensile strength.

First, we rearrange the equation to solve for SULT:

Sf = f . SULT

SULT = Sf / f

Given the yield strength (Sy) as 68 Kpsi and a factor of safety (f) of 99.9%, or 0.999:

SULT = 68 / 0.999

SULT} = 68.07 Kpsi

Thus, the ultimate tensile strength of the steel rod is approximately 68.07 Kpsi.

Other Questions