Answer
$σ_{r} = 420 MPa$
Work Step by Step
Given:
A fatigue test was conducted in which the mean stress was 70 MPa (10,000 psi), and the stress amplitude was 210 MPa (30,000 psi).
$σ_{min} = -140 MPa$ and $σ_{max} = 280 MPa$
Required:
magnitude of the stress range
Solution:
Using Equation 8.15:
$σ_{r} = σ_{max} - σ_{min} = 280 MPa - (-140 MPa) = 420 MPa$
