Engineering Board Exam Reviewer · Engineering Materials · hard
A component is cyclically loaded between a maximum stress of 200 MPa and a minimum stress of −50 MPa. What are the stress amplitude and mean stress?
- a = 125 MPa, m = 75 MPa
- a = 75 MPa, m = 125 MPa
- a = 250 MPa, m = 150 MPa
- a = 100 MPa, m = 0 MPa
Answer
A. a = 125 MPa, m = 75 MPa
Solution
a = ( max - min)/2 = (200 + 50)/2 = 125 MPa; m = ( max + min)/2 = (200 - 50)/2 = 75 MPa. Stress ratio R = min/ max = -0.25.
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