MIL-HDBK-5J FATIGUE TERMINOLOGY 1

[jonhoward]

I AM EXAMINING THE S/N FATIGUE CURVES AND WAS WONDERING IF SOMEONE MAY BE ABLE TO EXPLAIN THE DEFINITION OF THE RUN-OUT SHOW ON THE CURVES/DATA POINTS. ALSO WHAT IS MENT BY THE STRESS RATIOS. THANK YOU VERY MUCH FOR YOUR TIME AND ASSISTANCE.

 

[jonhoward]

I have figured it out as runout being a test that is interrupted before failure and that the stress ratio is the ratio of the minimum stress to maximum stress in one cycle of loading in a fatigue test. Tensile stresses are considered positive and compressive stresses are negative....