1. The problem statement, all variables and given/known data (b) A steel alloy has an ultimate tensile strength of 820MN/m2 and a fatigue endurance limit of 390MN/m2. The steel is used in a fatigue application in which the alternating stress is 0.3 times the mean stress. Using the Goodman method with a factor of safety of 1.5 applied determine the maximum allowable alternating stress that will allow safe operation 2. Relevant equations σa = σfat x (σm/σts) Where σa is the alternating stress, σm is the mean stress, σfat is the fatigue endurance limit and σts is the ultimate tensile stress. 3. The attempt at a solution So far I have substituted σa for 0.3 x σm and tried to rearrange this formula, I have however run into problems and am doubting this is the correct method.