Is there anyone familiar with the S-N curve when dealing with Fatigue test?
S is the stress,σ? For a specific load, isn't it some stress distribution in the test coupon? How do somes testbooks or some industrial standards use only one stress as an element to describe the material or some metal products' fatigue strength? I executed the fatigue test for some metal-products by the load-controlled servo-hydraulic tig. I have some (load,life)points on the S-N coordination,e.g.(7.2KN,258910cycles),(6.0KN,10000000cycles) .
By the way, is there any formal or concept to define some metal product's fatigue strength?
Thanks a lot if you share me some good information.