STATISTICAL CORRELATION OF FATIGUE LIFE OF 15MNVN STEEL NOTCHED BAR UNDER VARIABLE AMPLITUDE TENSION TENSION BLOCK LOADING

Variable amplitude tension-tension block loading is repeated and appli ed to test 15MnVN steel notched bars. The block loading consists of th ree steps of load increase reaching a peak at the fourth step followed by three steps of load decrease returning to the initial level. The r esults are presented in terms of the probability distribution function . One of the objectives of this work is to show that the probability d istribution correlates well with the fatigue life data of the high-str ength low-alloy steel which exhibits the discontinuous strain hardenin g characteristics and does not have any overload effect. It is shown t hat the fatigue life and critical accumulated damage data follow the l og-normal distribution. (C) 1997 Elsevier Science Ltd.