Local stress-strain field intensity approach to fatigue life prediction under random cyclic loading

According to the characteristic of the local behavior of fatigue damage, on the basis of stress field intensity approach, a theory of local stress-str ain field intensity for fatigue damage at the notch is developed in this pa per, which can take account of the effects of the local stress-strain gradi ent on fatigue damage at the notch. In order to calculate the local stress- strain field intensity parameters, an incremental elastic-plastic finite el ement analysis under random cyclic loading is used to determine the local s tress-strain response. A local stress-strain field intensity approach to fa tigue life prediction is proposed by means of elastic-plastic finite elemen t method for notched specimens. This approach is used to predict fatigue cr ack initiation life, and good correlation was observed with U-shape notched specimens for normalized 45 steel. (C) 2001 Elsevier Science Ltd. All righ ts reserved.