Abstract
Generally the critical distance stress theory was applied for the fatigue limit estimation of general structures using fatigue limit of smooth specimen (σ_<w0>), and threshold stress intensity factor range (ΔK_<th>). In this paper we extended this method for the estimation of low cycle fatigue life too. In this method we define the critical distance (r_c') on static strength conditions, which is calculated using ultimate tensile strength (σ_B) and fracture toughness (K_<IC>), in addition to the critical distance on fatigue limit condition (rc). Then the critical distances of any low cycle fatigue conditions can be calculated by interpolation of critical distance on fatigue limit (r_c) with critical distance on static strength (r_c'). By unifying these low cycle fatigue life estimation method with high cycle fatigue limit estimation method we can estimate the full range fatigue life easily. And to confirm the availability of this estimation method we perform the fatigue test for any stress concentration specimens and fretting fatigue specimens.--
