Application of various low cycle fatigue evaluation rules to notched compact tension specimen test data

Existing low cycle fatigue evaluation methods are applied to notched C(T) specimens test data of low alloy and stainless steels to quantify conservatism embedded in evaluation methods. Three methods are considered: American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code Sec. III simplified elastic-plastic analysis method, elastic-plastic fatigue analysis method given in the Japan Society of Mechanical Engineers (JSME) Code Case (CC) and elastic-plastic fatigue analysis method using the cyclic void growth-shrinkage model (CVGSM). The conservatism is quantified via cumulative usage factor (CUF). The simplified elastic-plastic analysis method given in ASME B&PV Code Sec. III is the most conservative. Using the best-estimate fatigue curve, calculated CUF values are around 5 to 7 using the simplified elastic-plastic analysis method. Elastic-plastic fatigue evaluation methods improve the accuracy. Calculated CUF values decrease to 2 to 3 when the JSME Code Case and the CVGSM are used. Effects of the cyclic hardening model for elastic-plastic finite element (FE) analysis and material input data (fatigue curve or fracture strain) on calculated CUF values are also investigated.