Assessment of notched tubular ferritic oxide-dispersion-strengthened components subjected to multiaxial creep loading at 1100°C (original) (raw)

Notch Effect on Structural Strength of Components at Elevated Temperature Under Creep, Fatigue, and Creep-Fatigue Loading Conditions: Phenomenon and Mechanism

Journal of Pressure Vessel Technology, 2019

Structural discontinuities (e.g., nozzle, hole, and groove) widely occur in many high temperature components of nuclear and fossil power plants. In general, the notched component is used for simplified tests and analyses due to the complexity of the introduction of a practical component. In the previous work, the effects of the notch on failure life of the components have been reported experimentally, including the strengthening and weakening effects; however, the internal mechanisms have not been clearly demonstrated. This work reviews the notch effects on the structural strength of the notched components at elevated temperatures under creep, fatigue, and creep-fatigue loading conditions. Experimental phenomena (i.e., strengthening or weakening effects) for typical notched specimens subjected to the above three loading conditions are summarized, and the related factors for notch effects on creep rupture life or cycle to failure of the components are discussed. The mechanisms for th...

Analysis of stress and strain concentrations in notched members made of alloys D16 and 1460

Technical Sciences

EN The aim of the study was to present findings on the effect of the presence of a notch upon stress and strain concentrations in model members for aeronautical structures, made of selected aluminum alloys, i.e. D16 and 1460. Flat specimens with centrally positioned holes and side cuts, loaded with some bending moment of stress ratio R = 1, were tested. Specialized FEM software (MSC.Patran and MSC.Nastran) was applied to examine stress and strain distributions. The findings are presented in the form of σ[max] and ε[max] values as well as functions of the following factors: α σ, α ε, and αk, computed on the grounds of these values for both different distances from the bottom of the notch and assumed levels of load put on the specimens. Theoretical analysis was supplemented with experimental investigations into the microstructure of fatigue-fracture surfaces in the area of crack initiation and in that of fatigue of a propagating crack. PL Przedstawiono wyniki badań wpływu działania ka...