Fatigue damage assessment of various welded joints under uniaxial loading based on energy methods

The present study intends to evaluate fatigue damage of different welded joints under uniaxial loading condition and its response on fatigue lifetime. The main variables influencing the fatigue life of a welded joint are: applied stress amplitude, material properties, geometrical stress concentration factor. Energy approaches were employed to evaluate the fatigue damage of various weld joints under uniaxial loading conditions. Energy-fatigue life (W–N) curves were further discussed and compared for their capabilities in assessing fatigue life of various joints through different parameters including curve slope, life data scatter, and how readily coefficients/constants are determined and employed in the energy methods. The critical plane/energy approach was found to be the most suitable energy-based approach for fatigue damage and life assessment of welded joints by offering sharper W–N curves and less life scatter. This approach also allowed employing readily available material coefficients/properties as compared with notch stress-intensity energy approach.