Probabilistic Assessment of Low-Cycle Fatigue Behavior of Structural Welds

Abstract

Low-cycle fatigue behavior of structural welds is dependent on material characteristics, geometry at fatigue-critical locations, loading history including residual stresses, and environment. Since these factors may occur randomly and contribute significantly to the uncertainty in design, probabilistic methods are required for their analysis and for the development of appropriate fatigue design criteria. The analysis and prediction of low-cycle fatigue behavior of structural welds is discussed in terms of the foregoing factors. Consideration of statistical uncertainties in the various parameters enables prediction and interpretation of variability in fatigue response, and permits selection of design allowables which correspond to a small probability of unacceptable fatigue performance. These techniques are shown to provide a systematic basis for assessing fatigue reliability of structural welds.