Probabilistic fatigue life prediction of spot-welded joints

A probabilistic fatigue life prediction methodology for spot-welded joints under variable amplitude loading history is presented. The loading history is multi-axial and is obtained from transient response analysis of a vehicle model. A 3-D finite element (FE) model of a simplified joint with four spot welds is developed first to perform static stress analysis. Then, the probabilistic Miner's rule is combined with this stress analysis result to develop a probabilistic fatigue life prediction methodology for the spot weld. This new method is implemented with MSC/FATIGUE and is useful for reliability assessment of spot-welded joints against fatigue.