Study on fatigue life estimation method of welded structure of lifting machinery

The fatigue strength of lifting machinery structure has always been an important issue in ensuring safety. In order to effectively and accurately evaluate the fatigue life of lifting machinery structure, this paper based on Miner linear cumulative damage theory and S-N curve in British BS 7608 standard, the fatigue life calculation of metal welded structure is carried out. Taking the large-scale bridge crane of hydropower station as an example, the nominal stress of the corresponding key parts is obtained by applying the actual load in the finite element model, and the stress time history is calculated, and then the safe service life of the structure is estimated, which provides an effective and feasible method for evaluating the fatigue residual life of the crane. The example analysis shows that the calculation method is convenient and reliable, which provides a scientific basis for accurately estimating the fatigue life of welded structure of lifting machinery.