Fatigue life prediction of the metalwork of a travelling gantry crane

Intrinsic fatigue curves are applied to a fatigue life prediction problem of the metalwork of a travelling gantry crane. A crane, used in the forest industry, was studied in working conditions at a log yard, and strain measurements were made. For the calculations of the number of loading cycles, the rainflow cycle counting technique is used. The operations of a sample of such cranes were observed for a year for the average number of operation cycles to be obtained. The fatigue failure analysis has shown that failures of some elements are systematic in nature and cannot be explained by random causes.