Finite element validation and model updating of beam in agricultural mower for fatigue assessment

Agricultural disc mowers are used to cut crops in the field and are exposed to cyclic loading during their lifetime. A cutterbar is an essential part of a disc mower and consists of multiple parts welded together. This paper aims to develop a finite element model of a cutterbar, which can be used for fatigue assessments of the welded joints. A quasi-static experiment has been performed to validate the finite element model based on strain measurements. The finite element model has been updated using a parameter based method as several discrepancies were observed. The updated model reduces the mean absolute error of strain values from 7.5 % to 4.7 %. The hot spot approach has then been used to analyze three different weld locations on the cutterbar. The fatigue criterion by the International Institute of Welding has been used to determine the relative fatigue lives of the weld locations. The back weld is shown to be most exposed, which fits well with results from prior experiments.