Generic method of local thickening in shell element FEM models for orthotropic bridge decks

This paper presents a method of estimating the hot-spot stress in orthotropicbridge decks (OBD) using a shell Finite Element (FE) model, in which localthickening is applied around the welded. The dimensions of the area of localthickening are a function of the weld throat thickness and the plate thickness.A comparison of this method with 3D solid element FE models is presented forvarious fatigue sensitive details. The comparison is carried out for OBD withtrapezoidal stiffeners, both with continuous stiffeners through crossbeams andwith stiffeners welded in between crossbeams. It is concluded that the accuracyof estimating the hot-spot stress with a shell element model using local thickening is significantly higher as compared to a conventional shell element model without thickening. The method of local thickening is adopted in the new prTS 1993-1-901. This paper functions as the background to this technical specification