10th International Congress on Advances in Civil Engineering, Ankara, Türkiye, 17 - 19 Ekim 2012, ss.1-10
The ductility of steel ever known as non-linear material property causes stress relief with plastic hinge formation and increases the load carrying capacity of structures made of steel can be best incorporated into stress calculations by means of Finite Element Methods (FEMs). The ductility of steel is considered in stress calculations either as a simplification in calculations or directly incorporated into calculations as non-linear material property. The phenomenon, incorporating the complex geometry of steel components and material nonlinearity in stress calculations can be achieved by means of FEMs. The steel orthotropic highway bridges, which are composed of deck-plate, longitudinal stiffeners going through cross-beams, cross-beams with cut-outs, main girders, bridge extensions for pedestrians, are extremely complex in geometry and made of steel, which is ductile in nature. As a result, FEM-stress calculation of orthotropic steel bridge is a perfect example for the investigation of ductility induced stress relief. The traditional constructional details and their dimensions of steel orthotropic highway bridges are given in DIN FB-103. In the scope of this study, based on dimensions recommended in DIN FB-103 and kinematic hardening material property of steel material, a FEM-model of steel highway bridge will be prepared. Results of calculations with and without material non-linearity will be presented and compared with each other in order to demonstrate the decrease in stress because of steel ductility.
Keywords: FEM, kinematic hardening, ductility, orthotropic steel bridges