Finite element modeling of plastic hinges based on ductility demand‐capacity method using nonlinear material for dynamic analysis

The article discusses modeling plastic hinges in reinforced concrete intermediate supports using finite elements methods. The ductility demand‐capacity method was used to determine the geometrical parameters of cross‐section plasticization zones, their ability to move and rotate, as well as their ductility. Due to the varied geometry and stiffness of the supports and their nonlinear behavior under dynamic load, this method was concluded to be imperfect. Therefore, an improved algorithm was proposed by determining the main parameters of plastic hinges depending on the degree of concrete degradation according to Lubliner's assumptions. The new algorithm has been implemented in the form of mathematical equations. It was subsequently used, at the structure design stage, to perform numerical calculations based on the finite element method.