A dynamic elasto-plastic analysis on the web plates at the center part of beam in a steel portal frame

The authors made a dynamic analysis on a steel portal frame under the ground motion of an earthquake. In this paper, the results of the analysis are presented. In the Kobe earthquake (1995), many steel bridges were damaged and collapsed completely or slightly. With in these damages, shear buckling of the beam of a steel portal frame used as a pier of a motorway viaduct is focused in this paper. On this type of buckling, some researchers have considered that this deformation of the web plates absorbs the energy due to the earthquake, and therefore catastrophic collapse is avoidable in this structure. The authors tried through the experiment and the numerical analysis to confirm this idea. Within the current analysis, it is noted that is the shear collapse and the ductility in a steel portal frame. In this paper, the results of the analysis are shown.