EVALUATION METHOD OF PLASTIC DEFORMATION CAPACITY OF STEEL BEAM GOVERNED BY DUCTILE FRACTURE AT THE TOE OF THE WELD ACCESS HOLE

摘要

Ductile fracture occurs when the steel beam reaches its ultimate plastic deformation capacity. In order to evaluate the plastic deformation capacity of beam governed by ductile fracture, it is necessary to clarify the plastic strain capacity of the beam-end flange. In this paper, the in-plane beam analysis was conducted to achieve the strain history at the fracture zone. A hysteresis model of the structural steel effective in evaluating material damage was introduced into this analysis. Moreover, loss of beam section due to the weld access holes and the local out-of-plane bending of the tube wall on the RHS column were taken into account to the analytical model. The analytical method was proved by comparing the analytical results to the experimental results from a database. The plastic strain capacity of beam-end flange till ductile fracture was evaluated by studying the analytical flange strain histories.