연쇄붕괴방지를 위한 H형강의 좌굴후 에너지흡수 능력평가에 관한 연구

Abstract

The buckling load in the elastic range of steel column member has been the subject of several studies. Majority of such research studies have been conducted within the range of initial plastic buckling load and small strain. Moreover, structural design mainly covers the initial bifurcation buckling and small strain. The load?deformation curve of an inelastic column was primarily handled in the aspect of an elasto-plastic hardening effect rather than restoring force decrease. As steel columns under unexpected accidental loading exhibit a large buckling plastic deformation capacity, there is much discussion on the issue associated with the evaluation of deformation capacity and restoring force of column members in the large post-buckling deformation range. According to the AIJ/LSD guidance, although stable restoring force in post-buckling was suggested, it is the calculation of the horizontal load-carrying capacity of the brace, which refers to the remaining force in the deformation range in which axial deformation ratio is 1%. Thus, the proposal cannot be applied as post-buckling force in the large deformation range which ranges dozens of percentage points. Although research into the plastic post-buckling range includes Paris and Koto, research into deformation capacity and strength of as much as 20?30% of the axial deformation ratio in the large deformation range is extremely limited. Accordingly, there is a need for research studies on the entire range of plastic deformation. Furthermore, although a simple expression of Ba?ant is available for an analysis method using the hinge model, further verification is required through more accurate analyses and tests. In the study, using the plastic deformation energy of members to prevent the progressive collapse of structures, basic research was carried out to examine if progressive collapse can be prevented by absorbing the energy of the collapse loading of structures. In order to examine the possibility of residual post?buckling restoration force supporting vertical load after the progressive collapse comes to a complete stop, the post-buckling strength of the H-shaped column member and the plastic deformation capacity were reviewed through tests. Furthermore, comparison was made between the value obtained from the loading test and the results following a non-linear FEM analysis.