Evaluation of Nonlinear Dynamic Behavior for Steel Moment Frame Structures Considering P-$\Delta$ Effects

P-$\Delta$ 효과를 고려한 철골 구조물의 비선형 동적거동 평가

Inelastic seismic response of steel moment frame structures, which are usually quite gravity load and subject to large displacement under severe earthquake, may be severly influenced by the structure P-Δ effects. The P-Δ effect may have an important impact on the dynamic behavior of the structure in the nonlinear seismic analysis. In multi degree of freedom systems P-Δ effects may significantly affect only a subset of stories or a single story alone. Therefore, a story drift amplification of structure is happened by P-Δeffects and such nonlinear dynamic behaviors are very difficult to evaluate in the structures. In this study, two systems having different design methods of steel moment frame structures are investigated to evaluate the P-Δ effects due to gravity load. The plastic hinge formations, maximum rotational ductility demands, and energy distribution will be compared and evaluated following whether the P-Δ effects are considered or not. And design methods are proposed for the prevention of the instability of structures which due to the P-Δ effects.