基于能量法的钢框架结构倒塌工况下抗力分析

Energy analysis of the resistance of steel frame structures based on the progressive collapse

钢框架结构在竖向承重构件突然发生破坏的情况下可能发生连续倒塌,结构主要通过两个抗倒机制防止连续倒塌的发生,分别为小变形状态下的梁机制工作阶段以及大变形状态下的悬链线机制工作阶段。本文对已有研究得到的钢框架抗力-位移曲线进行了适当简化,并运用能量法原理分析了抗倒各个阶段的受力特征以得到曲线各个阶段的表达式,随后应用大型有限元分析软件ANSYS对理论公式的可靠性进行了算例验证。研究结果表明,提出的分析方法较为合理,并为之后的研究工作提供了一种有效的分析方法。

Steel frame structures may occur progressive collapse under the sudden destruction of vertical bearing component. Structures prevent the occurrence of progressive collapse through two resistance mechanisms, including the beam mechanism under small deformation condition and the catenary mechanism under large deformation condition. This paper simplifies the structure resistance curve obtained by former researches, and analysis mechanical characteristics of various stages during progressive collapse for getting formulas of resistance curve at each stage by using energy method. Subsequently, the reliability of the proposed formulas is validated against a case study of an example by using large-scale finite element analysis software ANSYS, and good rationalization is observed. Finally it provides a rational analysis method for relevant researches.