钢板剪力墙结构基于性能的塑性设计方法研究

依据现行设计规范设计的钢板剪力墙结构,在罕遇地震作用下的非弹性性能是难以预测和控制的。为满足对高效可靠设计的需求,该文提出了钢板剪力墙结构基于性能的塑性设计方法,并通过修正楼层剪力考虑结构的P-Δ效应。选用预定的目标位移和破坏模式作为结构的两个关键性能指标。根据能量守恒原理,计算结构在给定地震作用下的设计基底剪力;采用能够反映结构在罕遇地震下楼层剪力分布状态且考虑高阶振型影响的侧向力分布模式,确定楼层剪力;采用塑性设计方法设计内嵌钢板以便达到预期的破坏模式和性能。为验证方法的有效性,采用此方法对一栋10层钢板剪力墙结构进行了设计,并采用静力非线性分析法和动力弹塑性方法对结构进行分析,为钢板剪力墙结构基于性能的塑性抗震设计提供一定依据。

PERFORMANCE-BASED PLASTIC DESIGN METHOD FOR THE SLENDER UNSTIFFENED STEEL PLATE SHEAR WALLS

The existing codes and design guidelines for thin unstiffened steel plate shear walls (SPSWs) fail to evaluate the inelastic behavior of SPSWs under the maximum considered earthquake (MCE) level ground motion. Considering the ever-increasing demands of efficient and reliable design procedures, a performance-based plastic design method for slender unstiffened SPSW systems is proposed in this work, which sets a target drift and a preferred yield mechanism as its performance targets. Also investigated is the P-Δ effect on the seismic demand of SPSW. The design base shear for a given hazard level is derived based on the inelastic state of SPSWs, with the drift control built-in, by equating the work needed to push the structure monotonically up to the target drift to that requited by an equivalent elastoplastic single-degree-of-freedom (EP-SDOF) system to achieve the same state. The effectiveness of the proposed method is illustrated through the sample case study of a ten-storey SPSW building, and validated by pushover as well as dynamic elastic-plastic analyses. The addressed method herein can form a basis for the performance-based plastic design of SPSW systems.