华南理工大学学报（自然科学版）2025，Vol.53Issue(12)：94-106,13.DOI:10.12141/j.issn.1000-565X.240596
多层框架-稀疏人字撑结构的抗侧力性能
Lateral Resistance of Multi-Storey Steel Frame with Sparse Chevron Bracings
摘要
Abstract
This study conducts an in-depth investigation into the lateral resistance of multi-storey steel frames with sparse chevron bracing.By combining finite element analysis and theoretical derivation,the mechanical behaviour of structures with under-strengthened beams and its influence on lateral resistance are systematically examined.Through elastoplastic pushover analysis,the accuracy of the series-parallel theoretical model for dual lateral force-resisting systems is validated,and the variation of bracing internal forces with inter-story drift angle is revealed.Fi-nite element results indicate that the stiffness and strength of beams significantly influence the development of ten-sile brace forces after buckling of the compressive brace.As a secondary lateral force-resisting system,the frame ef-fectively compensates for the degradation in load-bearing capacity after brace buckling.In addition,the composite effect of the slab effective width and steel beam notably enhances the flexural stiffness of beam,thereby facilitating the development of tensile brace forces,and reducing the degradation of load-bearing capacity after compressive brace buckling.For rigid frame-chevron bracing structures with inadequately strengthened beams,under the com-bined action of lateral displacement and unbalanced forces,plastic hinges in the beam initially form at the beam end on the compressive brace side,followed by the mid-span of the beam.Based on this failure mode,formulas for calculating tensile brace forces and beam unbalanced forces are derived,demonstrating high accuracy.The study indicates that even when beams do not meet the sufficient strengthening requirements specified in Clause 8.2.6-2 of the Code for Seismic Design of Buildings,the overall load-bearing capacity does not deteriorate with increasing lateral displacement,provided that the frame contributes a relatively high proportion of lateral resistance.This en-sures structural safety under seismic actions with an intensity of 7 degrees(0.1g).The proposed calculation method for beam unbalanced forces provides a new approach to optimizing chevron-braced frame design,avoiding the prob-lem of excessively large beam depths in traditional design,and offering important theoretical support and practical guidance for engineering applications.关键词
人字撑/双重抗侧力结构/横梁刚度/楼板有效宽度/支撑内力Key words
chevron bracing/dual lateral resistance structure/stiffness of the beam/effective width of the slab/bracing internal forces分类
建筑与水利引用本文复制引用
何亮,许照宇,沈文杰,童根树,刘志鑫,张磊..多层框架-稀疏人字撑结构的抗侧力性能[J].华南理工大学学报（自然科学版）,2025,53(12):94-106,13.基金项目
浙江省自然科学基金重点项目(LZ22E080004)Supported by the Key Program of the Natural Science Foundation of Zhejiang Province(LZ22E080004) （LZ22E080004）
