湖南大学学报（自然科学版）2025，Vol.52Issue(11)：1-14,14.DOI:10.16339/j.cnki.hdxbzkb.2025101
高强耐火钢方钢管混凝土柱极限承载力研究
Study on Ultimate Bearing Capacity of Concrete-filled High-strength Fire-resistant Square Steel Tubular Columns
摘要
Abstract
To study the overall bearing capacity of concrete-filled fire-resistant square steel tubular(CFFRSST)columns under axial compression,six CFFRSST columns were designed and tested.The study examined the ultimate bearing capacity and strain development at key locations of the specimens with different welded residual stresses,slenderness ratios,with-to-thickness ratios,and steel strength grades.Besides,the finite element models(FEM)of CFFRSST columns were established,considering the welded residual stress.Based on the validated FEM,further analyses were conducted to evaluate the influence of the welded residual stress,slenderness ratio and width-to-thickness ratio on the axial compression behavior.The results show that the overall stability coefficients of CFFRSST are higher than that of conventional-strength steel concrete-filled square steel tubular(CSSCFSST)columns due to the lower welded residual stress of fire-resistant steel than conventional-strength steel.Furthermore,the differences in overall stability coefficients between the CFFRSST column and the CSSCFSST column increases initially and then decreases with the increase of slenderness ratios.Short columns are more prone to strength failure,and their ultimate bearing capacity are significantly influenced by the interaction between the steel tube and the concrete.As the width-to-thickness ratio decreases,the concrete compressive strength improves due to the constraint effect,leading to a higher stability coefficient.In contrast,the failure of medium and long columns is primarily governed by second-order effects,where the constraint effect is less pronounced.The stability coefficient of columns is primarily affected by welded residual compressive stress,which increases as the width-to-thickness ratio increases.The ultimate bearing capacity obtained from the parametric analysis were compared with predictions from current design codes.The results show that the predictions from Chinese and American codes are lower than the parametric analysis by about 32%and 9%,respectively,while the European code underestimates it by about 7%,providing the most accurate predictions among the three.关键词
方钢管混凝土柱/耐火钢/抗火性能/焊接残余应力/承载力Key words
concrete-filled square steel tubular column/fire-resistant steel/fire resistance/welded residual stress/bearing capacity分类
建筑与水利引用本文复制引用
王彦博,陈美玲,叶泽华,李国强..高强耐火钢方钢管混凝土柱极限承载力研究[J].湖南大学学报（自然科学版）,2025,52(11):1-14,14.基金项目
上海市科技计划项目(23DZ1202303),Science and Technology Program of Shanghai(23DZ1202303) （23DZ1202303）
