方形不锈钢管超高性能混凝土(UHPC)短柱轴压性能研究  

AXIAL COMPRESSION PERFORMANCE OF UHPC FILLED SQUARE STAINLESS STEEL TUBE SHORT COLUMNS

作　　者：唐红元[1] 胡晓维 刘烨 TANG Hong-yuan;HU Xiao-wei;LIU Ye(Institute of Structural Engineering,Xihua University,Chengdu 610039,China;School of Architecture and Environment,Sichuan University,Chengdu 610065,China)

机构地区：[1]西华大学结构工程研究所,成都610039 [2]四川大学建筑与环境学院深地科学与工程教育部重点实验室,成都610065

出　　处：《工程力学》2024年第12期116-127,共12页Engineering Mechanics

基　　金：国家自然科学基金项目(52208496)。

摘　　要：方形双相不锈钢管超高性能混凝土(ultra-high performance concrete,UHPC)短柱是一种创新高效的组合结构形式。为了研究其轴压承载力性能,该文设计了9根双相不锈钢管UHPC短柱、3根双相不锈钢管普通混凝土短柱和3根双相不锈钢管试件。试验的主要参数为双相不锈钢管宽厚比和核心混凝土强度。试验结果表明:套箍系数是影响方形双相不锈钢管UHPC短柱试件破坏形态和极限轴压承载力的主要因素。随着不锈钢壁厚从4 mm增大为8 mm,方形双相不锈钢管UHPC短柱试件的破坏形态由剪切型变为“镦粗”型,试件极限承载力的平均提升率为55.43%,试件残余强度剩余率的平均提升率为17.45%。同时,讨论了试件的强度提升指数、混凝土贡献率及延性等基本力学性能,分析了倒角对短柱试件刚度的影响,提出了核心混凝土有效约束区的划分与试件宽厚比的关系。基于试验结果和Mander约束混凝土模型,采用叠加原理建立了精确度较好的方形双相不锈钢管UHPC短柱极限承载力预测公式。Ultra-high performance concrete(UHPC)filled square duplex stainless steel tube short column is an innovative and efficient composite structural member.In order to study the axial compressive behavior,the designed is nine UHPC-filled,three conventional concrete-filled duplex stainless steel tube short columns and,three hollow duplex stainless steel tube specimens.The main parameters include the width-to thickness ratio of duplex stainless-steel tube and the strength of core concrete.The results show that the confinement coefficient is the main factor influencing the failure mode and ultimate capacity of UHPC-filled stainless steel tube short column.With the increase of thickness of the tube from 4mm to 8mm,the failure mode of UHPC-filled duplex stainless steel tube short column specimens changed from shear type to"waist drum"type.And the average increase rate of ultimate bearing capacity of UHPC-filled square duplex stainless steel tube short column specimens is 55.43%,and the average increase rate of ductility is 17.45%.The basic mechanical properties of specimens were discussed such as strength improvement index,concrete contribution rate and,ductility index.The effect of chamfering on the stiffness of short column was analyzed.Based on the test results and confined concrete model of Mander,one prediction formula of ultimate bearing capacity of UHPC-filled square duplex stainless steel tube short column with good accuracy was established by a superposition principle.

关 键 词：钢管混凝土 双相型不锈钢 UHPC 轴压试验 破坏模式 计算模型 

分 类 号：TU398.9[建筑科学—结构工程]