异形钢管混凝土轴压短柱力学性能
Mechanical behavior of special-shaped CFT stub column under axial compression
罗靓 1晏宇翔 1吕辉 1张成明1
作者信息
- 1. 南昌航空大学土木建筑学院,江西 南昌 330063;江西省装配式建筑与智能建造重点实验室,江西 南昌 330063
- 折叠
摘要
基于已有混凝土三轴塑性-损伤本构模型和钢材弹塑性本构模型,建立L形、T形、十字形 3 种异形钢管混凝土轴压短柱的三维实体精细有限元模型.在已有试验验证的基础上开展参数分析,对比钢管强度、混凝土强度、腹板高厚比和钢管壁厚对荷载-位移曲线的影响.结果表明:当钢管屈服强度或钢管壁厚增大时,柱的极限承载力明显增大,延性更好;当混凝土强度等级或腹板高厚比增大时,柱的极限承载力增大,但延性变差.确定了 3 种短柱达到极限承载力时的约束区与非约束区面积及其对应的混凝土Mises平均应力,提出考虑约束系数的承载力实用计算公式,此约束系数主要与腹板高厚比有关.将此公式计算得到极限承载力与试验值、有限元值对比,证明了公式的精确性和有效性,可用于 3 种异形钢管混凝土轴压短柱的承载力计算.
Abstract
Based on the existing triaxial plastic damage constitutive model of concrete and the elastic-plastic constitutive model of steel,a three-dimensional solid fine finite element model of L-shaped,T-shaped and cross shaped CFT stub columns was established.On the basis of existing experimental verification,parameter analysis was conducted to compare the effects of steel tube strength,concrete strength,height to thickness ratio of web and wall thickness of steel tube on the load-displacement curves.The results showed that when the yield strength or wall thickness of the steel tube increased,the ultimate bearing capacity of the column significantly increased,and the ductility was better.When the strength grade of concrete or the height to thickness ratio of the web increased,the ultimate bearing capacity of the column increased,but the ductility decreased.The confined areas and unconfined areas and the corresponding mean values of concrete Mises stress were determined when 3 kinds of stub columns reached the ultimate bearing capacity,and the practical calculation formula of ultimate bearing capacity considering the confinement coefficient was proposed.This constraint coefficient was mainly related to the height to thickness ratio of the web.The comparison of the ultimate bearing capacity calculated by this formula with the experimental values and FE values,proved the accuracy and effectiveness of the formula,which could be used for the bearing capacity calculation of 3 types of special-shaped CFT stub columns under axial compression.
关键词
异形钢管混凝土柱/力学性能/有限元分析/极限承载力/约束系数Key words
special-shaped concrete-filled steel tube column/mechanical behavior/finite element analysis/ultimate bearing capacity/confinement coefficient引用本文复制引用
基金项目
国家自然科学基金(52268031)
江西省住建厅科技项目(2023)()
南昌航空大学博士启动基金(EA201911291)
出版年
2024
NETL
NSTL
万方数据