中空夹层圆钢管超高强混凝土短柱火灾后承载性能试验研究  

Experimental study on post-fire bearing performance of ultra-high strength concrete filled double-skin circular steel tubular column

作　　者：吕晓 赵瑞丽 舒赣平[3] 张鑫[1,2] 杜二峰[3] 王文明[1,2] LÜXiao;ZHAO Ruili;SHU Ganping;ZHANG Xin;DU Erfeng;WANG Wenming(School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering(Shandong Jianzhu University),Ministry of Education,Jinan 250101,China;School of Civil Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]山东建筑大学土木工程学院,山东济南250101 [2]建筑结构加固改造与地下空间工程教育部重点实验室,山东济南250101 [3]东南大学土木工程学院,江苏南京211189

出　　处：《西安建筑科技大学学报（自然科学版）》2022年第4期543-550,共8页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：国家自然科学基金重点项目(52038006);山东省自然科学基金面上项目(ZR2021ME190);山东省高校土木结构防灾减灾协同创新中心项目(XTP201919)。

摘　　要：为研究中空夹层钢管超高强混凝土受压构件火灾后的力学性能,开展了4个火灾后中空夹层圆钢管超高强混凝土短柱轴压试验,夹层超高强混凝土的抗压强度超过160 MPa,通过试验结果可以看出,试件的荷载-位移曲线可以分为四个阶段:弹性阶段、弹塑性阶段、塑性阶段和下降阶段.结果表明:即使试件已经历前期耐火极限试验,该组合构件仍有较好的剩余承载能力和延性性能.剥去试件部分外钢管,对夹层超高强混凝土的碎裂、外钢管的凸曲及内钢管的凹曲破坏机理进行了阐释.建立中空夹层圆钢管超高强混凝土柱有限元计算模型,考虑钢管壁与夹层混凝土之间的接触效应,并根据材性试验对已有的钢材及混凝土火灾后的材料本构关系模型进行修正,将修正后的材料本构关系模型应用到试件数值模拟中,最终计算得到试件有限元模型的破坏模式与试验后的破坏模式近似,荷载-位移曲线计算结果与试验结果吻合较好,试件经历的最高温度对剩余承载力影响显著.In order to further study the mechanical properties of ultra-high strength concrete-filled double-skin circular steel tubular column after fire,axial compression test of four short circular steel tubular column specimens was carried out with sandwich concrete strength of more than 160 MPa.It can be seen from the test results that the load-displacement curve of the component can be divided into four stages:elastic stage,elastic-plastic stage,plastic strengthening stage and descending stage.This shows that the composite component has better residual bearing capacity and ductility performance even if it has undergone previous fire resistance test.By stripping the outer steel tube of the specimen,the fracture mechanism of the interlayer ultra-high strength concrete,the convex bend of the outer steel tube and the concave bend of the inner steel tube are explained.The finite element model of ultra-high strength concrete-filled double-skin circular steel tubular column is established,and considering the friction effect between steel tube wall and sandwich concrete,the material constitutive relation model of steel tube and concrete after fire is modified according to the material property test.Then,the modified material constitutive relation model is applied to the numerical simulation of specimens.The failure mode of the finite element model of the specimen is approximate to the failure mode after the test,and the calculated results of the load-displacement curve are in good agreement with the test results.The maximum temperature experienced by the specimen has a great effect on the residual capacity.

关 键 词：中空夹层钢管混凝土柱 超高强混凝土 轴压试验 火灾后 破坏模式 

分 类 号：TU398[建筑科学—结构工程]