轴压比对圆中空夹层钢管混凝土抗撞性能的影响分析

Influence analysis of axial load ratio on impact resistance of circular concrete filled double-skin steel tubular

轴压比是影响圆中空夹层钢管混凝土构件抗撞性能的一个重要参数,因此,在前期试验研究基础上,采用ABAQUS建立了圆中空夹层钢管混凝土构件在侧向撞击和轴力荷载耦合作用下的有限元分析模型,研究了不同轴压比下构件抗撞工作机理,并以名义截面含钢率、空心率与材料强度为主要参数,重点分析了轴压比对构件抗撞性能的影响。结果表明:在侧向撞击和轴力荷载耦合作用下构件主要发生受弯破坏,外钢管与混凝土的塑性变形是构件的主要耗能机制;当轴压比从0增大到0.5时,构件的抗撞性能先增强后减弱;随着构件名义截面含钢率、空心率和外钢管屈服强度的增大及混凝土强度的减小,轴压比对构件抗撞性能的有利影响范围分别减小约75%、57%、15%和18%。

Axial load ratio is an important parameter that affects the impact resistance of circular concrete filled double-skin steel tubular(CFDST)members.Therefore,based on preliminary experiments,finite element analysis(FEA)model of CFDST combined lateral impact and axial load was established using ABAQUS.The working mechanism of CFDST members with different axial load ratio under impact load was investigated.With nominal cross-sectional steel ratio,hollow ratio and material strength as the main parameters,the influence of axial load ratio on the impact resistance was emphasisly analyzed.The results show that under combined lateral impact and axial load,the members failed in flexural mode.The main energy dissipation mechanism of members was the plastic deformation of outer steel tube and concrete.As the axial load ratio increased from 0 to 0.5,the impact resistance of members increased first and then decreased.With the increase of nominal cross-sectional steel ratio,hollow ratio and yield strength of external steel tube,and the decrease of concrete strength,the favorable influence range of axial load ratio on the impact resistance of members decrease by about 75%,57%,15%and 18%respectively.