钢管混凝土推出试验的力学行为分析

摘要

目的 为了提高钢管混凝土复合结构的承载能力,研究一种钢管混凝土推出试验及其力学行为的分析方法.方法 利用微段分析法,得到在线弹性范围内,钢管混凝土粘接层粘接切应力近似微分方程.结果 给出了给定边界条件下粘接切应力方程.推导了核心混凝土轴力与轴向位移、钢管轴力与轴向位移以及核心混凝土与钢管相对轴向位移方程.粘接切应力方程为双曲正弦函数,在加载端,粘接切应力发生应力集中,应力集中的程度随切变模量的增大而减弱.轴向相对位移在加载端为正,随着加载端的远离,钢管轴力逐渐增大的缘故,轴向相对位移却可能为负.结论 利用提出的钢管混凝土推出试验可以测量钢管混凝土之间粘接层的力学性能,钢管混凝土粘接层受剪力学行为分析方法为模拟钢管混凝土之间滑移现象提供理论基础.%A new push-out test of concrete-filled steel tube(CFST)is designed and the mechanical behavior analysis method for the push-out test is presented in order to enhance loading ability of CFST composite structures. Approximately differential equation of adhesive shearing stress in adhesive layer between concrete and steel under linear elasticity condition is derived and adhesive shearing stress equation for given boundary conditions is solved out. The shearing stress equation is sine hyperbola function equations of axial force and displacement for the core concrete and the tube are given,and the relative displacement between concrete and tube is also derived. It is shown that the concentration of adhesive shearing stress at the loading-end takes place. The strength of the stress concentration decreases with increasing of the shearing modulus. The relative displacement is positive at the loading-end,however,may be it is negative far from the loading-end because the axial force in the tube increases.