有初应力的钢管混凝土格构柱轴压试验研究

为了研究初应力对钢管混凝土格构柱受力性能的影响，进行了有初应力的钢管混凝土格构柱的轴压试验研究，对初应力的施加方式、荷载 位移全过程曲线、柱肢套箍效应等进行分析。研究结果表明：初应力的存在会使钢管混凝土格构柱弹塑性阶段提前出现，试件的组合刚度下降、局部屈曲明显；同时，初应力影响组合材料的泊松比发展历程，使得套箍作用出现推迟，从而影响套箍作用的充分发挥，并最终降低试件的承载力。初应力对缀管受力性能的影响不大，缀管的受力处于弹性工作阶段。

Experimental study on influence of initial stress on concrete filled steel tubular latticed columns subjected to axial load

In order to study the influence of the initial stress on the mechanical performance of concrete filled steel tubular (CFST) latticed columns, axial loading test of CFST latticed columns with initial stress was conducted. The test setup for applying initial stress, the curves of load vs. deformation as well as the hooping effect were analyzed. The results indicate that the CFST columns with initial stress have smaller combined stiffness and ultimate load-carrying capacity as compared with CFST columns without initial stress. Furthermore, the presence of initial stress will advance the coming of plastic phase, delay the appearance of hooping effect and weaken its benefit, which decreases the ultimate load-carrying capacity. Nevertheless, the mechanical behavior of lacing tubes -doesn’t-vary with the initial stress and all the lacing tubes are in the elastic phase during the testing.