Q690高强钢焊接箱形轴压构件整体稳定研究及设计建议

Overall buckling behavior and design of Q690 high-strength steel welded box-columns subjected to axial compression

为研究Q690高强钢焊接箱形轴心受压构件的整体稳定性能,给出适合该类构件的设计建议,通过对3根Q690焊接箱形截面试件的残余应力试验,得到了箱形截面的残余应力分布模型。设计并制作了5根Q690焊接箱形柱,并对其两端铰支条件下进行了轴压试验研究,试验前分别对试件的几何初始缺陷和初始偏心均进行了测量。轴压试验中,所有试件破坏形式均为整体失稳破坏。基于试验结果,分析了该试件的整体稳定性能,采用直接分析法建立了数值模型,并校验了数值模型的准确性。同时,采用该数值模型对箱形轴压构件进行了参数分析,基于试验和参数分析结果,给出了Q690焊接箱形轴压构件的一阶弹性设计建议。

The main objective was to investigate the overall buckling behavior of Q690 high-strength steel welded box columns and provide some recommendations for design of such columns. The residual stress distribution of three box- section specimens made of Q690 high-strength steel was measured, and the simplified residual stress models related to such specimens were proposed. Moreover, five welded box columns with the Q690 steel grade were prepared. An experimental study on the overall buckling behavior of such pin-ended columns under axial compression was carried out. Before the experiment, the initial crookedness and loading eccentricity of the specimens were measured and recorded. The experiment shows that the failure modes of all specimens are overall buckling. Based on the experimental results, the overall buckling behavior of the axially loaded high-strength steel columns were discussed. With the direct analysis method, the numerical model was established and verified. Subsequently, parametric study of box columns is conducted by applying the numerical model. Based on the results of the experiment and parametric study, some proposals for design of Q690 steel welded box columns are given.