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河南广播电视发射塔外塔柱采用异型大直径钢管,截面由三段直边和三段圆弧板组合而成,其径厚比已超过现行《钢结构设计规范》对圆钢管径厚比的限值,其承载力与管壁不同的加劲方法有关。分别采用内加劲肋和内桁架加劲两种方法对管壁进行内加劲可提高管壁的局部稳定性,从而提高构件的极限承载力。通过对两种加劲方法以及无加劲肋三种类型截面塔柱的缩尺试验研究和有限元模拟分析,有限元计算结果与试验实测结果吻合较好。研究表明:设计荷载作用下,三种形式截面均全截面处于弹性工作状态,具有足够的强度和刚度。对管壁采用内加劲肋方式处理后,截面承载能力提高20%左右,采用内桁架对管壁进行处理也可改善截面的应力分布,但在设计荷载作用下的效果并不显著。建议设计中采用内加劲肋对管壁加劲,提高构件的安全储备。
Henan radio and television tower outside the tower using special-shaped large-diameter steel pipe, cross-section by the three straight-edge and three arc plates combination of its diameter ratio has exceeded the current “steel design code” on the diameter ratio of round steel pipe Limits, the bearing capacity and the wall of the different methods of stiffening. Internal stiffener and internal truss stiffener are respectively used for internal stiffener to increase the local stability of the pipe wall, so as to improve the ultimate bearing capacity of the component. The results of two kinds of stiffeners and three types of stiffeners without stiffeners are studied by scaling experiments and finite element analysis. The calculated results agree well with the experimental ones. The research shows that under the design load, the full cross-section of the three types of cross-section is in elastic working state, and has sufficient strength and rigidity. After the pipe wall is treated with internal stiffeners, the load carrying capacity of the cross section is increased by about 20%. The treatment of the pipe wall with the internal truss can also improve the stress distribution of the section, but the effect is not significant under the design load. It is suggested that the internal stiffener be used to stiffen the pipe wall in the design to improve the safety reserve of components.