地面角钢塔及楼顶角钢塔的基本自振周期研究

RESEARCH ON BASIC NATURAL VIBRATION PERIOD OF GROUND AND ROOF ANGLE STEEL TOWER

角钢塔基本自振周期计算影响到风荷载及地震作用计算,自振周期与结构质量和刚度的分布情况相关。通过求解刚度矩阵和质量矩阵可得到角钢塔的自振周期,计算时应考虑角钢塔平台的设置位置、数量以及下部建筑物的影响。为此建立有限元模型,计算分析各种情况下的角钢塔自振周期。计算结果表明,顶部平台对自振周期影响很大,且平台高度越大对自振周期影响权重越大;下部混凝土建筑对自振周期影响很大,自振周期计算时应考虑整体结构的影响。混凝土建筑物高度大于角钢塔时,可直接选取混凝土结构自振周期作为角钢塔自振周期。根据计算结果拟合得到的简化公式,对角钢塔的设计具有参考价值。

The basic natural vibration period of angle steel tower affect the wind load and earthquake action calculation,since natural vibration period related to the distribution of mass and stiffness of structure.To obtain the basic natural vibration period of angle steel tower by solving stiffness matrix and mass matrix,it should be considered that quantity and location of angle steel tower platform and the influence of the lower reinforced concrete building in its calculation.The basic natural vibration period of various cases of angle steel tower was analyzed by establishing finite element model.The calculation results show that the top of the platform has a great effect on natural vibration period,and the larger the platform height,the greater the effects on natural vibration period. Lower concrete building had a great influence on natural vibration period,when calculating the natural vibration period the influence of the integral structure should be also taken into account.When concrete building height is greater than the angle steel tower,the natural vibration period of the structure can be directly selected as that of the angle steel tower.The simplified formula fit by calculation results can provide reference for the design of angle steel tower.