大型钢管输电塔非线性地震反应研究

Research on Nonlinear Seismic Responses of a Large Scale Steel Tube Transmission Tower

研究了某大型钢管输电塔的非线性地震反应问题。首先,建立了钢管输电杆塔的有限元模型,建立了输电杆塔在地震激励作用下的运动方程和非线性地震反应计算方法。以某实际输电杆塔为工程背景,研究了输电杆塔的线性和非线性地震反应特点和规律,并进一步地对比了线性地震反应和非线性地震反应的差异。结果表明,输电杆塔由多根杆件所组成,在强烈地震作用下结构不同位置表现出了不同的地震反应特点。地震激励沿出平面方向作用的结构反应略大于沿在平面方向作用的地震反应,杆塔结构上部表现出了一定程度的鞭梢效应。考虑几何非线性效应的分析结果比线弹性地震反应的结果略大,考虑双重非线性效应的结果则比只考虑材料非线性效应的结果略大。

The nonlinear seismic responses of a large scale steel tube transmission tower were investigated. Firstly,the finite element model of a transmission tower was constructed,and the motion equations and the calculated methods of nonlinear seismic response of the transmission tower under the effect of earthquake were developed. A real transmission tower in China was taken as an example to examine the characteristics of the seismic responses of transmission towers and to study the differences between the linear and nonlinear seismic responses. The experimental results indicated that a transmission tower was consisted of many members and their seismic responses were different to some extent. The peak responses under in-plane earthquake are slightly larger than that under out-of-plane earthquake. The whiplash effects on top of the transmission tower can be observed in comparison with other parts of the tower. It is found that the peak seismic responses with geometric nonlinear effects are slightly larger than that with linear seismic responses. In addition,the dual nonlinear seismic responses are also larger than that only with material nonlinear effects.