高耸烟囱结构在地震作用下的动力时程分析*
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(1 武汉理工大学土木工程与建筑学院，武汉 430070；2 武汉理工大设计研究院有限公司，武汉 430070)[摘 要] 通过Rayleigh法对高耸烟囱结构进行振动分析，采用ANSYS建立高耸烟囱有限元模型，分析混凝土烟囱在水平和竖向地震共同作用下的地震响应。研究表明：将烟囱等分布柔性参数体系的运动近似为单自由度建立运动方程，采用Rayleigh法并假设结构形状函数对分布柔度体系计算自振频率是合理的；不同的结构高度、筒径尺寸对结构水平和竖向振动动力特性影响显著，结构竖向振动周期短，接近高频振动，与结构的高度呈线性变化；随着结构高度的增加，结构顶点位移呈逐渐增加趋势，结构达到位移幅值时，烟囱根部等效应力随着结构高度的增加显著增大。[关键词] Rayleigh 法; 地震响应; 分布柔度参数体系; 等效应力中图分类号：TU 文献标识码：A 文章编号：1002-848X(2013)S2-0390-05Dynamic time-history analysis on stack-like structure under earthquake actionsLiu Jixiong1, Huang Jun1,2, Dai Shaobin2（1 School of Civil Engineering and Architecture of Wuhan University of Technology，Wuhan 430070, China; 2 Architecture Design &Research Institiue of Wuhan University of Technology, Wuhan 430070, China)Abstract: Through Rayleigh method, the vibration analysis of stack-like structure was conducted, using ANSYS to establish the finite element model of high chimney, the earthquake response of concrete chimney was studied under the combined effect of the horizontal and vertical earthquake. The results indicate that approximating the movement of chimney and other distributed flexible parameter system as a single degree of freedom to establish a motion equation, adopting Rayleigh method and assuming the structural shape function to calculate the natural frequency is reasonable. Different structure height and cylinder diameter have a significant impact on the dynamic characteristics of the horizontal and vertical vibration. Structural vertical cycle is short, close to the high -frequency vibration; it changes with height of the structure linearly. With the increase of the height of structure, vertex displacement increases gradually. When the displacement reaches the displacement amplitude, equivalent stress increases significantly.Keywords: Rayleigh method;earthquake response;distributed flexible parameter system
