变截面高层筒体结构的水平振动

HORIZONTAL VIBRATION ANALYSIS OF TALL TUBULAR BUILDING STRUCTURES WITH STEPPED CROSS SECTIONS

本文用有限元线法对变截面的高层筒体结构的动力特性进行分析.先用分段连续化方法将实际框筒结构等效为变截面的正交各向异性折板结构;将结构沿一个方向(横向)半离散化,取结线位移为基本未知函数,通过势能驻值原理,建立半解析的振动微分方程组;然后用常微分方程求解器COLSYS求解频率和振型.为多维结构的振动分析提供了一个半解析的新解法.

In this paper, horizontal vibration analysis of tall tubular building structures with stepped cross-sections by use of the Finite Element Method of Lines ( FEMOL ) are presented. The framed tubes are firstly replaced by equivalent orthotropic continua. Then the continuum models are analyzed by applying FEMOL, in which the nodal line displacements are taken as primary unknown functions. The Minimum Potential Energy Principles are used to set up the vibrational differential equations. Through some transformations, the Ordinary Differential Equations ( ODE ) of horizontal vibration are directly solved by ODE Solver, which is a general purpose program developed for solving various ODE including eigenproblems. Then the natural frequences and normal modes are obtained. A new semi-analytic method for vibrational analysis of multi-dimensional structures is presented.