Fatigue problems of high-rise towers,induced by along-wind vibration in extreme conditions of frequent strong winds (or typhoons)for coastal areas,are not considered in current design standards. Therefore,the along-wind time-history samples and wind-induced responses for a typical high-rise tower were simulated at various wind speeds by using MATLAB and ANSYS software,based on harmony superposition method,random vibration theory and frequency characteristic of fluctuating wind velocity. Stress amplitudes and cycles at the crucial point were counted by using rain-flow method.And fatigue life was estimated based on Miner fatigue cumulative damage theory.It is indicated that the simulated time-history curves of fluctuating wind velocity effectively described the actual characteristic of wind veloci-ty,examined by using power spectrum and related function;the maximum value and root-mean-square of wind -induced time -history responses for the tower exponentially increased with increasing wind speed,and the former was slightly larger than that in JB/T 4710-2005;the fatigue damage of this tower induced by along-wind vibration was not significant below the strong gale,while several strong typhoons would lead to obvious fatigue damage or even failure.This paper provides some insight into optimal design of high-rise towers in windy areas.%针对现行设计标准中未曾考虑沿海等地区强风(或台风)频发的极端条件下,顺风向振动可能导致的高耸塔器疲劳问题,基于谐波叠加法、随机振动理论及脉动风速频域规律,利用MATLAB和ANSYS软件模拟,获得了某一典型高耸塔器在各风速下的顺风向脉动风速时程样本及风振时程响应,采用雨流法统计了危险点应力幅值与循环周次,根据Miner疲劳累积损伤理论估算了疲劳寿命。结果表明:模拟脉动风速时程曲线经自功率谱和自相关函数检验可较好地反映真实风速特征;随着风速的增加,塔器风振时程响应的最大值和均方根呈指数关系增大,且前者略大于JB/T 4710-2005中的计算结果;9级风以下顺风向振动引起的塔器疲劳损伤不大,但多次较强台风作用可能会导致明显的疲劳损伤甚至失效。此研究旨在为多风地区高耸塔器的合理设计提供参考。
展开▼