台风作用下网壳结构动力失效研究

发布时间：2018-01-13 20:30

本文关键词：台风作用下网壳结构动力失效研究　出处：《浙江大学》2016年硕士论文　论文类型：学位论文

【摘要】：大跨空间结构多用于体育场馆、交通建筑、会展中心等大型公共建筑,这类结构的重要性不言而喻,一旦破坏或失效会给社会生产和人民生命安全带来重大损失,同时也会造成较坏的社会影响。我国每年都会遭受台风袭击,大跨度结构在风振作用下破坏的案例时有发生。因此研究大跨度结构在台风作用下的动力失效具有重要意义。本文基于Yan Meng台风模型,确定了影响台风风场的关键参数,根据1949-2014年间西北太平洋热带气旋实测数据,用模拟圆法分析了台风关键参数的最优概率模型。依据台风关键参数的最优概率模型,用随机抽样法随机抽取了10000组台风,与实测热带气旋极值风速进行拟合,得到台风平均风剖面指数。用FLUENT软件数值模拟了常规风场和台风风场下球面网壳和顶部开口网壳表面风压特性。表明球面网壳在常规风场和台风风场下风压规律相似,但台风风场下网壳表面的风压系数要大于常规风场下的风压系数。矢跨比为1/8时,两类风场屋盖表面风压以负压为主,负压最大值出现在横风向边缘附近,在垂直风运动方向,网壳边缘的风压系数要大于中间区域的风压系数。分别依据Davenport谱和Von Karman谱,采用谐波合成法,用MATLAB模拟了球面网壳结构在常规风场和台风风场下表面各点的风速时程,并与目标谱进行了对比,验证了常规风场和台风风场各自风速谱的正确性。对比了常规风场和台风风场下网壳结构和弦支网壳结构的动力效应,得出相对于常规风场,台风风场作用下网壳和弦支网壳结构的位移响应和均方差更大,且在台风作用下,弦支网壳结构的最大位移出现在与内环撑杆连接的上部网壳节点处。以最大位移和塑性杆件比例为指标提出了台风作用下网壳结构动力失效判定准则；以节点最大位移、塑性杆件比例和索是否松弛为指标提出了台风作用下弦支网壳结构动力失效判定准则。并通过算例验证了该判定准则的适用性。
[Abstract]:Large span space structures are used in large public buildings such as stadiums, traffic buildings, convention and exhibition centers, etc. The importance of such structures is self-evident. Once the damage or failure will bring great loss to social production and people's life and safety, it will also cause a bad social impact. China will be hit by typhoons every year. There are some cases of long-span structures damaged under wind-induced vibration. Therefore, it is important to study the dynamic failure of long-span structures under typhoon. This paper is based on Yan Meng typhoon model. The key parameters affecting typhoon wind field are determined, and the measured data of tropical cyclones in the Northwest Pacific Ocean from 1949 to 2014 are analyzed. According to the optimal probability model of typhoon key parameters, 10000 groups of typhoons were randomly selected by random sampling method. Fitting with the measured extreme wind speed of tropical cyclone. The mean wind profile index of typhoon is obtained. The surface pressure characteristics of spherical latticed shell and open top latticed shell under conventional wind field and typhoon wind field are numerically simulated by FLUENT software. It is shown that spherical reticulated shell is in conventional wind field and typhoon wind field. The law of downwind pressure is similar. However, the wind pressure coefficient of the reticulated shell surface under typhoon wind field is larger than that under the conventional wind field. When the rise-span ratio is 1/8, the negative pressure on the roof surface of the two kinds of wind field is mainly negative pressure, and the maximum negative pressure appears near the edge of the cross wind direction. In the vertical direction of wind motion, the wind pressure coefficient at the edge of the reticulated shell is larger than that in the middle region. According to the Davenport spectrum and the Von Karman spectrum, the harmonic synthesis method is adopted. The wind time history of spherical reticulated shell structure under conventional wind field and typhoon wind field is simulated by MATLAB and compared with the target spectrum. The validity of wind speed spectrum of conventional wind field and typhoon wind field is verified. The dynamic effects of reticulated shell structure and chord branch latticed shell structure under conventional wind field and typhoon wind field are compared and compared with conventional wind field. The displacement response and mean square deviation of the latticed shell and chord branch latticed shell structure under typhoon wind field are larger than those of typhoon. The maximum displacement of chord supported latticed shell structure appears at the upper reticulated shell node connected with inner ring bracing rod. The criterion for determining dynamic failure of latticed shell structure under typhoon action is proposed based on the maximum displacement and plastic member ratio. A criterion for determining the dynamic failure of chord latticed shell structures under typhoon action is presented based on the maximum displacement of nodes, the proportion of plastic members and the relaxation of cables. The applicability of the criterion is verified by an example.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU399

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