援莫桑比克国家体育场风荷载相干函数与风致响应分析

援莫桑比克国家体育场屋盖为典型的钢结构大跨度悬挑屋盖,风荷载为其结构设计的主要控制荷载.通过刚性模型表面测压风洞试验,得到了体育场屋盖的风压时程,并以此为基础,计算了屋盖表面各测点的风荷载相干函数,分析了屋盖结构不同区域测点之间表面风荷载相干函数的变化规律.另外,利用结构有限元模型,使用频域方法计算得到了结构的位移与内力均方根响应,分析了屋盖表面风荷载相干函数对风致位移和内力响应的影响以及振型数量和振型交叉项对屋盖风致位移和内力响应的贡献.结果分析表明,在进行结构风致响应计算时,不考虑各测点之间的相干函数,会低估结构的风振响应,不考虑结构振型交叉项的影响,也会导致计算结果较大的误差.

Analysis of coherence function of wind loads and wind-induced responses of National Stadium of aid Mozambique

National Stadium roof of aid Mozambique is typical steel large cantilevered roof;and wind loads are the main control loads of these structures.By rigid model wind tunnel tests of multi-point synchronous pressure,the wind pressure time series of stadium roof are obtained.Then based on the test results,the wind pressure coherence functions are evaluated;and the change rule of the coherence of the wind pressure in different regions is analyzed.On the other hand,the wind-induced root mean square(RMS)displacement and internal force responses are evaluated through the finite element model of the roof by using the method of frequency domain.In the mean time,influence of the coherence function of the roof,as well as contributions of the number of mode shape and the correlation between the modes to wind-induced displacement and internal force responses of roof,are analyzed.The analytical results show that the wind-induced dynamic responses of the roof would be underestimated when the wind pressure coherence is ignored;and the error of the results would be large if the correlation between the modes is neglected.