摘要
在龙卷风气象观测记录和三维龙卷风风场模型的基础上,推导极值Ⅲ型龙卷风强度分布函数并结合CFD方法建立龙卷风随机荷载模型。以核电常规岛主厂房为计算模型,采用谱随机有限元法,考虑移动龙卷风荷载和结构参数的不确定性,对结构进行动力响应和可靠度分析。分析结果表明:龙卷风中心距离结构边缘60m以上时,几乎对结构无影响,一旦接近建筑物,在短时间内会对结构造成猛烈的冲击;龙卷风对结构主要产生指向龙卷风中心的侧向推动作用;当龙卷风即将接近厂房中心时,结构可靠度最低,当龙卷风中心与厂房中心重合时,结构可靠度较高;谱随机有限元法的分析结果稳定可靠,使用时应对变异性起控制作用的随机变量进行高精度离散和表达。
Based on tornadic meteorological observation records and 3D tornado wind field model,a tornado intensity distribution of extreme value type Ⅲ was derived and a random load model of tornado was established by combining with CFD method. With the uncertainty of moving tornado load and structural parameters taken into account and the conventional island main building as the computational model,the dynamic response and reliability analysis of structure was carried out by using the spectral stochastic finite element method( SSFEM). The results show that when the distance between tornado center and the edge of the building is more than 60 m,tornado almost has no effect on structure. While tornado causes severe impact on structure in a short time,once it is getting close to building,since tornado load produces tornado center-pointing lateral pushing force on structure. The reliability of the main building is relatively low when tornado is moving closer to the structural center,while the reliability is fairly high when tornado center is located exactly at the center of main building. The SSFEM analysis is stable and reliable,but in applications the stochastic variables which control the variability of the whole system should be discretized with high precision and represented.
出处
《土木工程学报》
EI
CSCD
北大核心
2015年第4期42-51,共10页
China Civil Engineering Journal
