开敞式叉筒网壳风场数值模拟与受力分析

Numerical simulation and mechanics analysis of wind-loading on open latticed groined barrel vault

针对国家现行《建筑结构荷载规范》缺乏复杂形体结构净风压体型系数的相关规范的问题,应用标准kε紊流封闭模型,采用数值风洞技术对开敞式叉筒网壳在多角度风场作用下结构表面的风压分布进行了数值模拟,获得了该类网壳的净风压体型系数.研究表明采用数值风洞技术对复杂形体结构的流场进行计算机数值模拟的方法是可行的,这为风压分布及大小取值提供了一种非实验性的、低成本的取值方法.力学分析结果表明,风对开敞式叉筒网壳的最大负压主要集中在脊线附近的边缘部位,脊线附近边缘以及谷线交叉拱是结构设计的重点.

Wind load has great effect on the mechamics behavior of open-wide-span spatial structure with complex shape. Numerical wind trnnel technology based on computational fluid dynamics is an effective method for the study of the wind field. Wind pressure distribution under the action of multi-angle wind load was simulated based on the standard kε closure turbulence model, and the shape coefficients of net wind pressure were obtained. Calculation results indicate that the major negative presssure of this kind of structure bearing wind load mainly concentrates on the ridge; the ridge brink and the groined arches of valley are the most important regions for structure design. There is a lack of net wind pressure coefficients for abnormity structures on actual Chinese building strutures design loading standard. Based on the standard kε closure turbulence model of computational fluid dynamics, the wind pressure distribution of open latticed groined barrel vault under action of multi-angle wind load was simulated by numerical wind tunnel technique, and the shape coefficients of net wind pressure were obtained. It is indicated that the numerical simulation of wind pressure by numerical wind tunnel technique is feasible, which is a non-experimental and cheap method and useful for building structures design. The mechanics analysis indicates that the largest negative wind pressure of open latticed groined barrel vault mainly concentrates on the ridge brink of the structures, and that the ridge brinks and the groined arches of valley are the most important regions for structure design.