悬挂网壳结构风压分布的环境影响因素研究

Study on Environmental Factors Affecting Wind Pressure Distribution of Suspended Reticulated Shell Structure

为了研究环境因素对机场大跨度悬挂网壳结构风荷载分布特性的影响,通过在SST k-ω湍流模型的基础上结合CFD技术对悬挂网格结构进行风洞试验数值模拟,验证了数值模拟方法的准确性并对比研究了周边建筑、围护结构、地势高低与支撑结构等不同环境因素下悬挂网壳风荷载分布规律,发现:周边建筑可以对风荷载起到遮挡效果,降低网壳表面风压,遮挡效果随着夹角的增大逐渐衰弱;有围护结构的封闭式悬挂网壳较开放式悬挂网壳存在更大的风压梯度,在一定程度上可以提高结构承风能力,但对于非规则网壳结构无规律可循,故在实际工程中,需根据情况具体分析;随着悬挂网壳结构所处地势高度的增加,其受到风压的影响程度有一定的增幅,但当地势变化差异不大时,结构受风扰动不明显;拱梁对结构表面风压分布趋势影响较小,对风荷载起到了遮挡作用,可以降低悬挂网壳结构风压系数值。

In order to study the influence of environmental factors on the wind load distribution characteristics of long-span suspended reticulated shell structure in airport,based on SST k-ωRayleigh model and CFD technology,the wind tunnel test numerical simulation of the suspended reticulated shell structure was carried out,and the accuracy of the numerical simulation method was verified.The wind load distribution law of the suspended reticulated shell under different environmental factors such as surrounding buildings,enclosure structures,topography and supporting structures was comparatively studied.It is found that the surrounding buildings can shield the wind load and reduce the wind pressure on the surface of the reticulated shell,and the shielding effect gradually weakens with the increase of the included angle.Compared with the open suspended reticulated shell,the closed suspended reticulated shell with enclosure structure has larger wind pressure gradient,which can improve the wind bearing capacity of the structure to a certain extent.However,there is no rule for irregular reticulated shell structure,so it needs to be analyzed according to the actual situation.With the increase of the terrain height of the suspended reticulated shell structure,the influence degree of wind pressure increases to a certain extent,but when the terrain changes little,the structure is not obviously disturbed by wind.The arch has little influence on the distribution trend of wind pressure on the structure surface,plays a role in shielding the wind load,and can reduce the wind pressure coefficient of the suspended reticulated shell structure.