基于CFD模拟的钢管桁主梁气动特性研究

Study on Aerodynamic Characteristics of Steel Tube Truss Girder Based on CFD Simulation

摘要:

基于计算流体力学方法，以深圳市拟建山谷沟壑处景观桥为研究对象，建立三维仿真节段模型进行气动性能研究。首先研究节段桁架模型在对称边界条件下的合理性，得出可以利用节段模型来代替三维整桥进行数值模拟，然后通过比较三维整桥模拟与国内现行规范中桁架桥气动参数选取方法，做出检验并提出改进建议，以桁架桥结构截面的外轮廓和实面积比作为控制条件建立二维等效模型，采用4种二维圆管桁主梁CFD计算简化模型，并计算了在-5°、-3°、0°、3°、5°攻角情况下的桁架桥梁静力三分力系数，同时基于非定常时程曲线，对4种二维等效模型附近的空间流场结构，涡振性能差异进行了对比。

Abstract:

In order to study the influence rule of chloridion erosion on the thickness of the protective layer of concrete piers, the influence coefficient of chloride ion penetration resistance and protective layer thickness of concrete with different mineral admixtures and different admixture ratios are analyzed. The study shows that the replacement of cement with a certain proportion of mineral admixtures can effectively improve the chloridion resistance of concrete and reduce the influence coefficient on the protective layer thickness.