基于风压分布特性的折叠网壳结构形状优化研究

Folding reticulated shell structure shape optimization based on wind pressure distribution characteristics

针对风敏感结构折叠网壳存在抗风不利区域和风压梯度变化较大的力学行为,为优化其在风荷载作用下的表面风压分布,降低结构的风致响应,基于流体动力学基本原理和大气边界层基本理论,运用Fluent软件对折叠网壳结构风压分布进行数值模拟的基础性研究,对比风洞试验结果,确定复杂体型结构数值模拟的计算域尺寸、计算域离散和湍流模型等关键参数的选取。在此基础上对8种折叠网壳结构形状优化方案进行分析,得到其分区体型系数和体型系数的标准差,对比结构初始形态表面风压,最终得到具有良好抗风性能的最优方案,化解了结构的不利风压分布。结果表明,CFD数值分析技术能够有效地解决风敏感结构在风荷载作用下的形状优化问题,为结构体型优化和研发新型野营房屋提供了一个设计方法和理论依据。

As a kind of wind-sensitive structure, the folding reticulated shell has mechanical behaviors of weak area to wind-resistance and large wind pressure gradient. To optimize the superficial wind pressure distribution and reduce the wind-induced responses for folding reticulated shell,a fundamental study was conducted by using the software FLUENT, which was based on the fluid dynamic theory and the atmospheric boundary layer theory. According to the wind tunnel test results,some key parameters were discussed including the computational domain size, the computational domain discrete and the turbulence model. On this basis, 8 shape optimization schemes of folding reticulated shell were analyzed and the partition shape coefficients and their standard deviation were obtained accordingly. Through comparing with the initial surface wind pressure of the structure,an optimal scheme was gotten finally,which has good performance of wind-resistance and can relieve the adverse distribution of wind pressure effectively. The results indicate that the CFD numerical analysis method is applicable in the shape optimization of wind-sensitive structure, and it provides an effective method for the design of new camping houses.