基于多相流理论的风雨共同作用下鞍形膜结构响应分析

THE SADDLE MEMBRANE STRUCTURE RESPONSE ANALYSIS UNDER THE SIMULTANEOUS ACTIONS OF WIND AND RAIN BASED ON MULTIPHASE FLOW THEORY

膜结构重量轻、跨度大、自振频率低,对风敏感,因此膜结构抗风设计是一个必须考虑的因素。但在实际中,大风暴雨往往相携而来,仅考虑风荷载对设计已经不足,由此而出现的事故也有发生,因此风雨共同作用下膜结构的设计成为一个现实问题。以此为背景研究风雨共同作用下鞍形膜结构的响应,基于多相流理论的欧拉-欧拉模型,考虑降雨强度、雨滴直径、体积分数和末速度等对风荷载的影响,取4种风向角,3种不同降雨强度和3种不同风速,对比风速变化、雨强变化等对鞍形膜结构响应的影响。结果表明：风雨共同作用时鞍形膜结构位移、应力显著增加;45°风向角下结构稳定性较差。

Membrane structure has features of light weight,long span,low frequency,so and it is sensitive to wind and the wind resistance design is necessary. In practice,the storm wind and rainstorms often come together. Only considering the wind load,the design of membrane can not meet the requirements. Therefore,based on this background,an optimized design of membrane structure which considering the simultaneous actions of wind and rain should be proposed. In the paper,using the Eulerian-Eulerian model according to multiphase flow theory,the saddle membrane structure response analysis under the simultaneous actions of wind and rain was conducted. Considering the effects of rainfall intensity,raindrop diameter,volume fraction,and end velocity on wind load,and taking four wind direction angles,three rainfall intensities,and three wind speeds,the influence of changes in wind speed and rain intensity on the saddle-shaped membrane structure response were compared. The paper could provide reference for membrane structure design. The results showed that the displacement and stress of saddle membrane increase significantly when wind and rain work together and the stability of structure is poor at 45 owind direction.