风雪共同作用下门式刚架厂房的动力稳定

Dynamic Instability of Light-weight Steel Structures with Portal Frames Under Wind and Snow Loads

摘要:

结合数值计算和风洞试验,研究门式刚架轻型钢结构厂房在风雪耦合作用下的动力稳定性.通过CFD（计算流体动力学）方法,模拟厂房屋面上的风雪耦合作用,由风洞试验获得厂房表面的非定常气动力,然后将门式刚架厂房作为空间刚架体系,利用Budiansky-Roth准则研究其动力稳定.研究表明,数值模拟得到的积雪漂移现象与屋面上气流的运动规律基本一致,不均匀积雪使门式刚架厂房在风场中的动力稳定性显著降低.

关键词:风雪共同作用; 门式刚架; 轻型钢结构厂房; 动力稳定; CFD方法; 风洞试验

Abstract:

The dynamic instability of light-weight steel structures with portal frames under coupled wind and snow loads is studied by numerical simulation and wind tunnel tests.Coupled action between wind and snow is simulated by computational fluid dynamics(CFD)method and the unsteady aerodynamic forces on the structure are obtained by wind tunnel test.Then,the structure is studied as a spatial portal frame on its dynamic instability by the Budiansky-Roth criterion.The results show that simulated snow-drifting on the roof is consistent with the movement rule of airflow near the roof.Non-uniform snow distribution can decrease the dynamic stability of the structure simultaneously under wind actions.

Key words:wind and snow loads; portal frames; light-weight steel structures; dynamic instability; computational fluid dynamics(CFD); wind tunnel tests