门式刚架轻钢厂房屋盖竖向风振等效静力风荷载研究

EFFECTIVE STATIC WIND LOAD FOR THE ROOF OF LIGHT-WEIGHT STEEL STUCTURE WITH GABLE FRAMES DUE TO VERTICAL WIND

轻型门式钢架结构由于具有质量轻、柔性大、阻尼小的特性,使得其比常见的低矮建筑对风荷载更为敏感。目前分析低矮房屋背景分量等效静力风荷载较好的方法是荷载响应相关方法(LRC法),但是由于其具有计算繁琐、与响应位置和类型较复杂等不足而难于直接应用于实际工程。该文应用一种简化的LRC法-荷载升力相关法(LLC法)求解门式刚架结构的背景分量等效风荷载。结合具体的工程算例,采用有限元软件建立不同屋盖跨度变截面门式刚架结构的实体模型,选取檩条与屋架的交接处作为施加脉动风荷载的节点,求解结构在最大升力情况下的等效静力风荷载,并将结果与按荷载规范计算所得风载进行对比分析。研究表明:门式刚架轻钢厂房结构受竖向脉动风的影响不容忽视,在设计中需予以考虑。

A portal frame structure is more sensitive to wind loads than the common low-rise buildings, because of its light weight, great flexibility, and lower damping characters. At present, one of the best methods to analyze the background effective static load of the common low-rise building is Load-Response-Correlation method （LRC method）. However, it is difficult to be directly applied to engineering practice by the insufficient in its complicated computation, complex response to location and type. This paper used a simplified LRC method- Load-Lift-Correlation method （LLC method） to solve the background effective static load of the light-weight steel structure. Combining with a specific project example, we used the finite element software to establish different roof span portal frame structure models, selected the junction of the purline and roof as the research node of reflecting vertical wind-induced vibration response, solved the background effective static load of the light-weight steel structure in the maximum lift, and contrasted with the load which analyzed by the load code for the design of building structures. Research shows that, the effect of vertical wind-induced vibration to the portal frame structure cannot be ignored and should be taken into account in the design.