大跨空间钢结构在露天日照作用下的热分析方法

Study on the Thermal Analysis Method of Large-span Spatial Steel Structure Under Sunshine

日照温度作用是大跨空间结构在露天施工过程中的主要作用之一,甚至成为结构施工的控制作用。由于受太阳辐射、阴影遮挡、大气温度变化、风速等多因素影响,其是一种随时间变化的非均匀温度作用。在实际工程应用中,日照温度作用尚没有较为成熟统一的计算方法。首先概述了3种数值分析方法,并分析其适用性和优缺点,重点探讨了热分析有限元法及基于ANSYS软件的建模方法;对比分析了目前重大工程中采用的设计简化方法,对计算参数进行论述;列举了国内外规范对于钢结构日照温度作用的相关规定,重点阐述我国最新《建筑结构荷载规范》GB50009—2012有关计算规定;最后介绍了目前最常用的减小或消除日照温度作用影响的施工措施。

Sunshine temperature load is one of the main loads in the open-air construction process of spatial steel structure, and even becomes the control load. It is a time-varying and non-uniform temperature load through the solar radiation, shade effect, atmospheric temperature changes, wind speed, etc. There is not yet standard calculation method for sunshine temperature load in engineering applications. This paper firstly introduces three numerical analysis methods, discusses the applicability, advantages and disadvantages of these methods, which focuses on the finite element method of thermal analysis and its modeling method with ANSYS software. And then the comparative analysis of the simple design method applied in the current major project is put forward, and the calculating parameters are discussed. The relevant rules in the domestic and international specifications are listed, and＇the corresponding rules in the newest one of Chinese Load code for the design of building structures GB50009--2012 are described in detail. Finally the most common construction measures that reduce or eliminate the effects of sunshine temperature load are presented.