最新开敞式拱形波纹屋盖体型系数研究

开敞式拱形波纹屋盖体型系数研究

开敞式拱形波纹钢屋盖的风压分布及体型系数研究

贾永新 , 张勇

（北京交通大学土木建筑工程学院，北京 100044）

摘要：利用CFD数值模拟技术，结合实际工程对建筑和结构各个方面的要求和限定，首先对开敞式拱形波纹钢屋盖下部支承结构的柱高和柱距两因素进行了变参数分析，从中可确认这两个参数对屋盖结构的风压分布影响不大。然后选定影响屋盖风压分布的三个主要参数：跨度、矢跨比和纵跨比，进行了三参数三水平正交试验分析。从大量的计算结果中分析整理，得出此类结构上风压的分布规律，即风压在上表面分布比较均匀，具体表现为在迎风面为压力，在拱顶处和背风面为吸力，风压等值线在四周边缘出现集中；而在下表面两端由于旋涡脱落出现两个负压区，整体上表现为正压力。进一步了明确对此类结构风压分布影响显著的参数为矢跨比。最后参照我国现行《建筑结构荷载规范》【1】的形式，给出了开敞式拱形波纹钢屋盖结构的风荷载体型系数，供设计施工人员参考使用。

关键词：拱型波纹钢屋盖结构；开敞式；正交分析；风压分布；体型系数

中图分类号：TU399 文献标识码：A

Study on wind pressure distribution and the shape coefficient of

open-style arched corrugated steel roof

JIA Yongxin, ZHANG Yong

（School of Civil Engineering and Architecture，Beijing Jiaotong University，

Beijing 100044，China）

Abstract: Considering all the engineering aspects of architecture and structure requirements and restrictions, firstly, two variable parameters of lower supporting part of open-style arched corrugated steel roof --column height and column spacing were analyzed by using the CFD numerical simulation technique. It is confirmed that the two parameters have little effect on the distribution of the roof's wind pressure; then select three other parameters ( span, rise-to-span ratio and length-to-span ratio) and adopt orthogonal test of three factors and three levels for the study; at last, analyzed and sorted the data, obtain the wind pressure distribution. The pressure distribution is uniform on the upper surface, the concrete expression as following: pressure in the windward, suction on the tope and at the back of the roof. Wind pressure contour appears concentrated around the edges; however, at the end of the lower surface appears two negative pressure zones due to the vortex shedding .But, from the global aspect, the lower surface shows as positive pressure; further study pointed out that rise-to-span ratio has significant effect on the wind pressure

图1 开敞式拱形波纹钢屋盖模型

Fig.1 The model of open-style arched corrugated steel roof

distribution; finally, reference to the China's current "Building Structural Load Code", gives the shape coefficient of such structure and provide a reference for the designer and construction stuff.

Keywords ：arched corrugated steel roof; open-type; orthogonal analysis; wind 0 引言 拱形波纹钢屋盖是一种冷弯薄壁轻钢结构，具有自重轻、刚度小、自振频率低等特点，加之这类结构多处于大气边界层中风速变化大、湍流度高的区域，因此对风荷载十分敏感。于2004年

颁布实施的《拱形波纹钢屋盖结构技术规程》【2】在总则中明确规定，该规

程仅适用于封闭式建筑的拱形波纹钢屋盖结构的设计，而对于目前工程中常见的下部支承结构不封闭的开敞式结构（图1），规程并没有给出具体的设计技术方法，究其根本原因在于现行《建筑结构荷载规范》没有给出这种屋盖结构的风荷载体型系数。一些风致破坏的工程事故表明，开敞式拱形波纹钢盖对风荷载更为敏感，因此明确这种屋盖结构的风压分布规律，对其进行抗风研究具有非常紧迫的现实意义。

本文利用CFD 数值模拟技术对这类屋盖进行了较为系统的参数分析，从中得出其风压分布规律及体型系数，为这种结构进一步的抗风性能研究奠定了基础。 1 研究方法

作者简介：贾永新（1985—），男，山西晋中人，北京交通大学在读硕士, E-mail ：

Jyx198554@

收稿日期：

20010年3月