【作者】 陈阳；

【导师】 孙瑛；

【作者基本信息】 哈尔滨工业大学 ， 建筑与土木工程（专业学位）， 2021， 硕士

【摘要】 金属屋面系统由于其质量轻、跨度大、外观适应性广等优点,广泛的被应用于各类大跨度建筑的屋盖结构中,但其性能受风荷载影响较大,在恶劣风环境下,金属屋面被风掀开的事故时有发生,据不完全统计,每年由金属屋面发生风揭破坏造成的直接或间接经济损失可达数亿元。随着风揭事故越来越得到人们的关注,加拿大、欧洲、澳大利亚、日本以及美国等飓风频发的国家根据不同地区的风荷载规范、风洞试验结果制定了不同试验方法并编写了相关的试验规范,但是我国目前缺乏基于国内规范及试验结果制定的的试验方法,且各国规范间试验方法差距较大,同一种试件采用不同试验方法可能会得到多种不同的抗风揭等级,因此对各试验方法进行深入研究具有实际意义。为了进一步了解各方法的适用范围及合理性,本文对各试验方法进行了参数化对比,通过数值模拟分析,分别探讨了每个参数对分析结果的影响,重点对加拿大规范中提出的试验方法进行研究,基于已有的大跨屋盖风洞测压试验结果展开动态加载序列统计,最终提出适用于大跨屋盖金属屋面系统抗风揭承载力试验的动态加载序列。主要研究内容如下:(1)对比国内外的抗风揭试验规范,总结试验方法差异,基于数值模拟方法,对比抗风揭试验中试件大小、荷载等级、加压方式、升压、持压时间以及压力起始点几个关键参数对分析结果的影响,最终发现与其他参数相比,加压方式对分析结果的影响最大,相比静态加载,动态加载可使跨中竖向位移与最大应力分别增加80%和15%。(2)参考加拿大规范中动态风荷载序列的生成方式,结合雨流计数法对平屋盖风洞测压试验的风压时程进行统计,依次进行滤波、计数、归类、分级,将其转换为可用于设计抗风揭试验的风荷载序列,并分析了屋面分区、风向角、跨高比、风速、地貌等因素对风荷载序列统计值的影响,最终发现位于迎风前缘位置处的I分区风荷载序列统计值更易受到不同因素的影响,而处于屋面中部的V分区风荷载序列统计值较为稳定,但是Group1的循环次数较多。(3)对比平屋盖与柱壳屋盖风荷载序列统计值的差别,发现二者在不同分区间的分布呈现不同的对称特性,且位于柱壳屋盖中部的V分区循环次数较多,并介绍了加拿大规范中动态抗风揭试验加载序列的设计方法,综合平屋盖屋面I分区风荷载序列统计值在各因素下的最大值和最小值,提出了可以用于检验金属屋面在设计风荷载作用下安全性的A等级加载序列,并以此为基础提出了可以用于确定抗风揭承载力的B、C、D、E等级加载序列。更多还原

【Abstract】 It is widely used for metal roof system in the roof structure of various large-span buildings due to its advantages of light weight,large span,and wide appearance adaptability.However,their performance is greatly affected by wind loads.Under severe wind conditions,accidents of metal roofs being lifted by the wind occur from time to time.According to incomplete statistics,the direct or indirect economic losses caused by wind-uplift damage of metal roofs can reach hundreds of millions of yuan each year.As wind uplift accidents have attracted more and more attention,countries with frequent hurricanes such as Canada,Europe,Australia,Japan,and the United States have formulated different test methods and compiled relevant test methods based on wind load codes and wind tunnel test results in different regions.Test specifications,but there are little test methods based on domestic specifications and test results in China,and there is a large gap in test methods between national specifications.The same test piece may get a variety of different wind resistance levels by using different test methods.Therefore,it is of practical significance to conduct in-depth research on various test methods.In order to understand the applicable scope and rationality of each method further,this paper compares the parameters of each test method.Through numerical simulation analysis,the influence of each parameter on the analysis result is discussed separately,with emphasis on the test method proposed in the Canadian standard.Based on the results of the existing long-span roof wind tunnel pressure test results,the dynamic loading sequence statistics are developed,and finally a dynamic loading sequence suitable for the wind resistance test of the large-span metal roof system is proposed.The main research contents are as follows:(1)Based on numerical simulation methods,this paper compares the size of the specimens,load levels,compression methods,pressure rise time,holding time,and pressure starting points in the wind-lifting tests by comparing with domestic and foreign standards for wind-lifting tests and summarizing the differences in test methods,finally reaches the conclusion that the biggest influence of parameters on the analysis results is the compression method.Compared with static loading,dynamic loading can increase the vertical displacement in mid-span and maximum stress by 80% and 15%,respectively.(2)With reference to the method of dynamic wind load sequence generated in Canadian code,the wind pressure time history of flat roof wind tunnel pressure test is calculated,filtered,counted,sorted,classified and finally converted into a practical dynamic loading sequence in wind uplift test combined with rain flow counting method.This paper compares the influence of roof partition,wind direction angle,span-to-height ratio,wind speed,landform and other factors on the statistical value of wind load sequence,and finally reaches the conclusion that the statistical value of the loading sequence of I partition located at the front edge of the wind is more susceptible to the influence of different factors,but that in the V district in the middle of the roof is relatively stable,and has more cycle numbers in Group1 in contrast.(3)Comparing the statistical value of the loading sequence between flat roofs and cylindrical roofs,it is found that the distribution of each roof presents different symmetry characteristics,and the V zone in the middle of the cylindrical roof has more cycle numbers,and the method to design dynamic wind uplift test in Canadian standard is also introduced.By integrating the maximum and minimum of the statistical value of the wind load sequence of the partition I of different conditions,an A-level dynamic loading sequence is proposed,which can be used to test the safety of the metal roof under the design wind load.Based on that,the B,C,D,E-level loading sequence that can be used to determine the wind resistance capacity is proposed.更多还原