大型不规则雕像结构的抗风及疲劳研究

发布时间：2019-01-13 20:27

【摘要】：雕像建筑与一般高层建筑物不同,其外形极其不规则,结构布置也异常不规则,它的受力情况极其复杂。本文以澳门凼仔岛高约55米的澳门英雄像为研究背景,研究此类大型不规则雕像结构的抗风及风致疲劳问题,找出其薄弱环节,作局部加强。通过分析研究,得到如下主要结论：1、通过对此类结构的空间有限元模型进行模态分析,得出扭转效应对结构的影响不明显,结构的抗扭能力较好。由前几阶振型可以看出结构的薄弱部位。2、由于大型不规则雕像结构的外形极为不规则,本文采用SOLIDWORKS建立建筑物外轮廓的精细化模型,计算结果比以前由杆件粗略的建立外轮廓模型精确很多,然后采用FLUENT软件进行数值风洞模拟分析,通过对像体整体风压系数分布的分析,得到雕像结构的体型系数,具体问题具体分析。本论文的背景工程的体型系数在采用矩形体型系数的基础上增加10%以确保安全。3、针对大型不规则雕像结构,采用线性滤波器法,考虑脉动风的竖向相关性,忽略结构与风之间的相互作用,选取Kaimal脉动风速谱,对结构进行风振响应分析。得出对结构位移起控制作用的是结构的第一振型,采用风振时程分析得到的位移要比荷载规范计算的位移大很多。其中,水平侧移与高度比值比较大的为结构的薄弱位置,一般情况下长悬臂大跨度的杆件为结构的薄弱杆件。对于不满足《高耸结构设计规范》中的水平侧移与高度比的限值要求,可以对薄弱位置做一些处理,改变材质,用轻质高强取代现有的材质,或者在薄弱构件上开洞都可以减少其位移。4、对于大型不规则雕像结构,经过横风向风振分析,如果结构共振区的起点高度大于结构顶点的标高,结构不会发生横风向上的共振,此时结构的风振响应主要以顺风向为主,通常可以忽略结构横风向上的风振响应。5、通过对大型不规则雕像结构的模态分析以及风振响应分析得出结构的薄弱位置,对其中的薄弱杆件采用MSC有限元疲劳分析软件进行风致疲劳分析,评估其疲劳寿命。得出在长期的风载反复作用下,这类结构比较容易发生疲劳破坏,必须在局部采取补强措施来提高其抗疲劳的能力。6、通过改变应力幅值、平均应力及结构的材质等参数进行疲劳分析,对疲劳损伤影响最大的是应力幅值,平均应力和材质对疲劳损伤有一定的影响,在疲劳分析时适当考虑。
[Abstract]:Unlike the general high-rise buildings, the sculptures are extremely irregular in shape and irregular in structure arrangement. In this paper, the wind-resistant and wind-induced fatigue problems of this kind of large irregular statue structures are studied with the background of the Macau hero statue of Taipa Island, which is about 55 meters high, and the weak links are found out, and the local strengthening is made. The main conclusions are as follows: 1. Through modal analysis of the spatial finite element model of this kind of structure, it is concluded that the torsional effect is not obvious, and the torsional resistance of the structure is better. The weak part of the structure can be seen from the first few vibration modes. 2. Because the shape of the large irregular statue structure is very irregular, this paper uses SOLIDWORKS to establish the fine model of the outer contour of the building. The calculated results are much more accurate than the previous rough building of the outer contour model by the bar. Then the numerical wind tunnel simulation analysis is carried out by using FLUENT software, and the figure coefficient of the statue structure is obtained by analyzing the distribution of the overall wind pressure coefficient of the image body. Concrete analysis of specific problems. In this paper, the shape coefficient of the background engineering is increased by 10% on the basis of the rectangular shape coefficient to ensure safety. 3. For the large irregular statue structure, the linear filter method is used to consider the vertical correlation of the pulsating wind. Ignoring the interaction between the structure and the wind, the wind vibration response of the structure is analyzed by selecting the Kaimal spectrum of fluctuating wind speed. It is concluded that the first vibration mode of the structure plays a controlling role in the displacement of the structure, and the displacement obtained by the time-history analysis of wind-induced vibration is much larger than the displacement calculated by the load code. The weak position of the structure is the ratio of horizontal lateral shift to height, and the long cantilever and long span member is the weak member of the structure. In order not to meet the limit requirement of horizontal lateral shift to height ratio in the Design Code for tall structures, we can deal with the weak position, change the material, and replace the existing material with light weight and high strength. Or opening holes in weak members can reduce their displacements. 4. For large irregular statue structures, after crosswind wind vibration analysis, if the starting point of the resonance region of the structure is greater than the elevation of the vertex of the structure, In this case, the wind-induced vibration response of the structure is mainly in the downwind direction, and the wind-induced vibration response on the crosswind direction of the structure can usually be ignored. Through modal analysis and wind-induced vibration response analysis of large irregular statue structure, the weak position of the structure is obtained, and the fatigue life of the weak member is evaluated by MSC finite element fatigue analysis software. It is concluded that under the repeated action of wind load for a long time, this kind of structure is more prone to fatigue failure, and must be strengthened locally to improve its ability to resist fatigue. 6. By changing the stress amplitude, The average stress and the material quality of the structure are analyzed by fatigue analysis. The stress amplitude is the most important factor to the fatigue damage, and the average stress and the material have some influence on the fatigue damage, which should be taken into account in the fatigue analysis.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU311.3

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