开洞低矮建筑风压特性的数值模拟研究

发布时间：2018-01-05 23:34

本文关键词：开洞低矮建筑风压特性的数值模拟研究　出处：《辽宁工程技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：历年风灾调查表明,低矮建筑的风灾破坏约占总风灾破坏的一半以上,而低矮建筑的整体损坏主要由局部破坏造成,这种局部破坏很大部分是由建筑物的开洞引起的。通常低矮建筑会因使用功能需要,或在强风中因风致飞掷物的撞击导致门窗破坏而形成开洞,开洞后低矮建筑的洞口处的内部风压会骤然增大,此时抗风设计的结构风压不仅要考虑外压作用,还要考虑内外压的共同作用。目前国内外对开孔低矮建筑的风压特性研究尚处于探索阶段,工程师们在结构设计时通常忽略或粗略估计风致内压作用,目前各国规范对于开洞建筑的风压取值也未作出明确规定,这样会造成建筑结构安全的巨大隐患。为此,本文对开孔低矮建筑的风压特性进行了系统研究,以期为开孔低矮建筑抗风设计提供有益的参考。本文基于流体动力学(CFD)原理,首先采用数值模拟方法模拟了国际通用低矮建筑标准模型TTU的风压特性,通过数值模拟结果和已有TTU试验结果的对比分析,验证了数值模拟方法研究开洞低矮房屋风压特性的准确性和可靠性。其次本文对多个主开洞的低矮建筑的风压特性进行了研究。目前开孔低矮建筑风致内压的研究成果中,对于单个主开洞的风压特性研究较多,但多个主开洞的情况在低矮建筑中也是很常见的,而相关研究却是极为有限。本文研究了低矮建筑单面多个主开洞和多面多个主开洞时,在不同风速和风向角下低矮建筑的风压变化规律,并与单面开单洞的风压变化规律进行了对比,发现了多个主开洞低矮建筑的风压特性规律。提出了“通口效应”,即低矮建筑在多面开多个主洞口时,当迎风面开洞位置、背风面开洞位置和风向在一条直线上时,迎风面和背风面的风压系数达到最小值(除90°风向角)。研究结果为多个主开洞低矮房屋的抗风设计提供了依据。最后研究了新型低矮建筑——索穹顶结构存在开洞时的风压特性,目前对于开洞索穹顶风致内压特性的研究尚处于空白状态。本文研究了不同开洞位置、不同风向角、不同风速时,索穹顶结构的风压分布规律。较详细的分析了开洞穹顶结构的平均风压系数变化规律,为开洞索穹顶结构的抗风设计提供了有价值的参考。本文研究得到的主要结论包括：(1)“通口效应”的存在：低矮建筑在两面或多面开多个主洞口时,当迎风面开洞位置、背风面开洞位置和风向在一条直线上时迎风面、背风面的风压系数达到一个最小值(除90°风向角)。(2)低矮建筑在多面开洞时,当迎风面开孔数量越多背风面开孔数量越少,无论是迎风面还是背风面建筑物洞口处的平均风压系数都有增大的趋势,这是因为此种条件下建筑对风的阻碍作用增大所致。(3)低矮房屋在三面开孔时,0°-60°风向角下建筑物迎风面、背风面和侧面的平均风压系数都为正值,这与建筑单面、双面开孔时的情况有所不同。(4)索穹顶结构在单个主开洞口时和低矮建筑一样,在其它条件不变时,洞口处的平均风压系数随着风速的增加而逐渐增大,但有所区别的是索穹顶结构迎风面的平均风压系数多数在大于1的范围之内。索穹顶结构在单面开洞时,随着开洞高度的变化结构顶部的平均风压系数的正负变化明显。(5)由于索穹顶结构几何形态的渐变性,当开洞位置和风向角变化时,结构表面存在平均风压系数为零的点、或线。(6)索穹顶结构开洞时的风压特性与未开洞相比会发生较大改变,在结构设计时应引起足够重视。
[Abstract]:The investigation reveals that the typhoon, low building wind damage to more than half of total damage, and overall damage to low rise building is mainly caused by local damage, the local damage is mostly caused by the building openings. Usually low buildings because of the use function, or in the wind by throwing the impact of wind fly doors lead to damage the formation of holes, the holes of internal pressure low rise building openings will suddenly increase, the wind structure of wind resistant design should not only consider the effect of external pressure, but also consider the joint action of internal and external pressure. At home and abroad to study the characteristics of wind pressure hole of low rise building is still at the exploratory stage, engineers often ignore or a rough estimate of wind-induced internal pressure acting on the structure design, the current national standard for wind pressure opening building is not made it clear that this will cause the building. The great hidden danger of safety. Therefore, this paper made a systematic study on the characteristics of wind pressure hole of low rise building, in order to provide a useful reference for the opening of low rise building wind resistant design. In this paper, based on fluid dynamics (CFD) principle, firstly, using the method of numerical simulation of wind pressure characteristics for low rise building international standard model TTU to simulate the. Through comparative analysis of numerical simulation results and existing TTU test results, verify the accuracy and reliability of the numerical simulation method to study the opening of wind pressure characteristics. Secondly, low building for a plurality of openings of the main wind pressure characteristics were studied. The current research results of wind-induced internal pressure in hole of low rise buildings, for more research on wind pressure the main characteristics of a single hole, but a number of openings is very common in the low rise building, and related research is extremely limited. This paper studied the low building On one side of a plurality of main openings and a plurality of main surface openings, pressure variation in different wind speed and wind direction of low rise building, and with pressure variation of single hole were compared, discovered the law of wind pressure characteristics of a plurality of main openings. Low rise buildings put forward "hole effect", which is low the building in the multi-faceted open multiple main entrance, when the position of windward leeward openings, opening location and direction in a straight line, the windward and leeward wind pressure coefficient reaches the minimum value (in addition to the 90 degree of wind direction). The research results provide a basis for wind resistant design of a plurality of main openings low houses. At the end of the new low rise buildings - cable dome structure has the characteristics of wind pressure openings, the opening of cable dome wind-induced internal pressure study is still in the blank. This paper studies the different opening position, different wind direction, wind speed is not the same The wind pressure distribution, the cable dome structure. A more detailed analysis of the average wind pressure coefficient changes with the dome structure, which provides valuable reference for the opening of cable dome structure wind resistant design. The main conclusions of this study include: (1) the "hole effect" in: low rise buildings open the main entrance on both sides or more, when the position of windward leeward openings, opening location and direction in a straight line on the windward and leeward side of the wind pressure coefficient reaches a minimum value (except the wind angle of 90 ~). (2) low rise buildings in multiple openings, when the windward opening number the leeward side opening number less, both the average wind pressure coefficient of windward or leeward building openings have a tendency to increase, this is because the conditions of building block wind increased. (3) low rise buildings on three sides opening, 0 ~ -60 Degree of wind direction of buildings under the windward side, the average wind pressure coefficient and side surfaces of the leeward is positive, and the double hole single building, the situation is somewhat different. (4) the cable dome structure in a single primary open hole and low rise buildings, in other conditions remain unchanged, the average wind pressure coefficient at the entrance gradually increases with the increase of wind speed, but the difference is that the cable dome structure the windward surface of the average wind pressure coefficient is greater than 1 in most of the scope of the cable dome structure in single hole, with positive and negative average wind pressure coefficient variation of the height of the opening at the top of the structure change obviously. (5) because of the gradual change of cable dome the structure, when the opening location and direction angle, the average wind pressure coefficient is zero point or line structure of the surface. (6) cable dome structure with the characteristics of wind pressure when compared with no openings will change greatly in structure. Time should be given enough attention.

【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU312.1

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