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折疊網殼結構風致雪漂效應的數(shù)值模擬研究

發(fā)布時間:2019-06-29 10:04
【摘要】:野營折疊網殼帳篷被廣泛應用于民用和軍事領域,此類房屋通過編織材料組成其防護層和構造層,致使房屋自重在整個荷載中所占比重很小,屬于典型的輕型房屋,故風和雪荷載是其結構設計的主要控制荷載。針對風荷載目前已有相對深入的研究,而對于雪荷載,風致雪漂效應會造成積雪在折疊網殼屋蓋表面產生不均勻分布,其結果常會導致結構局部或整體坍塌,且現(xiàn)行《建筑結構荷載規(guī)范》(GB50009-2012)僅根據(jù)以往的設計經驗和國際標準以及國外有關資料概括性地規(guī)定了典型規(guī)則屋面積雪分布系數(shù),并不能適用于目前大量涌現(xiàn)的外形獨特且對雪荷載敏感的輕質屋蓋結構,故亟需對折疊網殼結構的風雪效應進行深入研究與探討。在風致雪漂移的研究方法中,現(xiàn)場實測可以獲得最準確的數(shù)據(jù),但是所需周期長,較大程度上受制于自然條件等因素;試驗研究受到試驗條件和相似準則的限制致使耗費成本過高。隨著計算機技術的高速發(fā)展,CFD(Computational Fluid Dynamics)數(shù)值模擬技術以其周期短、成本低、易滿足相似性和高重復性模擬的優(yōu)點被廣泛且深入地應用于風雪運動的研究。為了深入研究風致折疊網殼結構表面積雪分布規(guī)律,本文基于歐拉-歐拉方法和空氣相與雪相均連續(xù)且單向耦合的基本假定,考慮風雪漂移的躍移運動模式和懸移運動模式,運用大型通用計算流體動力學軟件ANSYS Fluent中的Mixture多相流模型理論,采用自編C語言UDF解釋型程序與Fluent作接口實現(xiàn)邊界條件的嵌入,并計及壁面上積雪侵蝕與沉積,建立風致雪漂的數(shù)值計算模型。首先模擬三維算例立方體模型周圍的積雪分布,探討與分析數(shù)值風洞的關鍵技術與參數(shù),在與實測結果對比后驗證所建立數(shù)值模型的可行性與有效性,分析表明三方程klk--ω湍流模型具有較優(yōu)模擬結果。在此基礎上,以風速、風向角和地貌類型為分析參數(shù),模擬折疊網殼結構的風致雪漂效應,求解風雪流流場后分析風雪耦合場規(guī)律,并獲得結構表面風致雪漂的積雪分布系數(shù),為近似該體型結構的抗風雪設計提供參考依據(jù)。結果表明:風雪流繞流具有復雜體型的折疊網殼結構異常紊亂,較低風速的持續(xù)作用下對其表面積雪分布尤為不利,結構表面積雪的侵蝕與沉積受風向角影響會發(fā)生在不同區(qū)域,總體呈現(xiàn)以侵蝕為主、背風面局部沉積的規(guī)律,因風向角的變化引起同一分區(qū)雪荷載的改變對此類雪荷載敏感性結構的抗風雪設計至關重要,此外,結構表面積雪沉積系數(shù)與四類地貌的開闊程度呈現(xiàn)負相關性。
[Abstract]:Camping folding reticulated shell tent is widely used in civil and military fields. This kind of house is composed of protective layer and structural layer through braided materials, which makes the proportion of building weight in the whole load very small, so it belongs to typical light building, so wind and snow load is the main control load of its structural design. At present, the wind load has been studied relatively deeply, but for the snow load, the snow drift effect caused by the wind will cause the uneven distribution of snow on the surface of the folded reticulated shell roof, and the results often lead to the local or overall collapse of the structure, and the current Code of Building structure load (GB50009-2012) only specifies the snow distribution coefficient of the typical regular roof according to the previous design experience and international standards, as well as the relevant foreign data. It is not suitable for a large number of lightweight roof structures with unique shape and sensitive to snow load, so it is urgent to study and discuss the snowstorm effect of folded reticulated shell structure. In the research method of wind-induced snow drift, the most accurate data can be obtained from the field measurement, but the required period is long, which is restricted to a large extent by natural conditions, and the experimental research is limited by the test conditions and similar criteria, resulting in too high cost. With the rapid development of computer technology, CFD (Computational Fluid Dynamics) numerical simulation technology has been widely and deeply used in the study of snow movement because of its short cycle, low cost, easy to meet the advantages of similarity and high repeatability simulation. In order to deeply study the snow distribution law on the surface of wind-induced folded reticulated shell structure, based on the Euler-Euler method and the basic assumption that the air phase and snow phase are continuous and unidirectional coupling, considering the jump motion mode and suspension motion mode of snow drift, the Mixture multiphase flow model theory in large-scale general computational fluid dynamics software ANSYS Fluent is used, and the interface between self-compiled C language UDF explanatory program and Fluent is used to realize the embedding of boundary conditions. Taking into account the erosion and deposition of snow on the wall, the numerical model of wind-induced snow drift is established. Firstly, the snow distribution around the cube model of a three-dimensional example is simulated, and the key techniques and parameters of the numerical wind tunnel are discussed and analyzed. The feasibility and effectiveness of the numerical model are verified by comparing with the measured results. The analysis shows that the three-equation klk-- 蠅 turbulence model has better simulation results. On this basis, taking wind speed, wind direction angle and geomorphological type as analysis parameters, the wind-induced snow drift effect of folded reticulated shell structure is simulated, the law of wind-snow coupling field is analyzed after solving the wind-snow flow field, and the snow distribution coefficient of wind-induced snow drift on the surface of the structure is obtained, which provides a reference for the anti-snow design of the similar structure. The results show that the folding reticulated shell structure with complex shape is abnormally disordered, and the snow distribution on the surface is particularly disadvantageous under the continuous action of low wind speed. The erosion and deposition of snow on the surface of the structure will occur in different areas under the influence of wind direction angle, which is dominated by erosion and local deposition on the leeward surface. The change of snow load in the same zone caused by the change of wind direction angle is very important to the anti-snow design of this kind of snow load sensitive structure. In addition, the snow deposition coefficient on the surface of the structure is negatively correlated with the openness of the four geomorphology.
【學位授予單位】:長安大學
【學位級別】:碩士
【學位授予年份】:2017
【分類號】:TU399;TU312.1

【參考文獻】

相關期刊論文 前10條

1 顏衛(wèi)亨;黃政;吳東紅;張茂功;;折疊網殼結構風壓分布特性的神經網絡預測研究[J];應用力學學報;2015年05期

2 莫華美;范峰;洪漢平;;積雪漂移風洞試驗與數(shù)值模擬研究中輸入風速的估算[J];建筑結構學報;2015年07期

3 周fE毅;劉長卿;顧明;譚敏海;;拉格朗日方法在風雪運動模擬中的應用[J];工程力學;2015年01期

4 李躍;袁行飛;;大跨度球殼屋蓋風致積雪數(shù)值模擬及雪荷載不均勻分布系數(shù)研究[J];建筑結構學報;2014年10期

5 孫曉穎;洪財濱;武岳;范峰;;建筑物周邊風致雪漂移的數(shù)值模擬研究[J];工程力學;2014年04期

6 顏衛(wèi)亨;王劍;吳東紅;張茂功;;局部開洞的折疊網殼結構表面風壓分布研究[J];工程力學;2013年10期

7 王衛(wèi)華;廖海黎;李明水;;基于時變邊界屋面積雪分布數(shù)值模擬[J];西南交通大學學報;2013年05期

8 周fE毅;劉長卿;顧明;;躍移雪顆粒運動特性的數(shù)值模擬研究[J];同濟大學學報(自然科學版);2013年04期

9 周fE毅;李雪峰;顧明;張艷萍;;風吹雪數(shù)值模擬的兩方程模型方法[J];空氣動力學學報;2012年05期

10 顏衛(wèi)亨;邰家醉;張茂功;;野營折疊網殼結構表面定常風場的數(shù)值模擬研究[J];工程力學;2012年04期

相關會議論文 前2條

1 李雪峰;周fE毅;顧明;;北京南站屋面雪壓分布規(guī)律分析[A];第十三屆全國結構風工程學術會議論文集(下冊)[C];2007年

2 李雪峰;周fE毅;顧明;;改進RSM湍流模型模擬雪飄移[A];第十四屆全國結構風工程學術會議論文集(下冊)[C];2009年

相關博士學位論文 前1條

1 孫芳錦;膜結構風振流固耦合效應和風致雪壓的理論分析及數(shù)值模擬研究[D];遼寧工程技術大學;2009年

相關碩士學位論文 前4條

1 李躍;大跨空間結構屋面雪荷載研究[D];浙江大學;2014年

2 洪財濱;典型形式大跨度屋蓋風致雪漂移的數(shù)值模擬研究[D];哈爾濱工業(yè)大學;2012年

3 莫華美;典型屋面積雪分布的數(shù)值模擬與實測研究[D];哈爾濱工業(yè)大學;2011年

4 蔣坤;屋面積雪分布系數(shù)的研究分析[D];沈陽建筑大學;2011年

,

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