雙層類橢球冠形大跨屋面的表面風壓數值模擬

鄧長根+梅潔晗+陸平

建筑科學與工程學報2014年文章編號：16732049(2014)01013805

收稿日期：20131107

作者簡介：鄧長根（1962），男，江西南城人，教授，博士研究生導師，工學博士

摘要：基于計算流體動力學（CFD）數值模擬方法，對擬建雙層類橢球冠形大跨屋面進行了表面風壓分析，得到了其在不同風向角下的風壓分布情況和速度流場分布趨勢，并進一步給出了擬建建筑在最不利工況下的風壓系數分布等值線。結果表明：雙層類橢球冠形大跨屋面的最大正壓區出現在迎風面的近地處及上下部交界處，而最大負壓區則出現在側面的上下部交界處和頂面；上下部交界處由于形成了凹角，很容易出現最大局部正負壓區塊，因此在結構抗風設計時需要進行局部加強。

關鍵詞：大跨屋面；類橢球冠；數值模擬；風壓系數；風向角

中圖分類號：TU312.1文獻標志碼：A

Numerical Simulation of Wind Pressures on Longspan Roof of

Double Hyperellipsoidal CrownsDENG Changgen1, MEI Jiehan1, LU Ping2

（1. Department of Building Engineering, Tongji University, Shanghai 200092, China;

2. Shanghai Tongji Kaiyuan Architectural Design Co., Ltd., Shanghai 200092, China）Abstract: By the method of computational fluid dynamics (CFD) numerical simulation, the analyses of windinduced surface pressure of the proposed longspan roof of double hyperellipsoidal crowns were conducted. The distributing characteristics of mean wind pressure and velocity flow field in different wind directions were obtained. On that basis, the isolines of wind pressure coefficient distribution of the proposed architecture under the most unfavorable condition were presented. The results show that the maximum positive pressure zone locates on the upwind side near the ground, while the juncture of top and bottom on the upwind side also grows a zone of maximum positive pressure. The maximum negative pressure zone lies on the upwind side close to the top of the roof, while a maximum negative pressure zone appears in the juncture of top and bottom on the side face. Therefore, the juncture of top and bottom forms concave angle, which leads to maximum local positive pressure zones or negative pressure zones, so local reinforcement should be considered in the design of structural windresistance.

Key words: longspan roof; hyperellipsoidal crown; numerical simulation; wind pressure coefficient; wind direction

0引言

作為建筑結構的主要側向荷載，風荷載一直是大跨度空間結構設計的核心問題之一。這主要是由于以下3個原因：①大跨度空間結構的自重較小，柔性偏大，自振頻率低，因此對風荷載十分敏感；②隨著跨度的不斷增加、高度的不斷增大，風荷載對結構的影響不斷增強，已逐步成為結構設計中的控制荷載；③由于大跨度空間結構在體型上的靈活性，使得其體型日趨復雜，各國現行的荷載規范中無法提供與之對應的風荷載體型系數、風壓分布規律和風振系數，造成了設計上的難度。

近年來，關于大跨度曲面結構數值模擬的分析研究逐漸興起。……