大攻角及桥面粗糙度对扁平钢箱梁涡振性能的影响.docVIP

大攻角及桥面粗糙度对扁平钢箱梁涡振性能的影响 　　摘要：为探究大攻角及桥面粗糙度对扁平钢箱梁涡振性能的影响，对寸滩长江大桥主梁进行了风洞试验。应用Matlab软件模拟桥面粗糙度变化范围，根据模拟结果选取对应的砂纸在试验中模拟桥面粗糙度，分析了攻角及桥面粗糙度对扁平钢箱梁涡振区间及幅值的影响。试验研究表明：在大攻角下扁平钢箱梁的涡振振幅和范围明显增大，对桥址位于山区等容易发生大风攻角的地区的桥梁应进行大攻角试验。扁平钢箱梁的涡振响应随着桥面粗糙度增大而减小。正攻角范围内，桥面粗糙度对涡振响应的影响随着攻角减小而增大。桥面粗糙度发生变化时，扭转涡振响应更加敏感，变化幅度大于竖向涡振响应变化幅度。 　　关键词：涡振性能；节段模型试验；大攻角；桥面粗糙度 　　中图分类号：U441.2 文献标志码：A 文章编号：1674-4764（2015）06-0032-07 　　Abstract：To study effects of deck roughness and large attack angle on vortex-induced vibration， wind tunnel test has been performed. First， deck roughness was obtained in numeric simulation and according to which， the best match sandpapers were selected for the experiment. Tests of bridge section model were performed with different kinds of attack angles and bridge deck roughness. The results show that the vertical and torsional vortex-induced vibration of flat steel box girder with a large aspect ratio increase at the large attack angle. When the bridge locates in the mountains， it is necessary to do bridge section model test at large attack angle. Deck roughness can reduce the vertical and torsional vortex-induced vibration.Deck roughness has influence on vortex-induced vibration which increases correspondingly with the decrease of the attack angle. Response of torsional vortex-induced vibration is more sensitive to deck roughness， and its range is greater than that of vertical vortex-induced vibration. The accuracy of deck roughness affects the reliability of wind tunnel test. 　　Key words：vortex-induced vibration； bridge section model； large attack angle； deck roughness 　　桥梁涡振通常发生在低风速区间内，长时间涡振会导致结构疲劳并且影响行车的安全性和舒适性。Rio-Niteroi桥在使用阶段曾经高频率地出现一阶大幅涡振[1]，Second Severn桥、东京湾道桥、Great Belt East 桥也曾出现过大幅度的涡振[2-4]。大振幅涡振响应出现频率较高的桥梁需经常关闭，影响正常使用功能并会造成负面社会影响。 　　管青海等[5]对倒梯形整体钢箱梁有无栏杆时的涡振性能进行了研究，通过测量箱梁断面表面压力解释了栏杆影响桥梁断面涡振性能的原因。秦浩等[6]对分离式双幅桥面钢箱梁进行了全桥模型风洞试验，分析了双幅主梁产生两个涡振区间的机理。刘高等[7]通过比例为1/50的节段模型风洞试验分析了分体式钝体双箱钢箱梁两侧有无固定水平气动翼板情况下主梁涡振的变化情况。王骑等[8]研究了分体式钢箱梁梁底导流板和桥面抑振板对涡振的抑制效果，并用大比例节段模型进行了验证。李春光等[9]对带悬挑