本征正交分解下的桥梁软颤振表面风压场分析
|
摘要
从弹性悬挂的刚体测振和测压模型入手,采用本征正交分解(proper orthogonal decomposition,POD)方法对钝体断面软颤振时表面风压数据进行分析。结果显示,POD第一阶模态是产生颤振的主要因素,该阶能量所占比例高达60%以上,功率谱密度曲线在颤振频率处有明显的窄带现象,且该阶模态下的三分力时程与风洞实测三分力时程最吻合;POD各阶模态形状与断面各阶模态下表面压力波动分布相似,即POD模态形状起伏处压力波动较大,平坦处压力波动较小。
In this paper,the POD( proper orthogonal decomposition) method is used to analyze the surface wind pressure data of the soft flutter of the blunt body when the rigid body vibration and pressure measurement model is used. The results show that the first mode of POD is the main factor of flutter. The specific gravity of the order is as high as 60%,and the power spectral density curve has obvious narrow band phenomenon at the flutter frequency. Also the time history of the mode's tri-component force develops in accordance with that of the wind tunnel. The mode shapes of POD have similar changes to the surface pressure fluctuations in various modes. The pressure in the ups and downs of the POD mode shows large fluctuation while the pressure at the flat surface has small fluctuation.
In this paper,the POD( proper orthogonal decomposition) method is used to analyze the surface wind pressure data of the soft flutter of the blunt body when the rigid body vibration and pressure measurement model is used. The results show that the first mode of POD is the main factor of flutter. The specific gravity of the order is as high as 60%,and the power spectral density curve has obvious narrow band phenomenon at the flutter frequency. Also the time history of the mode's tri-component force develops in accordance with that of the wind tunnel. The mode shapes of POD have similar changes to the surface pressure fluctuations in various modes. The pressure in the ups and downs of the POD mode shows large fluctuation while the pressure at the flat surface has small fluctuation.
引文
[1]ARMITT J.Eigenvector analysis of pressure fluctuations on the West Burton instrumented cooling tower[R].U.K.:Central Electricity Research Laboratories,1968:68-114.
[2]HOLMES J.Analysis and synthesis of pressure fluctuations on bluff bodies usingeigenvectors[J].Journal of Wind Engineering and Industrial Aerodynamics,1990,33(1/2):219-230.
[3]BIENKIEWICZ B,TAMURA Y,HAM H,et al.Proper orthogonal decomposition and reconstruction of multi-channel roof pressure[J].Journal of Wind Engineering and Industrial Aerodynamics,1995,54(2):369-381.
[4]HOLMES J D,SANKARAN R,KWOK K C S,et al.Eigenvector modes of fluctuating pressures on low-rise building models[J].Journal of Wind Engineering and Industrial Aerodynamics,1997,69(97):697-707.
[5]BAKER C J.Aspects of the use of proper orthogonal decomposition of surface pressure fields[J].Wind&Structures An International Journal,2000,3(2):97-115.
[6]GRENET E T D,RICCIARDELLI F.Analysis of the wind loading of square cylinders using covariance proper transformation[J].Wind&Structures An International Journal,2004,7(2):71-88.
[7]RICCIARDELLI F,GRENET E T D,SOLARI G.Analysis of the wind loading of a bridge deck box section using proper orthogonal decomposition[J].International Journal of Fluid Mechanics Research,2002,29(3/4):60-71.
[8]李方慧,倪振华,沈世钊,等.POD原理解析及在结构风工程中的几点应用[J].振动与冲击,2009,28(4):29-32.
[9]王思涛.典型桥梁主梁断面气动特性风洞试验研究[D].大连:大连理工大学,2015:10-15.
[10]中华人民共和国交通部.公路桥梁抗风设计规范:JTG/T D60-01—2004[S].北京:中国标准出版社,2004:104-106.
[11]赵林,殷峰,葛耀君.桥梁断面表面压力分布与颤振驱动机理试验研究[C]//中国土木工程学会桥梁与结构工程分会风工程委员会.上海:第十一届全国结构风工程学术会议论文集,2003:274-280.
[2]HOLMES J.Analysis and synthesis of pressure fluctuations on bluff bodies usingeigenvectors[J].Journal of Wind Engineering and Industrial Aerodynamics,1990,33(1/2):219-230.
[3]BIENKIEWICZ B,TAMURA Y,HAM H,et al.Proper orthogonal decomposition and reconstruction of multi-channel roof pressure[J].Journal of Wind Engineering and Industrial Aerodynamics,1995,54(2):369-381.
[4]HOLMES J D,SANKARAN R,KWOK K C S,et al.Eigenvector modes of fluctuating pressures on low-rise building models[J].Journal of Wind Engineering and Industrial Aerodynamics,1997,69(97):697-707.
[5]BAKER C J.Aspects of the use of proper orthogonal decomposition of surface pressure fields[J].Wind&Structures An International Journal,2000,3(2):97-115.
[6]GRENET E T D,RICCIARDELLI F.Analysis of the wind loading of square cylinders using covariance proper transformation[J].Wind&Structures An International Journal,2004,7(2):71-88.
[7]RICCIARDELLI F,GRENET E T D,SOLARI G.Analysis of the wind loading of a bridge deck box section using proper orthogonal decomposition[J].International Journal of Fluid Mechanics Research,2002,29(3/4):60-71.
[8]李方慧,倪振华,沈世钊,等.POD原理解析及在结构风工程中的几点应用[J].振动与冲击,2009,28(4):29-32.
[9]王思涛.典型桥梁主梁断面气动特性风洞试验研究[D].大连:大连理工大学,2015:10-15.
[10]中华人民共和国交通部.公路桥梁抗风设计规范:JTG/T D60-01—2004[S].北京:中国标准出版社,2004:104-106.
[11]赵林,殷峰,葛耀君.桥梁断面表面压力分布与颤振驱动机理试验研究[C]//中国土木工程学会桥梁与结构工程分会风工程委员会.上海:第十一届全国结构风工程学术会议论文集,2003:274-280.