不可压缩流中非对称板状结构模态局部化分析的摄动法

Perturbation Method of Analyzing Mode Localization of Asymmetrical Plate-type Structure in Incompressible Flows

本文研究一个两跨板状简单模型在不可压缩流中振动时的固有动特性。应用假设模态法建立系统的运动微分方程。应用摄动法着重考虑了结构的长度非对称及扭转刚度非对称对系统模态局部化程度的影响。结果表明,二阶摄动理论能很好地用于计算该系统的动态特性。水的耦合作用对上、下板模态局部化现象的影响有差异。长度非对称参数是导致结构模态产生局部化现象的主要原因。扭簧刚度扰动也对结构模态局部化现象有较大影响。

The dynamical characteristics of a simple two-span parallel flat plate-type model vibrating in incompressible water are studied here. The assumption mode method is used to form the motion equation of the structure. By using a second order perturbation method, the great emphasis is focused on the influences of the asymmetrical parameter of the structure, the deviation of length and stiffness of the torsional spring on the degrees of mode localization of the structure. The results show that the second method can be applied to predict the dynamical characteristics of the structure accurately. The influences of the coupling effect of the fluid on the phenomena of the two piece beams' mode localization are different. The asymmetrical parameter of length is the main factor that leads to the behaviors of mode localization of the structure. The deviation of stiffness of the torsional spring, too, has significant influences on the phenomena of mode localization.