轴向流中不同约束条件柔性板稳定性分析  

Stability of flexible plates with different boundary conditions in axial flow

作　　者：刘梅清[1] 赵文胜[1] 蒋劲[1] 林琦[1] 

机构地区：[1]武汉大学动力与机械学院,湖北武汉430072

出　　处：《排灌机械工程学报》2011年第1期39-44,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(50879062);教育部博士点基金资助项目(20090141110057)

摘　　要：基于板的轴向不可延伸假设,推导了轴向流中柔性板在不同约束条件下的运动偏微分方程及边界条件,柔性板采用两端固支、两端简支和悬臂3种支撑形式.采用伽辽金法离散该运动偏微分方程,采用复模态分析法,通过对物理量作量纲为一的处理,分析了3种约束条件下柔性板的失稳特性,计算了失稳临界速度,分析了振动频率、阻尼随流体速度的变化关系.研究结果表明,柔性板在较低流速作用下,保持稳定状态,在足够大流速作用下,发生屈曲失稳和颤振.两端固支柔性板发生一阶屈曲失稳和二阶、三阶振型颤振;两端简支柔性板发生一阶、二阶屈曲失稳和二阶、三阶振型颤振;悬臂柔性板由于受到流体阻尼作用,不会发生一阶屈曲失稳,发生二阶、三阶振型颤振.The partial differential equations of motion based on the inextensibility assumption were derived for flexible plates with different boundary conditions subjected to axial flow. The flexible plates were either clamped or pinned at both ends, or clamped at the leading edge and free at the trailing edge （ cantilevered）. The Galerkin method was used to discretize the partial differential equations. The complex modal analysis was adopted to analyze the instability characteristics of the plates. The non-dimensional critical flow velocities were predicted, the relationship between damping, frequency and flow velocity were also discussed. It is shown that for suffieiently high flow velocities the plates may be subject to buckling and flutter. Typically, clamped-clamped and pinned-pinned plates are subject to buckling in their first mode, and to flutter in their higher modes. Furthermore, second mode buckling occurs for pinned-pinned plates, while cantilevered plates flutter in their second and third modes.

关 键 词：柔性板 流固耦合 颤振 复模态分析 伽辽金法 

分 类 号：S277.9[农业科学—农业水土工程] O323[农业科学—农业工程]