Extremely large-amplitude oscillation of soft pipes conveying fluid under gravity  

作　　者：Wei CHEN Ziyang HU Huliang DAI Lin WANG 

机构地区：[1]Department of Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China [2]Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment,Wuhan 430074,China

出　　处：《Applied Mathematics and Mechanics(English Edition)》2020年第9期1381-1400,共20页应用数学和力学（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.11672115,11622216,and 11972167)。

摘　　要：In this work,the nonlinear behaviors of soft cantilevered pipes containing internal fluid flow are studied based on a geometrically exact model,with particular focus on the mechanism of large-amplitude oscillations of the pipe under gravity.Four key parameters,including the flow velocity,the mass ratio,the gravity parameter,and the inclination angle between the pipe length and the gravity direction,are considered to affect the static and dynamic behaviors of the soft pipe.The stability analyses show that,provided that the inclination angle is not equal to π,the soft pipe is stable at a low flow velocity and becomes unstable via flutter once the flow velocity is beyond a critical value.As the inclination angle is equal to π,the pipe experiences,in turn,buckling instability,regaining stability,and flutter instability with the increase in the flow velocity.Interestingly,the stability of the pipe can be either enhanced or weakened by varying the gravity parameter,mainly dependent on the value of the inclination angle.In the nonlinear dynamic analysis,it is demonstrated that the post-flutter amplitude of the soft pipe can be extremely large in the form of limit-cycle oscillations.Besides,the oscillating shapes for various inclination angles are provided to display interesting dynamical behaviors of the inclined soft pipe conveying fluid.

关 键 词：large-amplitude oscillation soft pipe conveying fluid gravity effect FLUTTER 

分 类 号：O322[理学—一般力学与力学基础] O326[理学—力学]