Active modal control of timoshenko pipes conveying fluid

Abstract

This paper deals with vibration control of Timoshenko pipes conveying fluid. Excessive vibration in this flow induced vibration problem is suppressed via an active feedback control scheme. The strategy of the active vibration suppression technique will be presented and system dynamics formulated. Optimal independent modal space control technique is applied for best obtainable system performance. The computation consideration, implementation of control strategy, and the effectiveness of the control scheme are addressed. A finite element method is used for both the vibration and control analyses of the problem considered. Classical analysis by solving the partial differential equation is only applicable to systems with simple boundary conditions, such as simply supported pipes. When a more complex situation occurs, a closed form expression becomes very difficult, if not impossible, to obtain. The use of a finite element approach alleviates such deficiencies and is readily applicable to pipes with intermediate supports, nonuniform cross sections, and flexible supports. The problem of a large model size for the control system due to the use of the finite element approach is avoided by using the control technique presented. It is demonstrated in this work that a critical damping design can be achieved for the targeted mode controlled disregarding how large the model size is.