Enhancement of the stability of beams with piezoelectric transducers

Abstract

Subject of the present work is the stability control of beam-type structures under a compressive force. Main scope of this article is to increase the critical buckling load by means of active feedback control. The compressive force is applied with the help of a cable which is fixed at the tip of the free end and passes through a point at the fixation of the beam. The structural displacement of the column is controlled by a constant gain feedback algorithm, with strain sensors used as input and piezoelectric actuators. A consistent theoretical formulation of this nonconservative system based on the Bernoulli–Euler beam theory is presented. The formulation takes into account the complete mechatronic system, including the influence of the controller with discrete strain measurements as well as distributed piezoelectric patches. The analytical results are compared to numerical simulations. The influence of the controller on the buckling load, the appearance of flutter instability and the limits of the controller’s operation range are highlighted.