Improved active control of a functionally graded material beam with piezoelectric patches

Abstract

In this paper, the active vibration control tools are implemented for the vibration control of functionally graded material (FGM) beam with piezoelectric actuators and sensors. The properties of FGM are functionally graded in the thickness direction according to the volume fraction power law distribution. An analytical formulation, based on an efficient trigonometric shear deformation theory, is used to obtain a state space equation. The main steps to set up active control of FGM vibrations are considered in this work. The actuators’ and sensors’ locations are defined from two optimization problems using controllability and observability gramians. The linear quadratic regulator (LQR) control law, including a state observer is computed. Numerical examples show the influence of the volume fraction index on the observability and controllability properties of the system. The LQR leads to efficient active damping for several kinds of excitations. The study of the uncertainty in the volume fraction index shows the robustness of the control method, and also the possible induced defects.