Abstract:
Finite element (FE) model of a square cantilevered plate instrumented with
a piezoelectric sensor and an actuator is created using Hamilton’s principle.
Rotational degrees of freedom (dofs) of the FE model are eliminated using
system equivalent reduction expansion process (SEREP). Experimental
mode shapes and natural frequencies are extracted from the structure
using high speed cameras and digital image correlation (DIC) technique.
Initial FE model is updated using experimental mode shapes and natural
frequencies by well-known Berman and Nagy approach. Updated FE model
thus derived is further reduced to first three modes using orthonormal
modal reduction technique. Modal model of the smart plate is then used
to derive state space model of the smart plate. Two Kalman observers are
constructed: one using initial FE model and other using updated FE model.
Active vibration control experiments are conducted on the cantilevered
using these two Kalman observers in the control law. It is observed that
much better vibration suppression occurs when Kalman observer based on
updated FE model is used in the control law. Strategy suggested in this
work to implement a typical active vibration control scheme on a structure
is simple and yet very effective.
