This paper presents simulation and experimental results on the stability and control performance of decentral-
ized velocity feedback loops on a rectangular aluminium panel. Each feedback loop is made of a composite
piezoelectric patch actuator with an accelerometer sensor at its centre. The actuator is fabricated with six
triangular anisotropic piezoelectric patches assembled into an hexagonal patch. The proposed composite
hexagonal piezoelectric patch produces bending moments along the edges and a net transverse force at its
centre, which is balanced by point forces at the six vertices of the hexagon. The point force at the centre is
therefore collocated with the accelerometer sensor and this has two important control effects: first it improves
the stability properties of the feedback loop and second it enhances the active damping effect produced when
the feedback loop is closed. Both the open and closed loop properties of one and five feedback loops are
analysed in this study.
