Shear actuation mechanism and shear-based actuation capability of an obliquely reinforced piezoelectric fibre composite in active control of annular plates

In this work, the mechanism of shear actuation and the shear mode actuation capability of an obliquely reinforced piezoelectric fibre composite are investigated in active control of annular plates. This piezoelectric fibre composite is capable of providing extensional and shear actuation forces in a transverse plane of its Cartesian material coordinate system, and these actuation forces are utilized for shear-based actuation of an annular plate by embedding the piezoelectric fibre composite patches at the core of the plate. First, the mechanism of shear actuation of the annular sandwich plate is analysed, and it mainly reveals an adverse effect of the coupling between the transverse normal strain and shear stresses on the shear actuation forces, even though a good shear-actuated bending deformation of the annular plate is observed. So, next, the effectiveness of the piezoelectric fibre composite patches in shear mode active control of flexural vibration of the annular sandwich plate is investigated, where a shear-based feedback control arrangement is proposed for effective active control of the plate according to the velocity feedback control law. The analysis reveals an indicative shear actuation capability of this obliquely reinforced piezoelectric fibre composite, and thus it may be a potential material for shear-based active control of vibration of annular plates.