Vibration analysis and control of smart composite plates with delamination and under hygrothermal environment

An analysis of delaminated composite plates with integrated active fibre composite (AFC) actuators and sensor under hygrothermal environment has been undertaken in the present work. The top and bottom plies of the laminate constitute AFC actuators and sensors. In the present investigation, hygrothermal loading is taken into consideration, and the effect of moisture and temperature on the delaminated plate structures is analysed. The minimum total potential energy approach is used for arriving at the governing equation. A finite element model for centrally located delamination is developed on the basis of first order shear deformation theory. An eight noded serendipity element with five degrees of freedom per node is considered for the finite element formulation. A parametric study on the effect of stacking sequence, boundary conditions and environmental conditions in the presence of delamination on the laminated plate is studied. The key observations from the parametric study are: there will be reduction in natural frequencies in the presence of delamination and/or hygrothermal loading, and reduction in structural stiffness due to the presence of delamination can be negated by applying voltage to the active fibre actuator layer.