By attaching initially stressed poly vinyl chloride (PVC) layers on the flexible structures, necessary passive damping can be provided. Using passive constrained layers on these PVC layers, the efficiency can be made even better than ordinary passive constrained layer damping (PCLD) treatment. By using stressed PVC layers, a rich performance in case of circuit failure conditions is always available. An active constraining layer further enhances the damping performance of this passive technique. Precompressed layer damping treatment augmented with active constrained layer damping (ACLD) treatment has been suggested, which has many desirable features as compared to existing pretensed layer damping treatment. Such enhancement in damping performance is not possible by conventional ACLD as well as PCLD techniques. The effect of initial strain (compressive or tensile) and other parameters of the PVC layers on the vibration characteristics of flexible structure have been investigated. The Hamilton principle in conjunction with finite element method is used to derive the differential equations of motion. Using proportional feedback controllers, the complex closed loop eigenvalue problem is developed and solved numerically. The effectiveness of the proposed technique has been validated experimentally using a digital linear quadratic Gaussian controller.