Vibration reduction is a critical necessity in many fields of engineering, technology, and industry. As a result, there is a need for vibration management. To restrict or adjust the system's vibration response, a variety of techniques are employed. In recent years, there has been a lot of enthusiasm for the easy implementation of these vibration-control structures. The damping properties of viscoelastic materials tend to be excellent. Damping is determined by the material's ability to dissipate energy. To minimise the vibration of vibrating surfaces, viscoelastic materials are commonly used. In this study, viscoelastic material (Dyad 606) is applied on the AL plate in the form of free layer damping and pretension layer damping. First aluminium structure using free layer damping and another one using pretension layer damping by applying tension load (two layers of damping plates, one on the top surface of the Al alloy and the other on the lower face). Passive vibration damping of the plate is achieved. These layers are influenced by axial uniform distributed load. The damping behaviour of the AL Plate is discussed in relation to the thickness variation of the pre-tension damping material. The results show that the loss factor and the attenuation percentage of the structure with pretension layer damping are increased as compared to free layer damping. It is also found that the most effective thickness of the damping material to increase the damping capacity of the framework is around half the base plate thickness