Tank vibration monitoring based condition evaluation is a technique which has a potential to detecting loose winding clamping conditions in power transformers. However, the existing knowledge on exact vibration behaviour of power transformer windings is scarce. Further use of laboratory experiments to full-fill this gap is also difficult due to the complex construction and dynamic operating conditions of the transformer. Hence, a reliable vibro-acoustic clamping pressure monitoring technique has not yet been developed. But, recent developments in finite element modelling based analytical simulation tools have made it possible to conduct accurate simulation studies of transformer winding vibrations. But developing a suitable geometrical model, which can optimize the required computational power and simulation time without reducing the accuracy is a challenge. This paper presents a detailed description of creating a simplified 3D geometry model of a disc type power transformer winding for mechanical vibration analysis. Finally, model and the simulations were validated using experimental modal analysis.