In this paper numerical analysis of the transformer sheet metal clamping system was implemented. Load bearing frame of clamping system allows clamping of sheet transformer core plates resulting in a compact form the core of the transformer. During the operation of the clamping mounting system via flange and / or screws, the frame must submit a static load that occurs during clamping plates transformer cores. Aim of this paper is the development of numerical finite element method model in ANSYS software package that will verify the current analytic calculation of the clamping system of transformer core sheets by the company Končar Power Transformers (KPT). For this reason, it is necessary to make a detailed analysis and verification approach applied in the preparation of the numerical model. Such a model will enable better flexibility when simulating the mechanical responses of various types of loads and load-bearing structures. The work is divided into nine sections. In the introduction, analyzed problems and main parts of the transformer are shortly explained. In the second part, function of the clamping system sheets transformers and nonlinear behavior of transformer cores is described. In the third part, theory of structures on elastic foundation, which will be applied in the development of numerical model is explained. The fourth part briefly describes the finite element method and 1D, 2D and 3D finite elements used in the work. In the fifth part, used incremental-iterative method for the calculation of non-linear analysis is described. In the sixth part, with five examples used finite elements and methodology of beams resting on linear or nonlinear elastic foundations are verified. In the seventh part, way of making the numerical model is described and results of numerical analysis of two selected examples are shown. The remaining load cases can be seen in the document attachment V. In the eighth part, analogous numerical model is shown, but with the application of 3D finite element. Finally, in the ninth chapter, a conclusion on the results of the numerical model is made.