When digital twins are becoming important in a specific technical area, they have of course to represent the real physical behaviour of parts and assemblies as good as possible. Therefore, testing of real structures is becoming important, too, in order to update the simulation model of the digital twin for getting a satisfactory prediction of the physical behaviour. This also holds for Finite Element Analysis (FEA), where test results can be used to update the FE model for better representation of the structural behaviour. In addition, simulation results can be used to identify the best locations on the structure to measure certain results. This is of particular interest in vibrational testing and simulations with forced vibrations, where the time dependent excitation is to be defined for a wide application range. Standard vibration tests using the sine sweep method [1] is a promising means to identify the vibrational characteristics of a part or assembly in both testing and simulation domains. A sine sweep is a forced vibration in time domain which uses defined amplitudes and runs over a given frequency range, where each point in time refers to exactly one frequency. This allows for an excitation with results in the time domain and provides also results in the frequency domain. This makes the sine sweep method perfect for test and simulation in both domains with a direct comparability. The paper will use a full solid model of a transmission to demonstrate the use of the sine sweep method in FE simulations. Key results of structural dynamics and fatigue analysis are presented. In addition, the correlation between time and frequency domain is demonstrated as well as the comparison of the results from a time-history response analysis and from a random response analysis. Because the transmission is a bolted and prestressed assembly, structural dynamics is based on a nonlinear contact analysis with a subsequent linearization to achieve a linear dynamic model for applying the sine sweep method. All simulations will be performed with the commercial FEA software PERMAS, which beside contact analysis also supports the linearization process and the dynamic analyses in time and frequency domain. In addition, it also integrates fatigue analysis to identify critical areas of higher damage.