In recent years, topological optimization has become a powerful tool for designers and engineers in the technical world. The principle of this method is based on optimizing a given optimization region by minimizing or maximizing one or more objective functions, e.g. stiffness, mass, or natural frequency of the structure. For this reason, software companies developing CAD or FEM software have included topological optimization in their portfolio, either as a modular part of the software or as a dedicated program. In general, users of these programs do not have a mathematical definition of the software background, and it is not clear what variations in calculations may occur when using different software. For this reason, a comparative analysis of the selected software was performed to determine the differences between the results assuming the same boundary conditions and machine parts such as computing time, weight and volume.

At present, the unevenness of the cardan shaft, more precisely the Hook joint, can be described mathematically. This formulation of the non-uniformity is based on the knowledge of the angular velocity of the drive and driven shaft. However, there is no real understanding of how the non-uniformity affects the behavior of the drivetrain, in particular the vibration of the drivetrain. This paper describes an experiment that may shed light on this problem. Another contribution of this research could be to investigate how the length of the cardan shaft affects drivetrain vibration.

This paper describes an advanced design procedure used in the design of two test devices. The paper describes the use of advanced numerical modelling methods applying FEM. Emphasis is placed on the accurate determination of the natural frequencies and the natural shapes of the test equipment frames. Also, the operating frequencies of the partial working mechanisms were evaluated and then compared with the natural frequencies of the designed frames. The paper further describes the use of the data obtained from the FEM in the design of the test equipment itself. The paper compares two approaches to frame design not only for test equipment.