Gregor JOAS
Conceptual design and construction of a vibration damper for ropeway cabins (in German)
This master thesis deals with the dynamic behavior of ropeway cabins and investigates the possibilities of passive vibration control of pendulum-type structures in the low-frequency range. Theoretical investigations show that liquid absorber devices are a promising methodology for this problem. The Tuned Liquid Damper (TLD)-Floating Roof (FR) is identified as the most suitable type of vibration absorber. After initially explaining the basics of ropeway construction, the theory of vibration and corresponding experimental methods is explained in more detail. Subsequently, a planar model of a cable car is set up and the equations of motion are derived. Investigations show that the first natural mode of vibration of this system can be represented as a mathematical pendulum for small deflections in a good approximation. Since the decoupled absorber system can also be described by a single degree of freedom system, the systems are combined, resulting in a model with two degrees of freedom. These are the pendulum system and the absorber. The pendulum-TLD system obtained is then verified by experimental investigations. The results clearly show that passive vibration control by means of liquid dampers can work for the considered system. Comparisons with a pendulum-Tuned Mass Damper system, known from literature, also show the same effectiveness of these systems with equivalent mass and absorber damping. The final investigations on a ropeway cabin show that the considered absorber can be used as an effective method for vibration mitigation in ropeway construction.