Quantifying Bearing Vibrations through Finite Element Modeling

Sammanfattning

This study investigates the relevance of using finite element method programsto quantify the magnitude of vibrations in the bearing houses of large machines.Simulations of relevant load cases were made in the ANSYS program, where thefrequency response at the desired points could be retrieved. The simulationswere mostly done by applying a magnetic force and an unbalance force to themachine, as well as applying boundary conditions representative of reality. Tocontrol the vibrations, an operating speed and an overspeed test were performed.The results show that the vibrations remain below the allowed level when themachine is running at operating speed. They also show that during the over-speed test, there are some frequencies that show spikes in the vibrations thatreach above the allowed levels.The study concludes that this method is worth further study. In future work,focus should especially be placed on the magnetic force, and optimally, it shouldbe done in conjunction with a vibration measurement performed in the lab. Theresults could then be directly compared to what is achieved in the testing.