Initial situation
What happens when an excitation frequency is close to a natural frequency? A resonance situation arises and this is dangerous!
At the latest since 1941 the Tacoma bridge collapsed because of a resonance situation, one knows that such situations are dangerous. With rotating machines this can also lead to destruction. Here an example in a hydroelectric power station, which suspected a resonance situation at a bearing.
Procedure
By means of vibration analysis, it could be shown that it really was a resonance situation. However, the effects were not the same in all power ranges. The problem was particularly apparent in the higher load range and led to this range being avoided.
Due to the special design, the guide bearing could be stiffened laterally and thus significantly increase the natural frequency.
