Speed sweep analysis (also known as 'transient vibration analysis') is a very powerful method of determining the vibration characteristics of the structure. In this procedure, the machine speed and vibration are measured during a speed run-up or run-down. This procedure maps the vibration amplitude and frequency to the machine speed. From the results the problem can be tracked to a rotating component or to a resonant condition.
The advantage of this method, as compared to modal analysis and finite element analysis, is that the dynamics of the structure is measured at operating conditions. This will include thermal effects as well gyroscopic effects of the operating machine.
Much insight into the characteristics of the structure can be gained from these measurements. In particular, the resonant characteristics will be much better known. Speeds at which operation should be avoided can also be determined.
(back | glossary)