Modal Analysis
A modal analysis calculates the frequency modes or natural frequencies of a given system, but not necessarily its full time history response to a given input. The natural frequency of a system is dependent only on the stiffness of the structure and the mass which participates with the structure (including self-weight). It is not dependent on the load function.
It is useful to know the modal frequencies of a structure as it allows you to ensure that the frequency of any applied periodic loading will not coincide with a modal frequency and hence cause resonance, which leads to large oscillations.
The method is:
- Find the natural modes (the shape adopted by a structure) and natural frequencies
- Calculate the response of each mode
- Optionally superpose the response of each mode to find the full modal response to a given loading
Read more about this topic: Structural Dynamics
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