In order to understand the various experimental approaches used to determine the modal parameters of a structure, some sort of outline of the various techniques is helpful in categorizing the different methods that have been developed over the last fifty years. One of several overlapping approaches can be used. One approach is to group the methods according to whether one mode or multiple modes are excited at one time. The terminology that is used for this is

• Phase resonanance (single mode)

• Phase separation (multiple mode)

A slightly more detailed approach is to group the methods according to the type of measured data that is acquired. When this approach is utilized, the relevant terminology is

• Sinusoidal input-output model (forced normal mode)

• Frequency response function model

• Damped complex exponential response model

• General input-output model

A very common approach to comparing and contrasting experimental modal analysis methodologies that is often used in the literature is based upon the type of model that is used in the modal parameter estimation stage. The relevant nomenclature for this approach is

• Parametric model

  • Modal model

  • [ M], [ K], [ C] model

• Nonparametric model

Finally, the different experimental modal analysis approaches may be grouped according to the domain in which the modal parameter estimation model is formulated. The relevant nomenclature for this approach is

• Time domain

• Frequency domain

• Spatial domain

Regardless of the approach used to organize or classify the different approaches to generating modal parameters from experimental data, the...