In real life applications, machine parts and mechanical systems are rarely under static loading. Most of the time they are excited by dynamic loads. The structure responds to these dynamic loads according to its dynamic parameters such as natural frequencies and mode shapes. Therefore, an engineer has to have a solid insight into the dynamic behaviour of the structure which has been designed. The process of finding the dynamic behaviour of a structure is called structural system identification.
Structural system identification consists of finding the transfer function of the system which is established by finding the modal parameters of the structure such as, natural frequencies, damping, modal vectors, and residues.
The transfer functions of a structure can be obtained by mathematical modelling or by experimental methods. The experimental way to obtain the transfer function of a structure is achieved by measuring the response of the structure to a measured input. The responses are generally acceleration and the inputs or excitations are generally impulses or random/sine signals.
More information on the Modal Analysis application page.