Modal testing: Difference between revisions

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[[File:Vibration testing.svg|thumb|upright=3|Key components for performing experimental modal analysis.]]

'''Modal testing''' is the form of [[vibration|vibration testing ]] of an object whereby the natural (modal) frequencies, modal masses, modal damping ratios and mode shapes of the object under test are determined.

A modal test consists of an acquisition phase and an analysis phase. The complete process is often referred to as a [[Modal Analysis]] or Experimental Modal Analysis.

There are several ways to do modal testing but impact hammer testing and shaker (vibration tester) testing are commonplace. In both cases [[energy]] is supplied to the system with a known frequency content. Where structural resonances occur there will be an [[Amplifier|amplification]] of the response, clearly seen in the response spectra. Using the response spectra and force spectra, a [[transfer function]] can be obtained. The transfer function (or [[frequency response function]] (FRF)) is often [[curve fitting|curve fitted]] to estimate the modal parameters; however, there are many methods of modal [[Estimation theory|parameter estimation]] and it is the topic of much research.[[File:Vibration testing.svg|thumb|Key components for performing experimental modal analysis.|center|636x636px]]

== Impact Hammer Modal Testing ==