How to Determine the Modal Parameters of Simple Structures

The modal parameters of simple structures can be easily established by the use of PULSETM, the Multianalyzer System Type 3560. This application note describes how to measure the modal frequencies by inspection of frequency response functions, how to determine the modal damping with the aid of the frequency weighting function included in the analyzer, and how to establish the mode shapes by examining the value of the imaginary part of the frequency response function.