STEPPED MULTISINE MODAL TESTING USING PHASED COMPONENTS

The testing of structures using a stepped sine force excitation has been successfully used for many years. The major disadvantage of the method is the time required to step through each frequency of interest. This paper considers the problem of using a force input to a structure which consists of the sum of sinusoids. For a given power in each frequency component the relative phase of the components should be arranged to produce the minimum peak to peak amplitude. An algorithm to calculate these phases and examples of typical force input signals are given. Methods for extracting the frequency response functions are considered and demonstrated using a simulated example. Finally a simple hypothetical example is given to demonstrate potential experimental time savings over single stepped sine testing. © 1990.