Spatial filter design for observation spillover suppression (fundamental investigation in vibration testing)

Spatial filter whose importance has been recognized is useful for suppressing modal observation spillover and making reduced-order model of the structures. The authors have proposed a design method of spatial filter of structures. The method is able to get rid of the selected modal amplitudes from measured responses in vibration testing. A small number of sensors are used to design spatial filter that are below number of the modes in target frequency range. In this paper FE-model based filtering methodology is presented. The following is the filter design procedure : a fundamental spatial filter is designed from FE-model of the structure, its experimental model is identified by using experimental modal analysis, and finally, spatial filter corrected by the experimental model is obtained. This paper installs the evaluation of optimal sensor position for establishing spatial filter. The workability of the method is investigated by experimental application to a cantilever beam.