Operational mode-shape normalisation with a structural modification for small and light structures

摘要: Abstract When dealing with small and light structures, difficulties occur when measuring the modal parameters. The resonant frequencies are usually relatively high therefore a wide frequency range is needed for measurement. Furthermore, mass that added to structure by sensors causes structural modifications. To overcome these difficulties, an improved method using operational analysis instead of experimental proposed in this study. It derived from sensitivity-based mode-shape normalisation consideration variation. measurement excitation force not needed, because used only two simultaneous response measurements at unknown required. includes cancellation mass, resulting mode shapes unmodified structure. numerical results on structures compared analysis. comparison shows approach allows over increases accuracy also particular was advantages can be seen whenever accelerometer negligible variation occurs.