Fully automated vibration measurements of aircraft fuselages in the mid-frequency range

Abstract

In order to analyze the dynamic behavior of aircraft fuselage structures in the mid to high frequency range a large number of measurement positions is necessary. This is especially true if advanced methods of evaluation like structure intensity analysis (STI) are to be used. The amount of measurement positions necessary for the vibroacoustic evaluation of full sized aircraft fuselage structures has previously been shown to be in the order of multiple thousands requiring extensive measurement campaigns using hundreds of rowing sensors and a large team working for weeks. Presented here is a novel approach to Laser-Doppler-Vibrometer (LDV) based measurements of aircraft fuselages. A mobile laser scanning system capable of fully automatic vibration measurements of fuselage sections using a commercial single-point LDV was developed. The system can be deployed within the excited structure due to its vibration isolation and is able to autonomously match a predefined measurement geometry with the real structure using only a couple of reference markers.