The Use of the Finite-Element Model to Prepare the Airbus A340-300 Ground Vibration Test

Within the framework of the Flexible Aircraft WP 2500 program a research ground vibration test on the Airbus A340 MSN 1 is scheduled for September/October 1999. It will be performed by a combined DLR/ONERA team. The main aim is to test new methods and improve existing ones in order to gain time at equivalent quality. Apart from experimental aspects, cost reduction concerning the number of pick-ups, exciters and exciter positions shall be analysed. The report covers the evaluation of accelerometer positions to ensure the observability and the evaluation and optimization of exciter configurations to guarantee the controllability of the modes of interest, on the basis of the FE model. By this means it is shown that the mathematical model provides considerable help to set-up and optimize a ground vibration test program. Furthermore, a relationship between the dynamic mathematical model and the measured degrees-of-freedom necessary to allow orthogonality tests is established using the FE model