Applicability of Force Appropriation for Mode Tuning of Aircraft

Kurzfassung

For the nonlinear characterization of modes, methods with harmonic excitation such as PLL and CBC have been proven useful. However, modal isolation for this purpose is required. This work investigates how modal isolation is achieved with appropriate shaker placement and force vectors. Different methods to compute optimal force pattern are revised and also one additional method based on the modal response is proposed in this work. The method discussed requires a modal modal which is available from a linear identification of the structure or a finite element model. It is shown on a FE model of a glider how the first four modes are isolated by proper placement of shakers and choice of force vectors. The proposed methodology improves the preparation of nonlinear identification based on experimental continuation during a GVT.