Ground Vibration Testing of Very Flexible Aircraft

Student : Bilal Sharqi

Sponsor : Center for Unmanned Aircraft Systems (C-UAS)


Ground Vibration testing (GVT) is a method for determining the modal parameters (frequencies, damping, and mode shapes) of a structure. A GVT is helpful in guaranteeing the aeroelastic and aeroservoelastic stability of new and untested aircraft, as data generated via GVT can be used to compare, validate, and update computational aeroelastic models for structures.

In this project, a GVT is performed on the X-HALE testbed, a very flexible aircraft developed at the University of Michigan’s A2SRL. Modifications made over the course of the X-HALE project necessitate better validation and understanding of the analytical vibration and flight control modes. A very flexible aircraft like the X-HALE also exhibits nonlinear coupling between the rigid body and elastic degrees of freedom, and validation of the models is necessary for effective design, simulation, and control.

Primary focuses of this research are the experimental and numerical analysis of the effects of suspension parameters and deformation on the modal data and updating the numerical models to better correspond with the experimental data.

Figure 1: GVT Setup of the RRV suspended in the Outboard configuration
Figure 2: The X-HALE suspended in two different configurations showing nonlinear deformation