Time-accurate and Fast-running Model for Damaged Structures Aeroelastic Vulnerability Assessment

A fast-running and accurate fluid modal method is proposed to reduce the fully-coupled aeroelasticity problem of threat-damaged flight surfaces to a second-order multi-degrees-of-freedom ODE system. During Phase I, the fully-coupled aeroelasticity problem was formulated into a decoupled problem, and a technique for rapid extraction of nonlinear fluid modal mass, modal damping and stiffness of damaged and undamaged flight surfaces from a well-validated CFD solver was developed. The model was successfully validated using the experimental data for the flutter onset of the AGARD wing benchmark, and a rectangular wing with and without a hole. Phase II will fully develop the nonlinear fluid modal method to include more complex nonlinear contributions. Key control parameters will be identified to gain insight into the aeroelastic instability, and different techniques and flow solver methodologies will be investigated to improve the efficiency of extracting fluid properties. The developed tool will help evaluate the aeroelastic effects of threat-damaged flight surfaces for aerospace platform vulnerability assessments and define critical damage/flight conditions constituting a loss of load-carrying capability of the structure. The final delivered software may be executed by non-experts such that the aeroelastic/aerothermoelastic analysis may be applied to a wide variety of platform applications.