**Modeling**

**Structural Model**

Modeling aeroelastic behavior of flexible aircraft requires the development of a structural model coupled with an aerodynamic model. The nonlinear aeroelastic models are derived based on structural finite elements and lifting surface theory, both of which are available in general purpose commercial code. However, accurate flutter prediction is highly dependent on the accuracy of these aerodynamic and structural models. It is standard practice to improve the accuracy of structural models by updating the parameters in the finite element model using experimental modal data.

**Graduate Student**: Abhineet Gupta

**Publications**:

- A. Gupta, P. Seiler and B. Danowsky Ground Vibration Test on A Flexibble Flying Wing Aircraft, AIAA Science and Technology Forum, 2016.
- A. Gupta, C. Moreno, H. Pfifer, B. Taylor and G. Balas, Updating a Finite Element Based Structural Model of a Small Flexible Aircraft, AIAA Science and Technology Forum, 2015.
- C. Moreno, A. Gupta, H. Pfifer, B. Taylor, and G. Balas, Structural Model Identification of a Small Flexible Aircraft, American Control Conference, pp. 4379-4384, 2014. (mfiles)

**Aeroservoelastic (ASE) Model**

A modular, subsystem based approach is adopted to model an ASE system. Aerodynamic and structural models of the aircraft are developed independently of one another, and interconnected suitably to model the impact of structural deformation on aerodynamic loads and vice versa. This approach has significant advantages over a fully integrated model primarily since it provides an opportunity to choose and work with individual subsystems independently. The fidelity of each subsystem can be chosen independently, and the underlying methodology of every subsystem can also be different. For instance, the aerodynamic model can be kept linear while a nonlinear model may be chosen for structural dynamics or vice versa.

**Graduate Student**: Aditya Kotikalpudi

**Publications**:

- H. Pfifer and B. Danowsky, System Identification of a Small Flexible Aircraft , AIAA Science and Technology Forum, 2016.
- A. Kotikalpudi, H. Pfifer and G. Balas, Unsteady Aerodynamics Analysis for a Flexible Unmanned Aerial Vehicle , AIAA Atmospheric Flight Mechanics Conference, 2015.
- M. Leitner, A. Knoblach, T. Kier, C. Moreno, A. Kotikalpudi, H. Pfifer and G. Balas, Consistent Model Generation of a Body Freedom Flutter Vehicle for Multidisciplinary Analyses, AIAA Science and Technology Forum, 2015.
- A. Kotikalpudi, C. Moreno, B. Taylor, H. Pfifer and G. Balas, Low Cost Development of a Nonlinear Simulation for a Flexible Uninhabited Air Vehicle , American Control Conference, pp. 2029-2034 2014.