Mathematical Modelling and Analysis of Nonlinear Aeroservoelastic framework for Light Aircraft

Abstract

In this research, an aeroelastic model of light aircraft is developed with the help of structural mesh from PATRAN and aero model in ZAERO. Flutter analysis of this aeoelastic model is performed in ZAERO and lowest flutter speed is identified along with critical mode shapes. The effect of freeplay motion of different control surfaces of aircraft are modeled and isintegrated with the flight control algorithm in MATLAB to obtain the aeroservoelastic model. The model thus developed is solved for numerous flight conditions and different freeplay angles of the control surfaces. Analysis for aileron, rudder and elevator are conducted independently and simultaneous analysis for aileron and elevator freeplay is also studied. It is observed that the aeroservoelastic response of light aircraft is most senstive to elevator while rudder has negligible effect on aeroservoelastic response of light aircraft. Moreover the simultaneous motion of two control surfaces reduce the lowest flutter speed of aircraft. Hence the effect of simultaneous motion of control surfaces need to be addressed during design of light aircraft.