Chaotic and nonlinear dynamic response of aerosurfaces with structural nonlinearities

Anthony J. Hauenstein*, James A. Zara** McDonnell Douglas Missile Systems Company P. 0. Box 516 St. Louis, Missouri 63166 Walter Eversman+. Iyad K. Qumei++ Mechanical & Aerospace Engineering Department University of Missouri-Rolla Rolla, Missouri . 6540 1 An analytical and experimental investigation of aerodynamic surfaces with discrete root structural nonlinearities was performed. This paper discusses the design, development, analysis and wind tunnel testing of the rigid aerosurface used. The objective of the activity was to assess the influence of various system parameters and aerodynamic conditions on nonlinear response, including chaotic behavior. Five types of response were observed in both analyhcal and experimental results. These were damped decay, chaos, nonharmonic response, periodic limit cycle, and flutter. The type and intensity of the response is highly dependent on magnitudes of freeplay and the degree of coupling between aerosurface pitch and plunge motion, and airspeed. The overall correlation between analyhcal and experimental results was generally good. * Senior Specialist, Member AIAA * * Principal Manager, Member AIAA + Curators' Professor, Member AIAA & ASME + + Graduate Student, Member ASME