Modeling and Analysis of Helicopter Ground Resonance Utilizing SymbolicProcessing and Dynamic Simulation Software

摘要

This thesis develops a technique for formulating the full nonlinear equations ofmotion for a coupled rotor-fuselage system utilizing the symbolic processing software MAPLE(registered). The symbolic software is further utilized to automatically convert the equations of motion into C, Fortran or MATLAB(registered) source code formatted specifically for numerical integration. The compiled source code can be accessed and numerically integrated by the dynamic simulation software SIMULINK(registered). SIMULINK(registered) is utilized to generate time history plots of blade and fuselage motion. These time traces can be used to explore the effects of damping nonlinearities, structural nonlinearities, active control, individual blade control, and damper failure on ground resonance. In addition, a MATLAB(registered) program was developed to apply the Moving Block Technique for determining modal damping of the rotor-fuselage system from the time marching solutions.