ANALYTICAL METHODS FOR SOLVING STRONGLY NONLINEAR DIFFERENTIAL-EQUATIONS

In this paper various approximate analytical methods for obtaining sol utions for strongly non-linear differential equations in a complex fun ction are developed.The methods are based on the solution of the gener ating differential equation with a cubic complex term. The method of h armonic balance, the method of Krylov-Bogoliubov and the elliptic pert urbation method are adopted for solving strongly non-linear differenti al equations in a complex function. Three examples are analyzed. They describe the vibrations of a rotor with non-linearity. (C) 1998 Academ ic Press.