LIMIT-CYCLE ANALYSIS OF A CLASS OF STRONGLY NONLINEAR OSCILLATION EQUATIONS

The limit cycle of a class of strongly nonlinear oscillation equations of the form u double over dot + g(u) = epsilon f(u, u over dot) is in vestigated by means of a modified version of the KBM method, where eps ilon is a positive small parameter. The advantage of our method is its straightforwardness and effectiveness, which is suitable for the abov e equation, where g(u) need not be restricted to an odd function of u, provided that the reduced equation, corresponding to epsilon = 0, has a periodic solution. A specific example is presented to demonstrate t he validity and accuracy of our method by comparing our results with n umerical ones, which are in good agreement with each other even for re latively large epsilon.