Introduction -- Perturbation method (Lindstedt-Poincaré) -- The method of harmonic balance -- The method of Krylov and Bogolyubov -- The method of multiple scales -- The optimal homotopy asymptotic method -- The optimal homotopy perturbation method -- The optimal variational iteration method -- Optimal parametric iteration method.

This book presents and extends different known methods to solve different types of strong nonlinearities encountered by engineering systems. A better knowledge of the classical methods presented in the first part lead to a better choice of the so-called "base functions". These are absolutely necessary to obtain the auxiliary functions involved in the optimal approaches which are presented in the second part. Every chapter introduces a distinct approximate method applicable to nonlinear dynamical systems. Each approximate analytical approach is accompanied by representative examples related to nonlinear dynamical systems from various fields of engineering.