an analytical technique for solving nonlinear oscillators of the motion of a rigid rod rocking bock and tapered beams

in this paper, a new analytical approach has been presented for solving strongly nonlinear oscillator problems. iteration perturbation method leads us to high accurate solution. two different high nonlinear examples are also presented to show the application and accuracy of the presented method. the results are compared with analytical methods and with the numerical solution using runge-kutta method in different figures. it has been shown that the iteration perturbation approach doesn't need any small perturbation and is accurate for nonlinear oscillator equations.