A comparison of two perturbation methods for vibrations of systems with quadratic and cubic nonlinearities (Q1329858)

The author discretizes a nonlinear partial differential equation and solves it by a perturbation technique. He notes that the process leads to inaccurate results in the case of the quadratic and cubic nonlinearities. He then proposes theories of a general nature that, perhaps for a general nonlinear system, should be softened.