Order in chaos (Q1063454)

This paper is intended as a tutorial survey on a rather new field of research which can have important applications in mechanical engineering. It is concerned with chaos in the technical sense of the word, i.e., more precisely speaking, with deterministic chaos. Two classes of problems are dealt with: (1) Study of deterministic chaos by means of model equations and in particular, how to characterize chaos. (2) How to determine the characteristic features of chaos from experimental data. As model equations the already mentioned Lorenz equations have been used which are autonomous. Examples of nonautonomous equations giving rise to chaos are the Helmholtz and the Duffing equations. For small driver amplitude A these equations can be solved by methods of perturbation theory, whereas in the chaotic regime a numerical integration is required.