Identification Techniques for Nonlinear Differential Equations of Motion

Abstract : This report develops and systematically demonstrates by computer simulations new nonlinear system stochastic techniques to determine the amplitude-domain and frequency-domain properties of nonlinear systems as described in proposed nonlinear differential equations of motion. From measurements of input excitation data and output response data, it is shown that this new method, based upon multiple-input/single-output (MI/SO) linear analysis of reverse dynamic systems, allows for the efficient identification of different nonlinear systems. Nonlinear systems simulated here include Duffing, Van der Pol, Mathieu, and Dead-Band systems. Keywords: Degrees of freedom, Civil engineering.