Applications of hybrid time–frequency methods in nonlinear structural dynamics

This paper presents a study on methods which may be used to compute the nonlinear response of systems whose linear properties are determined in the frequency or Laplace domain. Typically, this kind of situation may arise in soil–structure and fluid–structure interaction problems. In particular three methods are investigated: (a) the hybrid time–frequency method, (b) the computation of the convolution integral which requires an inverse Fourier or Laplace transform of the system’s transfer function, and (c) the identification of an equivalent system defined in the time domain which may be solved with classical time integration methods. These methods are illustrated by their application to some simple, one degree of freedom, non-linear systems and their advantages and drawbacks are highlighted.