Iterative receptance method for determining harmonic response of structures with symmetrical non-linearities

Abstract Although there are several techniques available for the harmonic vibration analysis of non-linear systems, the application of these methods to multi-degree of freedom systems is rather limited. In this study a new method (the Iterative Receptance Method—IRM) is developed for the harmonic vibration analysis of non-linear multi-degree of freedom systems with non-linear stiffness and damping forces. Different kinds of non-linearities are covered by expressing non-linear spring and damping forces as polynomials in displacements and velocities, respectively. Quasilinear receptance matrix of a non-linear system for a given level of external forcing is determined by using the receptance matrix of the linear part of the system and a matrix representing the non-linearity in the system. An iterative algorithm is employed in the numerical solution. The iterative receptance method is also modified for an efficient dynamic analysis of structures with local non-linearities. The application of the method is demonstrated by numerical examples, and the results are found to be quite encouraging for the application of the method to practical structures with large degrees of freedom.