Non-linear identification of multi-degree of freedom systems using the restoring force surface method

Abstract

In order to facilitate the non-linear identification of aircraft structures using the multi-degree of freedom restoring force surface method, a research study has been conducted to investigate the results accuracy of non-linear identification of multi-degree of freedom systems. This paper reviews the theoretical background of the restoring force method and explains its advantages and disadvantages together with practical consideration for its application. Focus is put on some practical aspects of the realization of non-linear identification, e.g. the type of excitation force signals, the required sampling rates, signal processing issues, etc. The validation of the approach is pursued by processing simulated response data of multi-degree of freedom system with known non-linearity.