A novel method for detecting the position of nonlinear components in multi-degree-of-freedom nonlinear systems

摘要

Based on the Nonlinear Output Frequency Response Functions (NOFRFs), a novel method is developed to detect the position of nonlinear components in MDOF nonlinear systems. The validity of this method is demonstrated by numerical studies. Although the method assumes that the linear stiffness and damping for MDOF systems under study are known a priori, the results of the numerical studies indicate that, even if only approximate values of the linear stiffness and damping parameters are used, the method can still correctly detect the position of the nonlinear component. Since the position of a nonlinear component often corresponds to the location of a defect in a MDOF system, this new method is of practical great significance for fault diagnosis in mechanical and structural systems.