NONLINEAR JOINT PARAMETER-IDENTIFICATION BY APPLYING THE FORCE-STATE MAPPING TECHNIQUE IN THE FREQUENCY-DOMAIN

In this work, a method is suggested to identify non-linear joint prope rties from measured frequency response functions (FRFs) at the non-lin ear joint connection points of the structure. Nowadays, the force-stat e mapping approach is frequently used to identify non-linear parameter s within a structure. The method fits the time domain joint forces dir ectly to the joint force model. But the method has some limitations in application to complex real structures because it uses a time domain lumped parameter model. In this study, a frequency domain approach is employed in order to overcome the limitations. The proposed method is easily applicable to a complex structure having non-linear joints sinc e it uses each substructure's FRF in the frequency domain. The validit y of the proposed method was tested numerically with a 3 dof system ha ving non-linear joints.