Effectiveness and optimization of a hysteretic absorber for response mitigation

The response of a linear primary structure to harmonic excitation notably changes when a nonlinear device is added, similar to the case of a viscoelastic tuned mass damper. Here, a hysteretic absorber is considered, described by the simplest version of the Bouc-Wen model. The hysteresis nonlinearity of the added element strongly affects the response of the structure, investigated through a 2DOF system, depending on the closeness to internal resonance conditions, with differences in the modal interactions between the cases close to 1:1 and 2:1 internal resonances. With respect to the search for optimized solutions, a map for the optimal selection of the model parameters is defined, which provides a useful tool for absorber design and offers insight into the relationship among the absorber parameters. The analysis of the system behavior under impulsive excitation confirms the results obtained with respect to the performance of the optimized absorbers.