Experimental characterization of a hysteretic absorber for vibration reduction

The analysis of the dynamic behavior of mechanical systems is continuously expanding, as is the need to mitigate their response. Numerous studies have highlighted the beneficial effects of introducing nonlinear elements [1]. Since hysteresis often characterizes the behavior of structural components, this study investigates the use of a hysteretic absorber connected to the main structure. The addition of a hysteretic oscillator offers two main advantages: it introduces energy dissipation, and its nonlinearity promotes the occurrence of dynamic phenomena that redistribute energy in the structure [2]. The hysteretic vibration absorber (HVA) consists of a mass suspended by short cables, which exhibit hysteretic behavior under flexural deformation. The HVA is mounted on a vertical cantilever beam, representative of the barrier structure used along high-speed train lines. Cyclic tests and dynamic characterization of the HVA through experiments on a shaking table have been carried out. The parameters of a Bouc–Wen model of the device restoring force have been identified, showing satisfactory agreement between measured and predicted responses. Dynamic tests were performed to assess the free vibration response of the prototype structure with the hysteretic cable device installed at its top, under various initial conditions. The measured response was compared with that predicted by the identified two-degree-of-freedom model. The agreement is qualitatively excellent and quantitatively satisfactory. These results confirm the effectiveness of the HVA in significantly reducing the response of the main structure over a broad range of oscillation amplitudes. 1. F. Vestroni, C.H. Lamarque, H. Ding, The favourable role of nonlinearity in the dynamic response of mechanical systems - A Special Issue, Int. J. Non-linear Mechs, 165(4) 104795, 2024 2. F. Vestroni, P. Casini, Effectiveness and optimization of a hysteretic absorber for response mitigation, Nonlinear Dyn 2025, 11190-4