Finite Element Modelling and Simulation of the Hysteretic Behaviour of Single- and Bi-metal Cantilever Beams using a Modified Non-linear Beta-damping Model

This paper explores a novel non-linear hysteresis model obtained from the modification of the conventional Kelvin-Voigt model, to produce a non-viscous hysteretic behaviour that is closer to metal damping. Two case studies are carried out for a vibrating cantilever beam under tip loading (bending), the first considering a single uniform material and the second considering a bimetallic structure. The damping behaviour is studied in the frequency domain (constant damping ratio model vs. Kelvin-Voigt/ beta damping model) and time-domain (proposed modified hysteresis model vs. Kelvin-Voigt/ beta damping model). In the frequency domain, it was found that the Kelvin-Voigt model essentially damps out the displacement response of the modes more than the constant damping ratio model does. In the transient analysis, the Kelvin-Voigt model likewise produced unnaturally rapid damping of the oscillations for both the single- and bi-metal beam, compared to the modified hysteretic damping model, which produced a damping behaviour closer to actual metal behaviour. This was consistent with results obtained in the frequency domain.