The Damping Mechanism of Steel-Rubber Composite Beam under Flexural Dynamic Excitation

摘要

Damping is one of the several important parameters in the dynamic system. It reduces amplitude response of a structure, especially around the resonance. The higher the damping, the better the performance (more comfort, lower stress, less fatigue), and the longer the life cycle of the structure will be. There are many types of damper amongst other is the tuned mass damper (TMD), where mass and spring are designed in such that the TMD frequency is close to the natural frequency of the structure in question where the phase angle is about 180 degree out of phase. Applying steel-rubber composite beam as a damper in the TMD system is expected to increase the damping of the structure of interest. The objective of this study is to test experimentally and numerically the dynamic parameters of the rubber-steel composite beam upon a cantilever support system under static load-displacement test and flexural dynamic excitation. The addition of steel (in the form of wire mesh) embedded in the rubber beam significantly increases the stiffness, but the damping ratio, at a small range of displacement. The effectiveness of rubber material in the steel-rubber composite beam is expected when large displacement occurs, meaning that more energy dissipation and larger damping ratio. The established numerical model is able to generate dynamic parameters close to results of the experimental model, but the damping ratios.