Research on the effects of raft on vibration isolation

Abstract The floating raft vibration isolation system includes upper and lower isolators middle raft. As one of the most important parts that affect performance isolation, is usually assumed to be an undamped or viscous damping structure in analysis, which different from actual situation. To study effects with hysteresis characteristics, a three-freedom complex stiffness mechanical model was built, approach for calculating raft's force transmission rate derived impedance methods. Based on large-sized raft, we analysed mass, through numerical calculation. Results show increasing mass improved over frequency ranges; increase contributed ranges near its low-order natural frequencies, while reduced higher greater led enhanced at frequencies ranges.