Analysis and design of passive band-stop filter-type vibration isolators for low-frequency applications

The aim of this paper is to design a stiff and lightweight passive vibration isolator that has wide stop-band at low frequencies. First of all, bandwidths of single-degree-of-freedom (sdof) dynamic vibration absorbers and lever-type anti-resonant vibration isolators are formulated in a general framework. Then, by making use of these formulations, a 2dof vibration isolator is synthesized to obtain large bandwidth at low frequencies. It has been shown that inertial coupling was beneficial in obtaining a stiff and lightweight design. More importantly, asymmetry in the inertial forcing terms generated by the levered masses yielded a vibration isolator that has two anti-resonance frequencies in its stop-band. Finally, bandwidth improvement over the previously analyzed isolators is demonstrated via numerical examples.