Reducing vibration isolation frequency in an X-shaped two-stage nonlinear system (Q6551794)

Attenuating unwanted vibrations via passive mechanisms is a strategy preferred in many engineering systems. This paper explores methods for vibration isolation using a two-stage approach. In [\textit{H. N. Song} et al., Energy 278, Article ID 127870 (2023; \url{doi:10.1016/j.energy.2023.127870})] design and implementation of a two-stage vibration isolation system for high precision equipment was explored. There the authors optimized the isolation performance by incorporating adaptive control and active-passive hybrids.\N\NThe primary purpose of the current paper is to carry out a through investigation of the performance of a two-stage vibration system that can be implemented in practical systems. This focuses in particular on the incorporation of nonlinearity into vibration frequencies, amplitudes and excitation sources. The nonlinearity opens up new options that perform better than traditional linear systems.\N\NThe authors explain their derivation of the dynamic model for a two-stage nonlinear vibration system and then use the incremental harmonic balance method to identify nonlinear solutions. The stability of solutions was addressed with Floquet theory. Then the model was validated with performance testing that examined the model's behavior and evaluated the isolation performance.