Study On Dynamic Characteristics Of Bionic Vibration Isolation Platform With Multi-link And Energy Sink Coupling

Engineering equipment will deviate from the equilibrium position and chattering under external disturbance,which is called vibration.If these vibrations are not suppressed,it may cause great damage to the operation of the system.Therefore,the vibration isolation of the system is very important for the stable operation of the engineering equipment,which is the main reason that negative vibration isolation is always a hot topic in the research of engineering.In recent years,a series of bionic vibration isolation studies have been reported through the imitation of animal limb structure and movement,showing that bionic design is a promising idea for vibration isolation.In this study,based on the observation of the body motion of the kangaroo,from the perspective of bionic design,a three-degree-of-freedom vibration isolation platform(that is the protected object,the nonlinear energy sink and the X-shaped structure)is established.Then,the system dynamic equations are derived in the form of relative coordinates through Lagrange equations.Further,in the frequency domain,a set of algebraic equations of amplitude-frequency response are obtained by the Harmonic Balance Method,and then solved by Newton-Raphson iteration and the transmissibility are obtained.In addition,the time-domain response and energy variation of the system are studied and analyzed by the Runge-Kutta numerical technique.Approximate analysis solving and numerical analysis reveal that,(a)there are two resonance peaks with different characteristics in the whole frequency domain;(b)The results of time-frequency response show that there are complex nonlinear behaviors and resonance phenomena in dynamic response;(c)quasi-periodic motion may be a predictor of periodic steady-state response or strong resonance,and the displacement evolution before quasiperiodic motion may be used to distinguish the two phenomena.Simulation data in Adams validate the correctness of the theoretical analysis above.Besides,comparison results show that compared with the traditional and the same type of vibration isolation structure,the proposed structure has advantageous displacement transmissibility features in a wider frequency band.In summary,these results prove that the dynamic characteristics of the system are adjustable and designable in a specific frequency band,and can provide a practical method for improving the vibration isolation performance of engineering equipment.