Power Flow Analysis Of The Nonlinear Whole-spacecraft Vibration Reduction System

A method for calculating the vibration power flow is first proposed to study the longitudinal vibration of nonlinear whole-spacecraft vibration reduction system during the launch step.According to the power flow theory,the concentrating mass model and dynamic equations of the whole-spacecraft vibration reduction system are given,and the displacement response solutions of the satellite and the absorber are derived respectively.The power flow characteristics of the whole-spacecraft system with nonlinear vibration absorber are studied,including the input power flow into the whole-spacecraft and the power flow absorbed by the nonlinear dynamic vibration absorber.Then,the power flow absorption ratio of nonlinear dynamic vibration absorber and the maximum kinetic energy of satellite are defined to quantitatively evaluate the whole-spacecraft vibration reduction performance of a nonlinear vibration absorber under different parameters.Finally,the nonlinear shape memory alloy isolators are introduced to build the power flow measurement platform of the whole-spacecraft scaled model.The sine sweeping vibration experiment is conducted.The force and acceleration signals of the interface between the spacecraft and rocket are acquired.The transmitted power flow of the whole-spacecraft with or without isolators are calculated and compared.The power transmission ratio is defined and compared with the acceleration transmissibility.It shows the superiority of power flow transmission ratio as performance evaluation indicator.The energy transmission mechanism of the scaled model and the performance of the shaper memory alloy vibration isolator are analyzed.Results show that the power flow analysis method can better evaluate the vibration reduction performance of the nonlinear whole-spacecraft system and achieve the optimal design of the whole-spacecraft vibration reduction system in theory and experiment research.