Study On Piecewise Linear Stiffness Energy Sinks For Space Optical Remote Sensing Payload

During the launch phase,the space optical remote sensing satellite will experience a series of vibration environments,such as the launch vehicle vibration and the detonation of initiating explosive devices,which may cause excessive vibration of the optical sensitive parts,with bad effect on optical remote sensing load and even permanent damage.As the lightweight extent of optical load becomes much lighter,the traditional vibration reduction technology has been difficult to meet the harsh requirements of optical load on the vibration environment.As a new type of passive damping device,nonlinear energy sinks has been applied to the vibration abatement of space equipment more and more for its high energy dissipation efficiency,strong robustness and small mass.Based on the practical engineering needs,this paper studies the single-degree-of-freedom nonlinear energy sinks with piecewise linear stiffness.The main research contents of this paper are as follows:In this paper,the piecewise linear stiffness energy sinks energy dissipation efficiency under impact load is studied.The slow variation equation of the two-degree-offreedom system with coupled piecewise linear stiffness energy well under impact load is derived by means of the complex average method.The approximate analytic expression of the extreme point of the slow invariant manifold is obtained with the method of approximate substitution.Based on this,an optimization model for energy dissipation efficiency is established.The numerical analysis shows that the energy dissipation rate of the optimized piecewise linear stiffness energy sinks increases significantly.The two-degree-of-freedom model of the coupled piecewise linear stiffness energy sinks under simple harmonic excitation is simulated numerically,and the influence of the main structural parameters of the piecewise linear stiffness energy sinks on the vibration abatement effect is analyzed.Based on this,a parameter selection method for simple harmonic excitation is established,which can quickly design parameters for piecewise linear stiffness energy sinks,and the usability of the parameter selection method is verified by numerical simulation.Aiming at the vibration suppression requirements of an optical remote sensing load,according to the optimization model and parameter selection method,the parameters of the device are determined in this paper,and a principle prototype of a piecewise linear stiffness energy sinks is designed.The permanent magnet vibrator of the prototype is both the vibrator and the damping component,which makes the stiffness of the energy sinks adjustable in a certain range through the gasket.After testing the main parameters of the energy sinks,the installation and debugging of the prototype is completed.In order to verify the vibration suppression effect of the piecewise linear stiffness energy sinks designed in this paper,it is installed in an optical remote sensing load for impact and sinusoidal vibration tests.Under the condition of impulse excitation,the vibration dissipation time of the space camera secondary mirror is reduced by up to 46.9% after installing the piecewise linear stiffness energy sinks.Under sinusoidal excitation condition,the peak acceleration response of the primary mirror of the space camera decreases by 18%,while that of the secondary mirror decreases by 15%.The experimental results indicate that the analysis conclusion of the analysis of piecewise linear stiffness energy sinks given in this paper is correct,the parameter optimization model and the selection method are effective,and the piecewise linear stiffness energy sinks can effectively suppress the vibratory response of space optical load under impact and sinusoidal excitation.