Research On Dynamic Response Of The Electronic Equipment With Rubber Shock Absorber On The Rockets

Rocket-borne electronic equipments are important parts that realize the control of rocket.In the stage of structure design,FEA is an important meansure to evaluate the adaptability of rocket-borne electronic equipments working in the bad mechanical environment.At present,the following difficulties exist in the FEA of the electronic equipments on the rocket: firstly,rubber dampers are usually installed in the electronic equipments on the rocket to improve its adaptability to the harsh mechanical environment such as vibration and impact,but the high nonlinearity of rubber material makes the modeling of the rubber dampers difficult in the FEA;Secondly,there are hundreds of electronic components on the internal PCBs of arrow-borne electronic equipment,and PCBs are fixed in the cabinet through complex locking mechanism,then how to balance the relationship between calculation scale and accuracy of PCB components in the process of modeling is also the difficulty of dynamic response analysis of arrow-borne electronic equipments.Based on the theory of structural dynamic response and finite element method,the finite element model of rocket-borne pallet electronic equipment is established by ANSYS and the dynamic response analysis is carried out.In this process,according to the existing test conditions and limited material parameters,two concise and practical modeling schemes for ZN-35 rubber shock absorber under wide-band and small-amplitude application conditions are proposed: one is springdamper element modeling method based on dynamic characteristics test of rubber shock absorber,the other is constitutive model modeling method.The validity of the two modeling methods are verified by experiments.Based on the idea of combining the local fine modeling with the equivalentmass,a modeling method suitable for the internal circuit components of the rocketborne electronic equipment is proposed.The constraints of the circuit components in the equipment are simulated by using the methods of feature modeling,local node degree of freedom coupling and local node merging.By comparing PSD response spectrum obtained under the condition of random vibration with the random vibration test results,the correctness of the dynamic analysis results and the finite element model of the electronic equipment on rocket which are established are verified.