Study Of Vibration Analysis And Optimization Methods For The Structure Of Missile-borne Module Circuit

To analyze the vibration performance and optimize anti-vibration ability for electronic equipments, is not only one of the main methods to improve the reliability in vibration working environment, but also an important prerequisite for the development of electronic technology. Focus on the missile-borne module circuit, this paper uses the method of numerical simulation to analyze its dynamics performance, and proposes the corresponding structure dynamic optimization method of electronic equipments, its purpose is to promote the anti-vibration ability of missile-borne circuits in the complex environment. This paper studies on following aspects:(1) Study on finite element modeling method for the module circuit. Tiny details and components are simplified off according to total mass equivalence method, which has little effect on the results. In the study of the fixed ways of model and the connection methods of components, we found that using fixed hole surfaces simulation screws, beam elements simulation connecting screws, and rivets simulation pin welding in software can simplify our modeling process, improve the computational efficiency, and guarantee the accuracy of numerical simulation at the same time.(2) Dynamic performance analysis for module circuit. Completed modal analysis for the circuit module by ANSYS Workbench. Simulation modeling methods are verified by the hammer blow and sweep experimental methods to ensure the correct analysis. The experimental results show that the results of the simulation analysis can be accepted and modeling method is effective and feasible. On this basis, the analysis of random vibration of the module circuit is completed, the acceleration response of the structure at a given input power spectrum is got.(3) Study on the optimization method of module circuit’s dynamic performance. Based on the small-deflection of thin elastic plate and transverse vibration theory, the natural frequency expressions are deduced before and after mounting components, and the theory is analyzed by using the simulation software. Theoretical and simulation results reveal that the natural frequency is determined by the components’ mass and installation locations after installating components. Besides, the effect that components’ positions generate, acting on the PCB’s natural frequency, is associated with vibration modes of original baseplate. The reduction is higher if the component is located where is large amplitude on baseplate, otherwise it is lower. Therefore, the optimization method of components’ layout for PCB’s natural frequency based on vibration modes is proposed, and applied in the module circuit, the example calculation shows that the natural frequency of each mode could be increased by more than 10% with the proposed method.(4) Research on the optimization method of random vibration response for module circuit. The random vibration response expression is obtained by the pseudo excitation method and derivated further, the influence factors are dig out. From these factors, the structure optimization methods are proposed, which are achieved on case models, and regulars are concluded from the analysis of example. Finally these methods are applied in the module circuit. According to the results of optimization, objective evaluation on the optimization method is made.