A Certain Type Of Avionics And Installation Of Aircraft Dynamics Analysis

Airborne electronic equipments are the important parts of the aircraft system. Those equipments are worked in vibration and impact condition. According to American Military statistic, vibration effect is about 27% in resulting failure of electronic equipments. In order to enhance the airborne electronics' reliability, the comprehensive dynamic analysis of them is necessary.This thesis takes one type of airborne electronic equipment as an example, dynamic analysis are implemented based on finite element method.Firstly, the finite element model of the airborne electronic equipments was established. The structure of the airborne electronic are sophisticated. They not only have frame structure but also printed circuit board. Further more, the type of components is multitudinous and distributed situation is complex. This thesis analyzes the key steps in the finite element modeling process, and studies the modeling method for airborne electronic equipments. For the module level, detail modeling and global mass smearing methods are used to establish finite element model. For modeling the finite element model of equipment level, global mass smearing method is used.The dynamic modal analysis was done based on the finite element method. The natured frequency and mode shape of the equipment as well as its module were obtained. Compared with that of the experiment testing result, the finite element models were modified until they match with that of the experimented testing result.Followed by the above qualified finite element models, the random vibration analysis and transient analysis were deal with. The obtained include the acceleration power spectral density of some key position of the electronic equipment, displacement nephogram, and acceleration response of some sensitive and critical components. The dynamic characteristic of the airborne electronic equipment was obtained.The bracket whose function is fixture and support is the interface between the electronics equipments and aircraft. According to the current design dimension, the bracket is modeled by finite element software, which is verification by test data. Then, modal analysis and random vibration analysis are carried out. At last, the shape and dimension optimize design are performed to reduce weight, enhance stiffness and reduce the stress in random vibration.This thesis deals with dynamic analysis of airborne electronic equipments based on finite element. The results offer useful reference for electronic equipments structure design and PCB layout, and this method have also some reference values to the design and analysis of electronic equipments.