Vibration Response Analysis of Gamma Ray Spectrometer

초록

Korea pathfinder lunar orbiter is being developed to operate in the moon orbit, including gamma ray spectrometer as one of payloads. The main function of gamma ray spectrometer(GRS) is searching for minerals which is covering the moon. Therefore, GRS is usually attached on outer surface of satellite to guarantee its view angles. For this reason, proper structural analysis should be carried out to verify its structural survivability on operational environments. In this paper, we introduce basic theoretical scheme using by single degree of freedom (SDOF) system to described the statistical approach for random vibrations. We assume that all random vibrations occurred in GRS are ergodic and stationary. And we use shock response spectrum approach which is used to analyze shock vibrations in spacecraft. We consider 3 different types of the GRS models with application of finite element method to obtain its stress. Furthermore, we calculate margin of safety of each model using Von-mises criteria to provide guideline of the suitable design for demands. Consequently, we figure all initial models can be used in given environmental specifications which are considered all possible loading case during launch and loop phase.