Seyed Mohammad Navid Ghoreishi; Mohammad Aminjafari; Amir Sedaghati; Ehsan Zabihian
Abstract
The structure of a satellite, during its operational life, should be tolerated all applied mechanical loads which the most important of them is vibration loads during the launch. To verification of design process, finite element analysis and vibration tests should be performed on the structure of satellite ...
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The structure of a satellite, during its operational life, should be tolerated all applied mechanical loads which the most important of them is vibration loads during the launch. To verification of design process, finite element analysis and vibration tests should be performed on the structure of satellite according to the ECSS standard. In this paper, while simultaneously examining the optimal design process for a satellite structure with an increase in the strength to mass ratio, the required finite element analyzes along with the mechanical tests of the structure of a telecommunication satellite, including random vibrations, sinusoidal vibrations, shock and quasi-static, are fully presented. The results showed that by employing the cross section design for the satellite structure, the natural frequency of the satellite in the longitudinal direction have increased appreciably, which increases the strength of the satellite in the longitudinal direction. The experimental results proved that the designed structure meets the frequency requirements of the launcher while tolerate the mechanical loads during launch. Also, the experimental results were in good agreement with the numerical results, including the modal analysis, random and sine vibration. Therefore, design processes of the satellite structure were verified by experimental tests.
Control dynamics
Ehsan Maani miandoab; Ehsan Zabihian; Hossein Najafi
Abstract
In all types of satellites, communication systems are utilized for data transmission between satellite and ground stations. pointing the communication antennas to the ground is necessary for the correct mission transmission information. The vibration of the satellite antenna leads to the deform antenna ...
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In all types of satellites, communication systems are utilized for data transmission between satellite and ground stations. pointing the communication antennas to the ground is necessary for the correct mission transmission information. The vibration of the satellite antenna leads to the deform antenna pattern, creating noise and reduction of connection quality. Moreover, working the attitude control actuators near the antenna's natural frequency leads to its resonance and large amplitude vibration in the antenna and satellite structure. Thus it is necessary to identify the satellite antenna dynamic behavior as natural frequency and damping ratio. In this paper the satellite antenna is intended as a smart beam, based on the free vibration of clamped-free beam shape of satellite antenna and sensing its vibration by the piezoelectric sensor, its dynamic characteristic as damping and frequency is identified and verified by comparing the results with experimental ones. The considered mathematical model has very accurate and this model can be used to determine the dynamic behavior of the antenna in different satellite secondary structures.
