Zahra Khaji; Mahdi Fakoor; Saeed Shakhesi
Abstract
The design of space operations must be done carefully. Because the smallest mistake in the design and construction of the spacecraft causes heavy financial losses. Electronic boards are one of the most important components of electronic systems in any operation. These boards must continue to operate ...
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The design of space operations must be done carefully. Because the smallest mistake in the design and construction of the spacecraft causes heavy financial losses. Electronic boards are one of the most important components of electronic systems in any operation. These boards must continue to operate under the applied loading. Strong levels of random vibrations can cause damage and fracture in electronic boards. The random vibration field applied to the electronic board can be modeled by mixed-mode I/II loading. Solder joints are very sensitive components of satellites. Fracture of electronic packages often occurs due to cracking in the joint between the electronic board and the solder under mixed-mode I/II loading. In this research, a new fracture criterion based on the maximum tangential stress is presented to predict the fracture for the interfacial crack between the electronic board and the solder. Based on the presented criterion, the direction and moment of crack initiation are predicted for the interfacial crack between isotropic and orthotropic materials. In this way, the fracture limit curve can be drawn. By comparing the presented criterion with the available experimental data, it can be concluded that the presented criterion has sufficient validity to evaluate the prediction of fracture in interfacial cracks between isotropic and orthotropic materials.
Space engineering
Roya Sanaie; Pouya Talebinejad; Seyed Mohammadjavad Tabatabiee; Mahdi Fakoor
Abstract
The solar array ,one of the main parts of the satellite's electrical power subsystem, is responsible for providing the required electrical power for the satellite during the mission. Micrometeorites and small space debris are considered serious risk for the satellite mission. Due to the number of satellites ...
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The solar array ,one of the main parts of the satellite's electrical power subsystem, is responsible for providing the required electrical power for the satellite during the mission. Micrometeorites and small space debris are considered serious risk for the satellite mission. Due to the number of satellites in orbit, space debris is increasing. The impact of micrometeorites or orbital debris on the solar panels of the satellite can damage the internal structure of the panel, which causes a drop in the electrical power of the satellite. In this article, along with the numerical and geometrical simulation of the solar panels of the MEO communication satellite, an algorithm based on the direct random impact of micrometeorites and orbital debris on the solar panels has been presented, and their damage rate has been calculated. The size of meteorites and space debris is determined based on the average size of the particles in the earth's orbit. After summarizing the collision results, the redundant solar panel has been simulated based on the minimum and maximum damage to compensate for the satellite power loss. The results show that the redundant solar panel can compensate the loss of satellite power after the collision and estimate the extent of damage as soon as possible
dynamics
Hossein Maghsoudi Dehaghani; Amirreza Kosari; Mahdi Fakoor; Masoud Khoshsima
Abstract
Due to the unique characteristics of the geostationary orbit and the importance of establishing a satellite in this flying corridor، it is necessary to investigate the effect of environmental disturbances on the orbital elements and to maintain the satellite orbital elements in order to increase the ...
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Due to the unique characteristics of the geostationary orbit and the importance of establishing a satellite in this flying corridor، it is necessary to investigate the effect of environmental disturbances on the orbital elements and to maintain the satellite orbital elements in order to increase the longevity and operation of a satellite in this orbit. A satellite in earth orbit is always exposed to various environmental disturbances such as earth gravity gradient force، gravity of the moon and sun، solar radiation pressure، and so on. For this reason، it is constantly deviating from its original path and needs to study the effect of environmental disturbances on the orbital elements in order to properly correct the disturbed orbital parameters. To achieve the above goals، in this paper، we try to investigate the effect of the environmental perturbations on the orbital characteristics by simulating the satellite translational dynamic behavior in the presence of environmental disturbances. Then، utilizing the genetic algorithm and fuzzy logic approach، an attempt was made to modify the compensation logic of the orbital elements correction، so that، the satellite may be forced to remain in its limited operational orbital window during the mission lifetime. The proposed method could improve the problem-solving operational effectiveness to maintain the position of the satellite with the criterion of minimizing fuel consumption. The case study simulation results may indicate the capability of the proposed approach in satisfying the performance requirements of the satellite station-keeping maneuver
