investigating space radiation
Majid Mokhtari; Hamideh Daneshvar; Morteza Bahmani nejad; Shahryar Malekie; Armin Mosayebi,; Amir Torabpoor-Isfahani,; Iman Aryanian
Volume 15, Issue 2 , June 2022, , Pages 59-69
Abstract
Sandwich panels are used in various industries due to their high special strength. It is used in ultra-light aerospace structures. In this paper the protective effect of sandwich structures used in ultralight space structures against gamma rays is investigated. Eight structures of the most widely used ...
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Sandwich panels are used in various industries due to their high special strength. It is used in ultra-light aerospace structures. In this paper the protective effect of sandwich structures used in ultralight space structures against gamma rays is investigated. Eight structures of the most widely used structures used in space structures such as telecommunication antennas and satellite bodies are exposed to radioisotopic sources of gamma rays (Amercium barium and cesium) with energies of 60 kV, 80 kV, 382 and 66 kV, have been compared to each other. Surface material (aluminum and carbon), surface thicknesses and honeycomb cell dimensions are the most important evaluation parameters. In this paper, different structures have been compared using the "special protection" parameter and the best structure from a protection perspective has been identified and reported.
A. Vafaeesefat; S. H. Tabatabai
Volume 2, Issue 3 , December 2009, , Pages 43-50
Abstract
Weight optimization is one of important parameters in space structure design. Size optimization is usually performed using gradient or genetic algorithm. Gradient algorithm is based on derivation of objective function and constraints of problem. The performance of gradient method is depended on start ...
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Weight optimization is one of important parameters in space structure design. Size optimization is usually performed using gradient or genetic algorithm. Gradient algorithm is based on derivation of objective function and constraints of problem. The performance of gradient method is depended on start point and do not search all design domain. Genetic algorithm searches all design domains, but it cannot get close to the global optimum. In this paper, a new method is presented for size optimization. The algorithm starts with genetic algorithm and result of genetic algorithm is then used as start point for gradient algorithm. The presented method is used for size optimization of two trusses with three and ten elements. It is also applied on for optimization of a lattice structure of parabolic antenna. The results show that the present algorithm can perform better results compared to genetic algorithm alone.
