erfan beygi; Amirhossain Adami
Volume 11, Issue 4 , December 2018, , Pages 43-50
Abstract
Basically, it takes alot of time to analyze structures with different parameters, depending on the type of structure and parameters. Also, by changing any parameter, all the analysis process must be repeated. Therefore analyze the effect of different parameters on the behavior of structures, many analyzes ...
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Basically, it takes alot of time to analyze structures with different parameters, depending on the type of structure and parameters. Also, by changing any parameter, all the analysis process must be repeated. Therefore analyze the effect of different parameters on the behavior of structures, many analyzes should be carried out that are time consuming. The results obtained are valid only for the same parameters, and are not valid by changing the parameters. In this research, a Nested dependence method has been developed that can be used to determine the behavior of the structure with proper accuracy with short time. In this method, first an interval is considered for different parameters of the structure. Then, by using the finite element analysis method and applying the loading and boundary conditions, the behavior of the structure. By repeating this process to extract the appropriate number of input data, a Nested dependence method can be used to estimate the structure behavior of different inputs.
M. M. Shokrieh; M. Fakoor; Z. Daneshjoo
Volume 6, Issue 4 , January 2014, , Pages 13-22
Abstract
Solar panels are used in satellites to absorb solar energy and supply the power needed for space missions. Mission definition and satellite lifetime is restricted by the way and the amount of energy that can be supplied for satellite subsystems. Therefore, the design of satellite solar panels as a unique ...
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Solar panels are used in satellites to absorb solar energy and supply the power needed for space missions. Mission definition and satellite lifetime is restricted by the way and the amount of energy that can be supplied for satellite subsystems. Therefore, the design of satellite solar panels as a unique source for power supply in satellites is very sensitive and important. In this paper, an efficient design for solar panels of a GEO communication satellite is proposed considering the maximum strength to weight ratio and minimum deflection. For this purpose different space structures including Iso Grid structures, honeycomb and composite plates are studied. Several structural analyses are performed on the models in order to assurance from the strength and durability of the model in space working environments. The design according to composite-honeycomb is introduced as the best model for solar panel structure. The proper configuration of layers is also presented by developing a code based on an optimization algorithm.
Y. Ghaderi-Dehkordi
Volume 2, Issue 3 , December 2009, , Pages 27-34
Abstract
Corrugated tunnel is a pipe, which its outer surface is corrugated and is generally used for fluid transfer in different industries. Owing to complicated geometrical structure of corrugated tunnels, very limited numbers of closed-form equations have been presented for analysis of their mechanical behavior. ...
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Corrugated tunnel is a pipe, which its outer surface is corrugated and is generally used for fluid transfer in different industries. Owing to complicated geometrical structure of corrugated tunnels, very limited numbers of closed-form equations have been presented for analysis of their mechanical behavior. In the present study, a mathematical model is proposed for strength and buckling analysis of corrugated pipes. In addition, an algorithm is presented for designing of corrugated tunnels. In order to verify the presented model, its results were compared with those obtained by finite element method (the ABAQUS software was used) and a good agreement was observed. Finally, some corrugated tunnels were designed, fabricated and tested for a special industrial application. Critical pressure values obtained from the tests were less than those calculated from the theoretical method, which could be due to fabricated flaws.
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.
