Low-cost microsatellites structures represent an extremely interesting challenge and a excellent technology workbench. The contrast between the need of limited weights imposed by launch costs on a hand and the need of a safe satellite structure capable to protect devices and payloads during launch on the other, induces researchers to evaluate a wide range of alternative solution from traditional technologies and material to advanced structures and concepts. The goal is to achieve the best compromise between weight, performances and costs. In this paper will be presented the goals and results of the improvement process which involved the structure of ALMASat-1, the first microsatellite of the University of Bologna. As example the upper plate of the modular structure had been improved. Starting from the analysis of the component, originally realized from a machined aluminum plate, it has been possible to define critical parameters as reference for performance comparison between different technologies and materials. The first frequency of the modal analysis, as well as the overall shape of the plate, have been taken as fixed parameters. Once defined the new materials and technologies, carbon fiber lamination in this case, it has been possible to determine the total plate thickness, number of layers and their orientation thanks to an iterative analysis procedure. A specific ANSYS code had been developed to modify dynamically the thickness of the plate and execute a series of modal analysis until the first natural frequency calculated was equal to the reference parameter previously set. In order to verify the dynamic behavior of the plate in launch environment a further Power Spectral Density analysis has been performed evaluating the statistical results in terms of displacements, accelerations, global and layer stresses and frequency response by using advanced post-processing techniques. As result a new carbon fiber upper plate will be produced and tested in order to correlate numerical and experimental results and confirm the technology improvement success.
Improvements in Materials Technologies for Low-cost Microsatellites Structures: from Aluminum to Carbon Fiber
TROIANI, ENRICO
2008
Abstract
Low-cost microsatellites structures represent an extremely interesting challenge and a excellent technology workbench. The contrast between the need of limited weights imposed by launch costs on a hand and the need of a safe satellite structure capable to protect devices and payloads during launch on the other, induces researchers to evaluate a wide range of alternative solution from traditional technologies and material to advanced structures and concepts. The goal is to achieve the best compromise between weight, performances and costs. In this paper will be presented the goals and results of the improvement process which involved the structure of ALMASat-1, the first microsatellite of the University of Bologna. As example the upper plate of the modular structure had been improved. Starting from the analysis of the component, originally realized from a machined aluminum plate, it has been possible to define critical parameters as reference for performance comparison between different technologies and materials. The first frequency of the modal analysis, as well as the overall shape of the plate, have been taken as fixed parameters. Once defined the new materials and technologies, carbon fiber lamination in this case, it has been possible to determine the total plate thickness, number of layers and their orientation thanks to an iterative analysis procedure. A specific ANSYS code had been developed to modify dynamically the thickness of the plate and execute a series of modal analysis until the first natural frequency calculated was equal to the reference parameter previously set. In order to verify the dynamic behavior of the plate in launch environment a further Power Spectral Density analysis has been performed evaluating the statistical results in terms of displacements, accelerations, global and layer stresses and frequency response by using advanced post-processing techniques. As result a new carbon fiber upper plate will be produced and tested in order to correlate numerical and experimental results and confirm the technology improvement success.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
