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Tesi etd-09252007-083030


Thesis type
Tesi di laurea vecchio ordinamento
Author
BAGNOLI, LUCA
URN
etd-09252007-083030
Title
Multibody analysis of solar array deployment using flexible bodies
Struttura
INGEGNERIA
Corso di studi
INGEGNERIA AEROSPAZIALE
Commissione
Relatore Mengali, Giovanni
Relatore Salvetti, Attilio
Parole chiave
  • solar panel
  • solar array
  • ADAMS
  • deployment
  • Multibody
Data inizio appello
17/10/2007;
Consultabilità
completa
Riassunto analitico
The solar panels represent the main device for collecting and converting solar energy into<br>electrical energy and they are widely used in space missions supplying the energy<br>necessary for both spacecrafts and payloads. To optimize the sun exposed surface the<br>panels are usually organized in wings configurations, that, stored during the launch,<br>deploy in the space at the beginning of the operative phase of the satellite.<br>This work of thesis focus on this deployment phase and on the associated dynamic<br>loads. The need of this investigation is connected to the strict requirements on the<br>deployment. Since we want to be sure of the complete deployment in every condition<br>with high margin of safety, the energy stored in the deployment mechanism is quite<br>oversized. This leads to the dynamic loads that we want to estimate.<br>The key topic of the thesis consists in the generation of a flexible multi-body model for<br>solar arrays deployment studies and analysis. The main aim of this model is the<br>verification and validation of a usually pre-existing rigid model used for the conceptual<br>studies of the deployment.<br>In this rigid model, generated directly in ADAMS environment, all the structural<br>stiffness is condensed in a small number of DOF (rotational springs located on the hinge<br>lines). It’s clear that this way of modelling does not cover higher frequency or side<br>dynamics effects. By the introduction of a flexible model we want to investigate these<br>effects and check the right working of the mechanism also in presence of deformation.<br>Optionally, using the flexible model, we can also have a first estimation of stresses and<br>strains due to the dynamics of the deployment.<br>The two main requirements for a flexible model are to be easy to generate and to be<br>compatible with the related rigid model. These two aspects are important to avoid<br>significant impact on the project budget. The flexible bodies are generated using the<br>user friendly interface of PATRAN (avoiding or minimizing manual inputs in<br>NASTRAN) and then importing this flexible bodies in an ADAMS adapted rigid model<br>(avoiding to re-built the flexible model from the beginning).<br>The first chapter of the thesis will show the theoretical background of the NASTRANADAMS<br>interface for the generation of flexible bodies. This theoretical part, even if not<br>strictly necessary for the final-user, is anyway important for the full comprehension of<br>some of the choices that will be adopted.<br>The second chapter will introduce and explain the main characteristics of a solar array<br>rigid model using BEPI COLOMBO MPO solar array and AMOS 3 solar array as<br>examples. The third chapter will focus on the generation of the flexible model using the<br>same two formers examples.<br>In chapter four the results of the two models will be compared and in the fifth chapter<br>the consequent conclusions will be drawn. In last chapter six will be shown other<br>possible fields of application of the flexible body modelling with ADAMS.
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