Abstract
The use of computer models to predict the behavior of the Space Vehicles is used to understand the natural frequencies and dynamic system responses of a complex flexible multi body system such as the International Space Station (ISS). One of the major problems in assembling the ISS is simulating dynamics and control analysis in orbit. If dynamic analysis is not tested on earth, the ISS could run into malfunction problems. This problem is a challenge that confronts the ISS program because these major components have to fit together in significantly small tolerances the first time when they are attached in orbit. NASA members can't physically run any test in orbit instead they use computer simulation for analysis purposes that will predict dynamics behavior of ISS in space. Each new mission of the Space Shuttle is designed to build the ISS and each new mission presents new challenges that need to be confronted during flight. A complete physical system is designed as a model on a computer to understand the modes of vibration and to design a control system capable of controlling the proposed maneuvers. Once the computer model is designed according with the actual station, tests are conducted with data from real flights for modal analysis, guidance and control of flight and Orbiter Repair Maneuvers. This thesis proposes a new method for producing a new generation of computer models while still preserving significant dynamics information . Through the use of 3D simulation, NASA are able to learn valuable information to fix problems related to the guidance and control of ISS. One of those is the emergency plan for inspection , repair of the shuttle known as Orbiter Repair Maneuvers. These computer models are generated from using solid modeling techniques, such models are transformed into time dependent dynamics finite element models. Such process and results are presented here using a technique that mixes solid modeling and dynamic finite element modeling. Software packages such as Solidworks, MSC visua1Nastran4D, MATLAB and Simulink have been incorporated in the process. The computer model results will provide NASA engineers with new alternative methods to study forces, deflections, vibrations , and position control which can lead to the discovery of new methods ..that were not even envisioned before.