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Publication
Projeto de veĆculo lunar
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| 13.06 MB | Adobe PDF |
Authors
Abstract(s)
Esta secĆ§Ć£o descreve o trabalho desenvolvido relativamente ao projeto do protĆ³tipo de veĆculo lunar. Primeiro, efetuaram-se as pesquisas relativamente aos veĆculos existentes e as suas caracterĆsticas. Depois, efetuou-se a pesquisa sobre as condiƧƵes na Lua, a evoluĆ§Ć£o da roda e as baterias para aplicaĆ§Ć£o espacial. Posteriormente, efetuou-se a modelaĆ§Ć£o 3D e 2D do protĆ³tipo de veĆculo lunar com o auxĆlio do software Solidworks, tendo-se obtido duas soluƧƵes, uma para missĆ£o tripulada e outro para missĆ£o nĆ£o tripulada. O veĆculo selecionado, foi projetado com um braƧo robĆ³tico para coletar amostras lunares atravĆ©s de um balde frontal ou nivelar o solo lunar com o auxĆlio de uma lĆ¢mina frontal. Consideraram-se como requisitos estruturais de projeto para o cĆ”lculo estrutural analĆtico a verificaĆ§Ć£o Ć cedĆŖncia dos pinos e dos apoios do chassis, a resistĆŖncia Ć fadiga dos parafusos (que suportam cada motor da roda) para uma carga cĆclica, a resistĆŖncia ao corte e ao esmagamento da chaveta de ligaĆ§Ć£o do veio do motor, o cĆ”lculo da forƧa mĆnima necessĆ”ria para o deslocamento mĆ”ximo admitido da mola e a anĆ”lise do sistema de suspensĆ£o para a situaĆ§Ć£o mais desfavorĆ”vel, a qual corresponde o impacto de uma roda numa rocha.
Efetuou-se o diagrama de corpo livre do chassis, do pino e do sistema de suspensĆ£o. Calcularam-se as reaƧƵes nos pinos e nos apoios do chassis (geradas pelo peso e pela forƧa de impacto da rocha sobre uma roda) e compararam-se as tensƵes equivalentes resultantes com a tensĆ£o de cedĆŖncia dos respetivos materiais. A tensĆ£o equivalente foi inferior Ć tensĆ£o de cedĆŖncia do material respetivo, logo, o domĆnio de deformaĆ§Ć£o em causa foi o elĆ”stico. Portanto, nĆ£o se espera falhas em serviƧo. O projeto do veĆculo lunar considerou metodologias analĆticas e numĆ©ricas no cĆ”lculo estrutural, bem como a elaboraĆ§Ć£o de desenhos tĆ©cnicos do veĆculo desenvolvido.
Abstract This section describes the developed work in relation to the project of the lunar rover prototype. First, it was done the research of existing rovers and their characteristics. Then, the research of the conditions on the Moon, the evolution of the wheel and batteries for space applications. Subsequently, 3D and 2D modelling of the lunar rover prototype was done using Solidworks software, resulting in two solutions, one for a manned mission and the other for an unmanned mission. The selected rover was designed with a robotic arm to collect lunar samples using a front bucket or to level the lunar soil using a front blade. The structural design requirements for the analytical structural calculation were the verification of the yielding of the pins and chassis supports, the fatigue resistance of the bolts (which support each wheel motor) for a cyclic load, the shear and crushing resistance of the motor shaft connecting key, the calculation of the minimum force required for the maximum permitted spring displacement and the analysis of the suspension system for the most unfavorable situation, which corresponds to the impact of a wheel on a rock. The free-body diagram of the chassis, pin and suspension system was produced. The reactions on the pins and chassis supports (generated by the weight and impact force of the rock on a wheel) were calculated and the resulting equivalent stresses were compared with the yield stress of the respective materials. The equivalent stress was lower than the yield stress of the respective material, therefore, the deformation domain in question was elastic. Therefore, failures in service are not expected. The design of the lunar vehicle considered analytical and numerical methodologies in the structural calculation, as well as the preparation of technical drawings of the developed vehicle.
Abstract This section describes the developed work in relation to the project of the lunar rover prototype. First, it was done the research of existing rovers and their characteristics. Then, the research of the conditions on the Moon, the evolution of the wheel and batteries for space applications. Subsequently, 3D and 2D modelling of the lunar rover prototype was done using Solidworks software, resulting in two solutions, one for a manned mission and the other for an unmanned mission. The selected rover was designed with a robotic arm to collect lunar samples using a front bucket or to level the lunar soil using a front blade. The structural design requirements for the analytical structural calculation were the verification of the yielding of the pins and chassis supports, the fatigue resistance of the bolts (which support each wheel motor) for a cyclic load, the shear and crushing resistance of the motor shaft connecting key, the calculation of the minimum force required for the maximum permitted spring displacement and the analysis of the suspension system for the most unfavorable situation, which corresponds to the impact of a wheel on a rock. The free-body diagram of the chassis, pin and suspension system was produced. The reactions on the pins and chassis supports (generated by the weight and impact force of the rock on a wheel) were calculated and the resulting equivalent stresses were compared with the yield stress of the respective materials. The equivalent stress was lower than the yield stress of the respective material, therefore, the deformation domain in question was elastic. Therefore, failures in service are not expected. The design of the lunar vehicle considered analytical and numerical methodologies in the structural calculation, as well as the preparation of technical drawings of the developed vehicle.
Description
Trabalho de Projeto para obtenĆ§Ć£o do grau de Mestre em Engenharia MecĆ¢nica, na Ćrea de EspecializaĆ§Ć£o de ManutenĆ§Ć£o e ProduĆ§Ć£o
Keywords
VeĆculo lunar SimulaĆ§Ć£o CAD Impacto Lunar rover Simulation Impac