An automatic system to weld multiple layers using Tungsten Arc (TIG) welding was in the process of being developed by Tool-Tec Welding Inc, prior to the company’s recent bankruptcy and subsequent closure. One of the project’s main concerns was the thermal expansion experienced by the part to be welded. To avoid having to install expensive sensors, it is necessary to predict the temperature and the dilatation of the mould during the welding process. The mould to be welded is preheated to prevent excessive stress due to extreme temperature differences in the material. As well, it is necessary to maintain the temperature of the mould during the welding process in order to avoid distortions or changes in size larger than 1 mm. Two models have been developed to predict the size of the preheat temperature of the mould and prevent mould size changes. One model uses the results of several simulations made with finite element analysis (FEA), while the other one takes advantage of Tool-Tec expert knowledge using the Fuzzy Logic method. Validation of both theories was done at the University of Waterloo, as Tool-Tec had at that point closed down. For the experiment, an MIG (Metal Arc Welding) robot was used, together with a medium-sized mould and an infrared camera. Using an IR camera is preferable to using sensors because a camera gives the whole temperature of the mould while the sensors provide information only about some points, and these may not necessarily be representative ones. However, an IR camera can record hundreds of pictures in a single experiment and analyzing them one by one to sort the useful from the useless is tedious work. Therefore, an automatic selection of the useful pictures and recognition of the mould was the best way to review the data. In the end, successful results were obtained since it was possible to maintain the preheat temperature of the mould within the required limits in order to avoid changes in size larger than 0.05mm. Nevertheless, future tests should involve larger and smaller moulds in order to tune the models presented in this thesis.

Thesis (PhDApSc(MineralsandMaterials)--University of South Australia, 2004.

Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Charalabos Doumanidis. Submitted to the Dept. of Mechanical Engineering. Includes bibliographical references (leaves 118-124). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 4, 2008) Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xix, 151 p.; also includes graphics Includes bibliographical references (p. 144-151). Available online via OhioLINK's ETD Center

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Terry R. McNelley. Includes bibliographical references (p. 149-152). Also available online.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 133-139).

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 115-120). Also available in electronic format on the Internet.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2006. / Includes bibliographical references (p. 27-29).

Made available in DSpace on 2014-06-11T19:27:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-17Bitstream added on 2014-06-13T20:35:19Z : No. of bitstreams: 1 gerlinneto_v_me_ilha.pdf: 3316220 bytes, checksum: 38f2eed06082bc165fba03b0915e908a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O transporte ferroviário é um meio de transporte já consolidado na maior parte do mundo desde o início do século XIX. Atualmente o Brasil está reiniciando a construção de novas ferrovias e novos investimentos na área surgiram. Com vista nestas novas ferrovias, estudos sobre a caracterização mecânica e de mecânica da fratura dos trilhos se faz necessária e o estudo da tenacidade do material dos trilhos é um importante fator no conhecimento das propriedades dos trilhos. As ferrovias são construídas em linhas contínuas soldadas por um processo denominado caldeamento. Este trabalho teve como objetivo estudar a influência da junta soldada no comportamento à fratura do material de trilhos ferroviários do tipo TR-57. Por meio de ensaios de tração, fadiga por flexão rotativa, impacto Charpy instrumentado e de tenacidade à fratura foi feita a caracterização do material e análise das influências da junta soldada nas características de tenacidade à fratura dinâmica aparente e de tenacidade à fratura do material dos trilhos. Os resultados mostraram que o material dos trilhos segue uma tendência de queda da tenacidade a fratura na região da junta soldada, além de mostrar que o volume de material ensaiado tem uma grande importância na escolha dos ensaios a serem realizados para a caracterização / Rail transportation is an already worldwide consolidated means of transportation since the beginning of 19th century. Nowadays Brazil is restarting to build new railways and investments for the area are appeared. With this new railways, studies on the mechanical and fracture mechanics characteristics of rails are needed and the rail’s material toughness is an important factor on knowing rails properties. Railways are built in continuous welded lines by a welding process called flash-butt welding. This work has as objective to study the welded joint influence on the fracture toughness of the brazilian TR-57 rails material. Using traction, rotate bending fatigue, instrumented Charpy impact and fracture toughness tests the material characterization and the welded joint influence on the apparent dynamical fracture toughness and fracture toughness of the rail’s material. The results showed that the rail’s material followed a fall tendency of the fracture toughness inside the welded joint, and also showed that the tested material volume has a major influence on choosing the tests to be used for characterization