Thesis (M. Eng.)--Carleton University, 2004. / Includes bibliographical references (p. 177-183). Also available in electronic format on the Internet.

Este trabalho analisou as diferenças entre o processo de conformação de rebites de Alumínio da liga AA 5052 e de aço inoxidável das ligas ABNT 420, ABNT 430 e ABNT 302, os quais são utilizados em grande escala na indústria cuteleira. Levando em conta as particularidades de cada material em estudo, foram analisadas as forças de conformação, tensões, deformações e temperaturas. A partir delas buscou-se chegar a um modelo de processo viável para se obter rebites de Aço inoxidável. Apesar da fabricação do rebite de Alumínio ser menos crítica, no que diz respeito a força necessária para conformação, a qualidade do produto é inferior, quando se compara com o Aço inoxidável. Este confere maior resistência mecânica e resistência à corrosão. Para modelamento do processo desenvolvido com o Alumínio AA5052 e com as ligas de Aço inoxidável utilizadas utilizou-se o software de simulação por elementos finitos SIMUFACT 11.0. Os resultados das simulações com o aço inoxidável com temperaturas a morno demonstraram grande dependência da temperatura para obtenção de tensões e forças suportadas pelo ferramental. Alguns resultados alcançados com o aço inoxidável aquecido, quando se variaram as temperaturas de 25ºC até 500ºC, geraram o grau de tensões e esforços no ferramental menor ou igual à condição onde o Alumínio é conformado a frio. Também, critérios como resistência à corrosão foram determinantes para a aprovação das ligas de aço inoxidável 302 e 430 estudadas. Esse resultado confirmou o que é indicado na bibliografia, onde são recomendadas ligas austeníticas e ferríticas, ao invés de martensíticas, para a fabricação de produtos de aço inoxidável que exigem alta resistência à corrosão, como é o caso dos rebites. / This study analyzed the differences between the rivet manufacturing process made by Aluminum of alloy AA5052 and Stainless Steel of alloys AISI 420, AISI 430 and AISI 302, wich are widely used in the cutlery industry. Taking into account the particularities of both materials, it was analyzed forming forces, stresses, strains and temperatures in order to find a viable process to manufacture stainless steel rivets. Even the manufacturing of Aluminum rivets is less critical, regarding the forming forces, the quality of the product is inferior than the stainless steel, wich provides more mechanical and corrosion resistance. The study of the process of forming Aluminum AA5052 and Stainless Steel rivets was developed using the finite elements software SIMUFACT 11.0. The simulation results of the Stainless Steel with warm temperatures showed big influence of the temperature to obtain lower stresses and forces, wich are supported by the tools. Some results with heated Stainless steel, considering temperatures from 25ºC to 500ºC, resulted in lower stress and tool forces than in the Aluminum with cold temperatures. Also, criteria like corrosion resistance was very important to the approval of the Stainless Steel AISI 302 and AISI 430. Those results confirm the information available in the bibliography, where it is preferential austenitic and ferritic alloys of stainless steel instead of martensitic alloys, when used to manufacture stainless steel rivets, wich require high corrosion resistance.

Este trabalho analisou as diferenças entre o processo de conformação de rebites de Alumínio da liga AA 5052 e de aço inoxidável das ligas ABNT 420, ABNT 430 e ABNT 302, os quais são utilizados em grande escala na indústria cuteleira. Levando em conta as particularidades de cada material em estudo, foram analisadas as forças de conformação, tensões, deformações e temperaturas. A partir delas buscou-se chegar a um modelo de processo viável para se obter rebites de Aço inoxidável. Apesar da fabricação do rebite de Alumínio ser menos crítica, no que diz respeito a força necessária para conformação, a qualidade do produto é inferior, quando se compara com o Aço inoxidável. Este confere maior resistência mecânica e resistência à corrosão. Para modelamento do processo desenvolvido com o Alumínio AA5052 e com as ligas de Aço inoxidável utilizadas utilizou-se o software de simulação por elementos finitos SIMUFACT 11.0. Os resultados das simulações com o aço inoxidável com temperaturas a morno demonstraram grande dependência da temperatura para obtenção de tensões e forças suportadas pelo ferramental. Alguns resultados alcançados com o aço inoxidável aquecido, quando se variaram as temperaturas de 25ºC até 500ºC, geraram o grau de tensões e esforços no ferramental menor ou igual à condição onde o Alumínio é conformado a frio. Também, critérios como resistência à corrosão foram determinantes para a aprovação das ligas de aço inoxidável 302 e 430 estudadas. Esse resultado confirmou o que é indicado na bibliografia, onde são recomendadas ligas austeníticas e ferríticas, ao invés de martensíticas, para a fabricação de produtos de aço inoxidável que exigem alta resistência à corrosão, como é o caso dos rebites. / This study analyzed the differences between the rivet manufacturing process made by Aluminum of alloy AA5052 and Stainless Steel of alloys AISI 420, AISI 430 and AISI 302, wich are widely used in the cutlery industry. Taking into account the particularities of both materials, it was analyzed forming forces, stresses, strains and temperatures in order to find a viable process to manufacture stainless steel rivets. Even the manufacturing of Aluminum rivets is less critical, regarding the forming forces, the quality of the product is inferior than the stainless steel, wich provides more mechanical and corrosion resistance. The study of the process of forming Aluminum AA5052 and Stainless Steel rivets was developed using the finite elements software SIMUFACT 11.0. The simulation results of the Stainless Steel with warm temperatures showed big influence of the temperature to obtain lower stresses and forces, wich are supported by the tools. Some results with heated Stainless steel, considering temperatures from 25ºC to 500ºC, resulted in lower stress and tool forces than in the Aluminum with cold temperatures. Also, criteria like corrosion resistance was very important to the approval of the Stainless Steel AISI 302 and AISI 430. Those results confirm the information available in the bibliography, where it is preferential austenitic and ferritic alloys of stainless steel instead of martensitic alloys, when used to manufacture stainless steel rivets, wich require high corrosion resistance.

No description available.

Les charpentes en bois doivent inévitablement inclure des assemblages pouvant transférer les charges entre les éléments de façon adéquate pour assurer l’intégrité de la structure. Les assemblages sont une partie critique des structures en bois puisque dans la plupart des cas, ce sont ceux-ci qui permettent de dissiper l’énergie et d’obtenir un mode de rupture ductile sous les charges sismiques. Ce mode de rupture est préférable, puisqu’il donne lieu à une grande déformation avant effondrement, permettant ainsi une évacuation des occupants en toute sécurité lors de tremblement de terre. Les assemblages à petits diamètres tels que les clous, les rivets et les vis sont fréquemment utilisés dans les constructions en bois et on suppose qu’ils amènent une rupture ductile bien qu’il soit impossible pour les concepteurs de prédire exactement le mode de rupture à l’aide de la méthode de calcul actuelle. De plus, les rivets ont une application très limitée dû au fait que la méthode de calcul utilisée actuellement s’applique à des configurations, essences et types de produits de bois très spécifiques. L’objectif de ce projet est d’évaluer une nouvelle méthode de calcul proposée par des chercheurs de Nouvelle-Zélande, Zarnani et Quenneville, pour les assemblages à rivets, mais adaptable pour les assemblages de bois à attaches de petits diamètres. Elle permet au concepteur de déterminer avec précision le mode de rupture des assemblages de différentes configurations avec différents produits de bois. Plus de 70 essais sur les assemblages à rivets et à clous résistants à des charges variant de 40kN à 800kN ont été effectués dans le cadre de ce projet de recherche afin de valider l’utilisation de cette méthode avec le produit du bois lamellé-collé canadien Nordic Lam et la comparer avec celle présentement utilisée au Canada. Les modes de rupture ductile, fragile et mixte ont été prévus avec l’emphase sur le mode fragile puisque c’est celui-ci qui est le plus variable et le moins étudié. Les assemblages en bois lamellé-collé Nordic Lam étaient cloués ou rivetés selon différentes configurations variant de 18 à 128 clous ou rivets. Les résultats démontrent une bonne prédiction de la résistance et des modes de rupture des assemblages à clous et à rivets. Pour quelques configurations des assemblages à rivets, les prédictions de la nouvelle méthode sont plus élevées qu’avec la méthode actuelle. Les assemblages à clous ont démontré des ruptures de la tige de clous au niveau du plan de cisaillement lors de tous les essais effectués, ce qui ne correspond pas à un mode ductile ou fragile prévue par la méthode de calcul. / Connections in wood structures must be able to transfer the load between the elements to ensure the structure integrity. Connections are critical in wood structures because under seismic load, they are used to ensure a ductile failure of the entire structure. This failure mode is preferable because it allows to dissipate the energy by developing large deformation, so that safe evacuation of occupants before the building collapse is possible. Small diameter fasteners like nails, screws and rivets are used a lot in wood structures under the assumption that they lead to a ductile failure although the calculations made with the current design method does not allow the designer to be sure of that. Furthermore, rivets have a very limited application because the current design method only applies to very specific configurations and wood species products. The objective of this project is to evaluate a new calculation method proposed by Zarnani and Quenneville from New-Zealand for connections with rivets, which can be extended to other small diameter fasteners in timber connections. It is not limited to specific configurations or wood products and it allows the designer to predict the failure mode. Over 70 tests on riveted and nailed connections with resistances varying from 40kN to 800kN were conducted during this project in order to validate the application of this method using a Canadian-made glulam timber. The new method was compared with design methods currently used in Canada. Ductile, mixed and brittle failure modes were targeted with the emphasis on brittle failure because it has the highest variability and it is the least studied.Wood connections were made of Nordic Lam glulam using rivets or nails with configurations varying from 18 to 128 fasteners. The results show good predictions of the connection resistance and the failure modes of connections with nails and rivets. For some configurations of rivets connections, the predictions of the new method are higher than predictions using the current design method. The nails connections showed rupture of the nails shank near the shear plane in all tests, which does not correspond to ductile or brittle failure modes predicted by the model.

No description available.

A study was conducted to investigate simple, cost-effective manufacturing techniques to delay skin-core delamination, micro-buckling and bearing stress failures resulting from fastener-hole interactions. Composite sandwich panels, with and without damage arrestment devices (DADs), were subjected to monotonic compression at a rate of 5mm per second, and compression-compression fatigue at 50% yield at an amplitude of 65%, under temperatures of 75, 100, 125, 150, 175, and 200 °F. The sandwiches tested were composed of two-layer cross-weave carbon fiber facesheets, a polyurethane foam core, and an epoxy film adhesive to join the two materials. The most successful method to delay the aforementioned failures involved milling rectangular slots in the foam core perpendicular to the holes and adding three additional layers of carbon fiber cross-weave. For the monotonic cases, the ultimate load increases were 97, 87, 100, 131, 96, and 119% for each of the respective temperatures listed above with a negligible weight increase. For the fatigue cases, the number of cycles for each test case was nearly identical. This still represents a large improvement because the yield used in the loading condition for the specimens with DADs was 97% greater than the specimens without DADs. The experimental results were compared with a finite element model (FEM) built in Abaqus/CAE. The numeric and experimental results showed a strong correlation. All test specimens were manufactured and tested in the California Polytechnic State University Aerospace/Composites Laboratory.