Con base en el estudio del sector armamentístico, podemos definir la gestión de mantenimiento como uno de los problemas más relevantes dentro de su cadena de producción. La deficiente planificación y los errores en las entregas de pedidos a tiempo afectan en gran medida la eficacia de la empresa y su retorno de inversión. Por tal motivo, surge la necesidad de encontrar soluciones que permitan el crecimiento del sector armamentístico peruano y metalmecánico. La presente investigación propone una solución basada en las herramientas TPM y Spare Parts Management que permitirán una buena gestión del flujo de actividades de mantenimiento preventivo o correctivo, gestionar eficientemente el movimiento de los repuestos y su respectiva ubicación e inventarios en el proceso de ingreso de nuevos repuestos, eliminar los desperdicios innecesarios y controlar de manera óptima los repuestos de las máquinas. La empresa en estudio es una empresa con régimen estatal, pero con dirección privada, la cual presenta problemas en su gestión de mantenimiento, debido al exceso de paradas inesperadas y atascos, alta producción de productos no conformes y baja eficacia de producción de municiones a tiempo. Esta propuesta logró incrementar la eficacia de la producción de casquillos y balas en un 6.99% pasando de un 66.52% a 73.51%. / Based on the study of the arms sector, we can define maintenance management as one of the most relevant problems within its production chain. Poor planning and errors in order delivery on time greatly affect the efficiency of the company and its return on investment. For this reason, the need arises to find solutions that allow the growth of the Peruvian arms and metalworking sector. The present investigation proposes a solution based on the TPM and Spare Parts Management tools that will allow a good management of the flow of preventive or corrective maintenance activities, efficiently manage the movement of spare parts and their respective location and inventories in the process of entering new spare parts, eliminate unnecessary waste and optimally control machine spare parts. The company under study is a company with a state regime, but with private management, which presents problems in its maintenance management, due to the excess of unexpected stops and jams, high production of non-conforming products and low efficiency of ammunition production on time. . This proposal managed to increase the efficiency of the production of casings and bullets by 6.99%, going from 66.52% to 73.51%. / Trabajo de Suficiencia Profesional

[pt] A determinação do limiar de propagação de trincas de fadiga oferece uma gama de utilização dos materiais na engenharia, na aplicação a projetos que sejam tolerantes ao dano. [delta]Kth é uma ferramenta que permite o estabelecimento de um critério de carregamento sob o qual as trincas não crescerão significativamente durante as operações de serviço do componente. Para sua determinação ser amplamente aplicada, foi necessário estabelecer e estudar os fatores que pudessem influenciá-lo positiva ou negativamente. Dentre os quais, a microestrutura apresentou grande importância porque precisou ser controlada desde a fabricação do material até a colocação em serviço do componente acabado. A finalidade do componente e os esforços a que são submetidos quando em serviço determinam a seleção do material. Assim, enumerou-se características básicas e requisitos mínimos que atenderam a segurança e reduziram a relação custo-benefício. Foram selecionados materiais (SAE 4340 e SAE 4140) cuja composição química e propriedades mecânicas fossem semelhantes ao 42CrMo4 para que pudessem servir de alternativa no emprego de eixos-virabrequim a fim de propor uma solução no problema prático o qual estes vinham rompendo muito abaixo do limite de vida em fadiga a que se propunham. Os resultados obtidos se mostraram satisfatórios pois nos ensaios de propagação de trinca de um dos materiais escolhidos (SAE 4140) obteve-se [delta]Kth de 12,48 MPa[raiz quadrada]m e no material de referência, [delta]Kth (médio) de 6,1 MPa[raiz quadrada]m. A observação da microestrutura do material de referência pode, com ressalvas, ser visto como indicativo de corroboração do resultado apresentado no [delta]Kth, pois foram localizadas ocorrências de inclusões dispersas na matriz metálica. / [en] The determination of the fatigue crack propagation threshold offers a range of materials utilization in engineering, in application to projects that are tolerant to damage. [delta]Kth is a tool that allows the establishment of a loading criterion under which the cracks will not grow significantly during the service operations of the component. For its determination to be widely applied, it was necessary to establish and study the factors that could influence it positively or negatively. Among them, the microstructure was of great importance because it had to be controlled from the material manufacturing to the placing putting into service of a finished component. The aim of the component and the stresses to which it is subjected when in service determine the material selection. Thus, basic characteristics and minimum requirements were listed which have attend the safety and has reduced cost-benefit ratio. Materials (SAE 4340 and SAE 4140) were selected whose chemical composition and mechanical properties that were similar to DIN 42CrMo4 so that they could serve as an alternative in the use of crankshafts to propose a solution in the practical problem which they were breaking well below the limit fatigue life that they proposed. The results obtained were satisfactory because in the fracture toughness tests of one of the chosen materials (SAE 4140) [delta]Kth of 12.48 MPa[square root]m was obtained and in the reference material, [delta]Kth(average) of 6.1 MPa[square root]m. The observation of the microstructure of the reference material may indicate, with restrictions, as a corroboration of the result presented in the [delta]Kth, because occurrences of dispersed inclusions in the steel matrix.

No description available.

No description available.

This Bachelor's thesis explores the impact of a fast-forwarding mechanic on player experience within Liberty Land, an in-house developed casual farming game. The research question is: How do changes in the passage of time, facilitated by the time-altering mechanic in our developed game, Liberty Land, impact the player's experience? The authors researched the question through the creation of their game and then playtesting with two distinct groups. The authors used game-feel (Swink, 2009) and the MDA framework (Hunicke et al., 2004) to do the research.  Group A experienced the game with the time-accelerating mechanic, while Group B acted as the control group and did not have access to the mechanic. Players would then answer a survey that corresponded with which group they had. After the playtests, the authors reviewed the data and analyzed the results. Group A had the time-altering mechanic and did report finding it helpful in reducing waiting times. They believed it aided game progression, even though core balancing issues made some actively use the mechanic less than expected. The group found it enjoyable and easy to use, although some did express concerns about potential stress from optimizing time usage. The insights from Group B, who experienced the game without the time-altering mechanic, underscore the importance of game content and loop variations for immersion and engagement. The emotional responses from both groups analyzed through the MDA framework revealed notable themes of sensation, discovery, and submission. The study also identified challenges such as low survey participation rates, ongoing refinement in the game loop, and the state of the game. While there is evidence of a positive impact on the player’s experience, the heavy limitations and problems make the research largely inconclusive as a whole.

This dissertation is a contribution to the development of a unified model of continuum mechanics, describing both fluids and elastic solids as a general continua, with a simple material parameter choice being the distinction between inviscid or viscous fluid, or elastic solids or visco-elasto-plastic media. Additional physical effects such as surface tension, rate-dependent material failure and fatigue can be, and have been, included in the same formalism. The model extends a hyperelastic formulation of solid mechanics in Eulerian coordinates to fluid flows by means of stiff algebraic relaxation source terms. The governing equations are then solved by means of high order ADER Discontinuous Galerkin and Finite Volume schemes on fixed Cartesian meshes and on moving unstructured polygonal meshes with adaptive connectivity, the latter constructed and moved by means of a in- house Fortran library for the generation of high quality Delaunay and Voronoi meshes. Further, the thesis introduces a new family of exponential-type and semi- analytical time-integration methods for the stiff source terms governing friction and pressure relaxation in Baer-Nunziato compressible multiphase flows, as well as for relaxation in the unified model of continuum mechanics, associated with viscosity and plasticity, and heat conduction effects. Theoretical consideration about the model are also given, from the solution of weak hyperbolicity issues affecting some special cases of the governing equations, to the computation of accurate eigenvalue estimates, to the discussion of the geometrical structure of the equations and involution constraints of curl type, then enforced both via a GLM curl cleaning method, and by means of special involution-preserving discrete differential operators, implemented in a semi-implicit framework. Concerning applications to real-world problems, this thesis includes simulation ranging from low-Mach viscous two-phase flow, to shockwaves in compressible viscous flow on unstructured moving grids, to diffuse interface crack formation in solids.

O objetivo deste trabalho foi avaliar o efeito da soldagem TIG (\"tungsten inert gas\") e compará-la com soldagem a laser, em hastes cilíndricas e supra-estruturas implantosuportadas, confeccionadas em titânio comercialmente puro (Ti cp) por meio dos ensaios de resistência mecânica (tração e flexão) e desajuste marginal, respectivamente. Foram confeccionados noventa corpos-de-prova em titânio cp, sendo sessenta, na forma de hastes cilíndricas, obtidas por fundição de hastes de latão, e trinta na forma de supra-estruturas implanto-suportadas, obtidas por modelo de gesso com quatro análogos de implantes Microunit (Conexão), com dez repetições para cada grupo (controle, solda TIG, solda a Laser). Para a obtenção dos corpos-de-prova, foi realizada inclusão em revestimento Rematitan Plus, de acordo com as instruções fabricante. Os anéis foram submetidos aos ciclos térmicos e posicionados na máquina de fundição (Rematitan), sob arco voltaico, vácuo e atmosfera de argônio, com injeção de titânio sob vácuo-pressão. Após resfriamento, as fundições foram desincluídas e jateadas com óxido de alumínio. Os corpos-de-prova obtidos em forma de hastes cilíndricas foram distribuídos aleatoriamente, em três grupos, para ambos os ensaios, resistência à tração e flexão: grupo controle (sem solda), solda TIG e solda a Laser. As trinta supra-estruturas foram divididas aleatoriamente em três grupos: I- controle - monobloco; II-B- pós-soldagem TIG e III-B- pós-soldagem a Laser; os grupos II-A e III-A, foram constituídos dos espécimes antes do processo de soldagem: II-A- pré-soldagem TIG e III-A- pré-soldagem a Laser. Os dados obtidos para o Ensaio de Tração (MPa) foram analisados estatisticamente pelos testes ANOVA e Tukey (&alpha;= 0,05). O teste complementar de Tukey (p = 0,05) evidenciou que houve diferença entre o grupo controle (605,84 ± 19,83) e os métodos de soldagem TIG (514,90 ± 37,76) e Laser (515,85 ± 62,07). Para o Ensaio de Flexão (MPa), o teste não-paramétrico de Kruskal-Wallis mostrou que não houve diferença estatisticamente significante entre os processos de soldagem TIG (1559,66) e Laser (1621,64), contudo a diferença foi significante entre estes grupos e o controle (1908,75). Para análise dos resultados do desajuste marginal (&mu;m) das supra-estruturas implanto-suportadas, o teste nãoparamétrico de Kruskal-Wallis revelou que não houve diferença estatisticamente significante entre os grupos pós-soldagem TIG (250) e pós-soldagem Laser (241), entretanto, o grupo controle (770) apresentou o maior desajuste. Pelos resultados obtidos e dentro das limitações deste estudo, pode-se afirmar que a soldagem a TIG propicia a obtenção de resultados similares à soldagem a Laser. / The aim of this study was to evaluate the effect of TIG welding (tungsten inert gas) and compare it with Laser welding, of the cylindrical rods and implant-supported frameworks, obtained by in commercially pure titanium (cp) through the mechanical resistance (tensile and flexural strength) and misfit marginal, respectively. Ninety specimens have been fabricated titanium cp, and sixty, cylindrical rods, obtained by casting of the brass rods, and thirty implant-supported frameworks, obtained by plaster die with four similar - Microunit implants (Connection), with ten repetitions for each group (control, TIG welding, laser welding). The specimens were invested in Rematitan Plus, according to the manufacturer instructions. The rings were subjected to thermal cycling and positioned in the machine of casting (Rematitan) under voltaic arc, vacuum and atmosphere of argon, with injection of titanium vacuumpressure. After cooling, were manually and airbone-particle abraded with aluminum oxide. The specimes cylindrical rods were randomly distributed in three groups, for tests, tensile and flexural strength: the control group (without welding), TIG welding and soldering laser. The above thirty-structures were randomly divided into three groups: I- one-piece-cast (control)-, II-B-after-TIG welding and III-B-after-Laser welding, the Group II-A, III-A, consisted of specimens before the process of welding: II-A-before-TIG welding and III-A before-Laser welding. The results for the test Traction were submitted to variance analysis ANOVA (p < 0.05) being observed difference between groups. The supplementary Tukey test (p = 0.05) showed that there was a difference between the control group (605.84 ± 19.83) and the methods of welding TIG (514.90 ± 37.76) and laser (515.85 ± 62.07). To test the Flexion nonparametric test Kruskal-Wallis showed that there was no statistically significant difference between the processes of TIG welding (1559.66) and Laser (1621.64), but the difference was significant between these groups and control (1908.75). For analysis of the results of marginal misfit implant-supported frameworks, the non-parametric Kruskal-Wallis test revealed that there was no statistically significant difference between groups after-TIG welding (250) and after- Laser welding (241), however, the control group (770) showed the largest misfit. With these and the limitations of this study TIG welding in may be to Laser welding.

O objetivo deste trabalho foi avaliar o efeito da soldagem TIG (\"tungsten inert gas\") e compará-la com soldagem a laser, em hastes cilíndricas e supra-estruturas implantosuportadas, confeccionadas em titânio comercialmente puro (Ti cp) por meio dos ensaios de resistência mecânica (tração e flexão) e desajuste marginal, respectivamente. Foram confeccionados noventa corpos-de-prova em titânio cp, sendo sessenta, na forma de hastes cilíndricas, obtidas por fundição de hastes de latão, e trinta na forma de supra-estruturas implanto-suportadas, obtidas por modelo de gesso com quatro análogos de implantes Microunit (Conexão), com dez repetições para cada grupo (controle, solda TIG, solda a Laser). Para a obtenção dos corpos-de-prova, foi realizada inclusão em revestimento Rematitan Plus, de acordo com as instruções fabricante. Os anéis foram submetidos aos ciclos térmicos e posicionados na máquina de fundição (Rematitan), sob arco voltaico, vácuo e atmosfera de argônio, com injeção de titânio sob vácuo-pressão. Após resfriamento, as fundições foram desincluídas e jateadas com óxido de alumínio. Os corpos-de-prova obtidos em forma de hastes cilíndricas foram distribuídos aleatoriamente, em três grupos, para ambos os ensaios, resistência à tração e flexão: grupo controle (sem solda), solda TIG e solda a Laser. As trinta supra-estruturas foram divididas aleatoriamente em três grupos: I- controle - monobloco; II-B- pós-soldagem TIG e III-B- pós-soldagem a Laser; os grupos II-A e III-A, foram constituídos dos espécimes antes do processo de soldagem: II-A- pré-soldagem TIG e III-A- pré-soldagem a Laser. Os dados obtidos para o Ensaio de Tração (MPa) foram analisados estatisticamente pelos testes ANOVA e Tukey (&alpha;= 0,05). O teste complementar de Tukey (p = 0,05) evidenciou que houve diferença entre o grupo controle (605,84 ± 19,83) e os métodos de soldagem TIG (514,90 ± 37,76) e Laser (515,85 ± 62,07). Para o Ensaio de Flexão (MPa), o teste não-paramétrico de Kruskal-Wallis mostrou que não houve diferença estatisticamente significante entre os processos de soldagem TIG (1559,66) e Laser (1621,64), contudo a diferença foi significante entre estes grupos e o controle (1908,75). Para análise dos resultados do desajuste marginal (&mu;m) das supra-estruturas implanto-suportadas, o teste nãoparamétrico de Kruskal-Wallis revelou que não houve diferença estatisticamente significante entre os grupos pós-soldagem TIG (250) e pós-soldagem Laser (241), entretanto, o grupo controle (770) apresentou o maior desajuste. Pelos resultados obtidos e dentro das limitações deste estudo, pode-se afirmar que a soldagem a TIG propicia a obtenção de resultados similares à soldagem a Laser. / The aim of this study was to evaluate the effect of TIG welding (tungsten inert gas) and compare it with Laser welding, of the cylindrical rods and implant-supported frameworks, obtained by in commercially pure titanium (cp) through the mechanical resistance (tensile and flexural strength) and misfit marginal, respectively. Ninety specimens have been fabricated titanium cp, and sixty, cylindrical rods, obtained by casting of the brass rods, and thirty implant-supported frameworks, obtained by plaster die with four similar - Microunit implants (Connection), with ten repetitions for each group (control, TIG welding, laser welding). The specimens were invested in Rematitan Plus, according to the manufacturer instructions. The rings were subjected to thermal cycling and positioned in the machine of casting (Rematitan) under voltaic arc, vacuum and atmosphere of argon, with injection of titanium vacuumpressure. After cooling, were manually and airbone-particle abraded with aluminum oxide. The specimes cylindrical rods were randomly distributed in three groups, for tests, tensile and flexural strength: the control group (without welding), TIG welding and soldering laser. The above thirty-structures were randomly divided into three groups: I- one-piece-cast (control)-, II-B-after-TIG welding and III-B-after-Laser welding, the Group II-A, III-A, consisted of specimens before the process of welding: II-A-before-TIG welding and III-A before-Laser welding. The results for the test Traction were submitted to variance analysis ANOVA (p < 0.05) being observed difference between groups. The supplementary Tukey test (p = 0.05) showed that there was a difference between the control group (605.84 ± 19.83) and the methods of welding TIG (514.90 ± 37.76) and laser (515.85 ± 62.07). To test the Flexion nonparametric test Kruskal-Wallis showed that there was no statistically significant difference between the processes of TIG welding (1559.66) and Laser (1621.64), but the difference was significant between these groups and control (1908.75). For analysis of the results of marginal misfit implant-supported frameworks, the non-parametric Kruskal-Wallis test revealed that there was no statistically significant difference between groups after-TIG welding (250) and after- Laser welding (241), however, the control group (770) showed the largest misfit. With these and the limitations of this study TIG welding in may be to Laser welding.

The design of complex structures demands the prediction of possible fracture-dominant failure processes, due to the existence of unavoidable preexistent flaws and other defects, as well as sharps and cracks. On one hand, the complexity of the structure and the presence of many defects to be accounted for in the modeling can become the computational effort impracticable. On the other hand, it is important to seek the development of a computational framework based on some numerical method to study these problems. A way to overcome the difficulties mentioned, therefore making feasible the analysis of complex structures with many cracks, flaws and other defects, consists of combining a representative mechanical modeling with an efficient numerical method. This is precisely the fundamental aim of this work. Firstly, the Splitting Method is used aiming to build a representative modeling. Secondly, the Generalized Finite Element Method (GFEM) is chosen as an efficient numerical method, in which enrichment strategies of the approximated solution using stress functions in particular can be explored. The GFEM framework also allows avoiding the excessive refinement of the mesh, which increases the computational effort in conventional finite element analysis. In the Splitting Method, a kind of decomposition method, the original problem is subdivided in local and global problems which are then combined by imposing null traction at the crack surfaces. In this work, the Splitting Method was completely programmed in Python language and its use extended to analyze crack propagation including fatigue crack growth. The generated code presents in addition to several features related to Fracture Mechanics concepts, as the computation of the stress intensity factor (mode I and II) trough J Integral. Some examples are presented to depict the propagation of the cracks in multisite damage structures. It is shown that for this kind of problems the enrichment strategy provided by GFEM is essential. Moreover, the final example demonstrates that the computational tool allows for investigation of different possible crack scenarios with a low cost analysis. One concludes about the representativeness and efficiency of the methodology hereby proposed. / O projeto de estruturas complexas demanda a previsão de possíveis processos de ruptura governados por fraturamento, devido à existência de inevitáveis defeitos pré-existentes, como entalhes e fissuras. Por um lado, a complexidade da estrutura e a presença de muitos defeitos a serem considerados no modelo podem tornar a análise inviável devido ao esforço computacional necessário. Por outro lado, é importante procurar desenvolver uma estrutura computacional baseada em métodos numéricos para estudar estes problemas. Um modo de superar as dificuldades mencionadas, portanto tornando possível a análise de estruturas complexas com muitas fissuras e outros defeitos, consiste em combinar um modelo mecânico que seja representativo com um método numérico eficiente. Este é precisamente o objetivo fundamental deste trabalho. Primeiramente, o Método da Partição é utilizado para a construção de um modelo representativo. Em segundo lugar, o Método dos Elementos Finitos Generalizados (GFEM) é empregado por ser um método numérico eficiente, no qual as estratégias de enriquecimento da solução aproximada usando funções de tensão, em particular, podem ser exploradas. A estrutura do GFEM também permite evitar o excessivo refinamento da malha, que aumenta o esforço computacional em análises convencionais nas quais se utiliza o método dos elementos finitos. No Método da Partição, um tipo de método de decomposição, o problema original é subdividido em problemas locais e globais que são então combinados impondo-se a nulidade do vetor de tensões na superfície da fissura. Neste trabalho, o Método da Partição foi completamente programado em linguagem Python® e sua utilização estendida para analisar a propagação de fissuras, incluindo-se a associação do crescimento com a resposta em fadiga. Além disso, o código gerado apresenta diversas características relacionadas aos conceitos da Mecânica da Fratura, como o cálculo do fator de intensidade de tensão (modos I e II) mediante a Integral J. Alguns exemplos são apresentados para ilustrar a propagação de fissuras em estruturas multi-fraturadas. Mostra-se que para este tipo de problemas a estratégia de enriquecimento fornecida pelo GFEM é essencial. Além disso, o exemplo final comprova que a ferramenta computacional permite a investigação de diferentes possíveis cenários de fissuras com uma análise de baixo custo. Conclui-se sobre a representatividade e eficiência da metodologia proposta.

La technique du tissage consiste à créer un entrecroisement de fils perpendiculaires entre eux. Pour cela, il est nécessaire d'insérer un fil de trame à travers une nappe de fils de chaîne parallèles. L'étape de formation de la foule, consistant à séparer la nappe de chaîne pour libérer un espace d'insertion, est vecteur d'interactions interfilamentaires et de dommages induits dans la structure filamentaire. Un tel phénomène, rapporté au tissage de renforts de matériaux composites produit des dégradations de structure importantes et une diminution sensible des propriétés mécaniques du produit fini. Dans le contexte de la croissance du marché des matériaux composites haute performance à renforts tissés, il est nécessaire d'améliorer puis de maîtriser le procédé de tissage. Ainsi, pour optimiser le tissage d'étoffes multicouches à haute densité, nous disposons d’une machine Jacquard. Il s'agit d'une technique qui permet un pilotage individuel motorisé des fils de chaîne et qui offre des paramètres de foule particuliers. Le but de ces travaux sont d'étudier ces paramètres d'une part et de définir et analyser leurs effets sur le processus de tissage par ailleurs. Nous utilisons pour ces travaux du polyester multifilamentaire, ainsi qu'un dispositif de tissage particulier adapté au tissage technique multicouches. Nous constatons que le tissage multicouches de forte densité génère de nombreux frottements interfilamentaires qui dégradent les fils en provoquant de la fibrillation. L'observation de l'évolution de ce phénomène selon les différents paramètres Jacquard, permet tout d'abord de mieux le comprendre et le cerner. Elle permet ensuite de déterminer les configurations de tissage optimales pour assurer la qualité du tissage de renforts tissés. / Weaving basic structure is an orthogonally interlaced yarns plane, produced thanks to weft insertion across parallel warp yarns. Shedding is a major step for shed generation by warp yarns separation. Shedding may generate warp yarns interactions and yarn structure degradations because of density. Such a phenomenon becomes major with composite high density woven reinforcement where degradations and final product mechanical properties loss may become considerable. With high performance composites market growth, weaving process needs to be improved.A Jacquard shedding mechanism has been employed for high density multilayer woven fabric weaving optimization, as this technique enables warp yarns individual motorized driving with very particular shedding parameters. In this research, Jacquard shedding parameters have been studied so that their effects on the weaving process may be brought to light, with a specific weaving machine dedicated to multilayer weaving, where polyester multifilament yarns are used.It has been observed that high density multilayer weaving produces friction and many degradations during shedding between filaments because of the fibrillation phenomenon. Fibrillation has been examined and understood thanks to the observation of its evolution according to Jacquard shedding parameters. It has been the basis for optimal weaving parameter configurations which may be used for woven reinforcements composites quality improvement.