http://hdl.handle.net/2117/3868 Wed, 19 Jun 2013 08:58:39 GMT 2013-06-19T08:58:39Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19361 Title: Improvement of the manufacturing process of abrasive stones for honing Authors: Buj Corral, Irene; Vivancos Calvet, Joan Abstract: In the present work, the mixing process of different components of abrasive stones of cubic boron nitride used for rough honing was studied. Stones are made by the sintering process of abrasive grains, a metallic bond, and a humectant that favors covering of each abrasive grain by the bond. Incorrect mixing of abrasive grains with the bond and humectant can result in stones with nonuniform abrasive grain distribution. As the abrasive stone wears out, grain distribution will vary and modify efficiency of the honing operation. Tin is the metal having the lowest melting point among metals in the bond. By means of a scanning electron microscope and energy-dispersive X-ray microanalysis, tin segregation was discarded, which could have led to abrasive grain segregation. Later, mixing tests of the different components of the stones were performed at different mixing times Tue, 21 May 2013 13:10:14 GMT http://hdl.handle.net/2117/19361 2013-05-21T13:10:14Z Buj Corral, Irene; Vivancos Calvet, Joan no Honing, Abrasive stone, Cubic boron nitride, Mixing In the present work, the mixing process of different components of abrasive stones of cubic boron nitride used for rough honing was studied. Stones are made by the sintering process of abrasive grains, a metallic bond, and a humectant that favors covering of each abrasive grain by the bond. Incorrect mixing of abrasive grains with the bond and humectant can result in stones with nonuniform abrasive grain distribution. As the abrasive stone wears out, grain distribution will vary and modify efficiency of the honing operation. Tin is the metal having the lowest melting point among metals in the bond. By means of a scanning electron microscope and energy-dispersive X-ray microanalysis, tin segregation was discarded, which could have led to abrasive grain segregation. Later, mixing tests of the different components of the stones were performed at different mixing times http://hdl.handle.net/2117/19161 Title: Estudio comparativo del conformado en caliente de un acero microaleado usando criterios termodinámicos continuos y criterios fenomenológicos Authors: Alcelay Larrión, José Ignacio; Al Omar Mesnaoui, Anas; Prado Pozuelo, José Manuel Abstract: En las últimas décadas, los mapas de procesado han sido ampliamente utilizados para diseñar, controlar y optimizar los procesos de conformado en caliente. En el presente trabajo, se presenta un estudio comparativo entre mapas de procesado elaborados usando criterios termodinámicos continuos y criterios fenomenológicos. Por ello, se llevaron a cabo ensayos de compresión en caliente en el rango de temperaturas 900 - 1150 ºC y de velocidades de deformación i: = 10-4 - 10 s-1 . El comportamiento en caliente del acero estudiado ha sido estudiado analizando las curvas de fluencia y la interacción entre el comportamiento microestructural y los parámetros de control del proceso de deformación. El estudio comparativo de los mapas de procesado muestra la diferencia entre las posiciones de los distintos dominios de deformación plástica, según el criterio de inestabilidad usado. Además, el análisis de dichos mapas indica que el acero estudiado no sufre ningún tipo de inestabilidad plástica . Sin embargo, los mapas correspondientes a la deformación ¡; = 0,6 revelan la existencia de un dominio de recristalización dinámica, considerado como el dominio más eficiente dentro de la región segura de procesado. Este dominio está centrado a 1150 ºC y 10 s·1.; In the last decades, processing maps have been widely used to design, control and optimize hot forming processes. In this paper, we present a comparative study of processing maps constructed using phenomenological and thermodynamic continuum criteria. Therefore, hot compression tests were carried out in the temperature and strain rate ranging from 900 to 1150 ºC and 10-• to 10 s-1. The hot deformation behavior of studied steel has been investigated analyzing the flow curves and the interaction between the microstructural behavior and parameters control of the deformation process. The comparative study of processing maps show the difference between the positions of plastic deformation domains predicted by the two instability criteria. The analysis of the maps indicates that the steel does not undergo any plastic instability. However, the maps corresponding to deformation E = 0,6 reveal the existence of a domain of dynamic recrystallization, considered the most efficient domain within the safe region processing. This domain is centered at 1150 ºC and 10 s-1. Fri, 10 May 2013 13:22:35 GMT http://hdl.handle.net/2117/19161 2013-05-10T13:22:35Z Alcelay Larrión, José Ignacio; Al Omar Mesnaoui, Anas; Prado Pozuelo, José Manuel no En las últimas décadas, los mapas de procesado han sido ampliamente utilizados para diseñar, controlar y optimizar los procesos de conformado en caliente. En el presente trabajo, se presenta un estudio comparativo entre mapas de procesado elaborados usando criterios termodinámicos continuos y criterios fenomenológicos. Por ello, se llevaron a cabo ensayos de compresión en caliente en el rango de temperaturas 900 - 1150 ºC y de velocidades de deformación i: = 10-4 - 10 s-1 . El comportamiento en caliente del acero estudiado ha sido estudiado analizando las curvas de fluencia y la interacción entre el comportamiento microestructural y los parámetros de control del proceso de deformación. El estudio comparativo de los mapas de procesado muestra la diferencia entre las posiciones de los distintos dominios de deformación plástica, según el criterio de inestabilidad usado. Además, el análisis de dichos mapas indica que el acero estudiado no sufre ningún tipo de inestabilidad plástica . Sin embargo, los mapas correspondientes a la deformación ¡; = 0,6 revelan la existencia de un dominio de recristalización dinámica, considerado como el dominio más eficiente dentro de la región segura de procesado. Este dominio está centrado a 1150 ºC y 10 s·1. http://hdl.handle.net/2117/18352 Title: Experiences in Agile R&D Project Management for New Product Design and Development in the Automotive Industry Authors: Rodríguez Gutiérrez, Rodulfo; Minguella Canela, Joaquim; Fenollosa i Artés, Felip; Ventayol Femenias, Bartomeu; Santos López, M. Antonia de los Abstract: In the past 20 years technology has advanced at incredible speed. Product life cycle has decreased tremendously. Innovation in product and process has become essential for companies’ survival. Products are not longer simple, they integrate different and new technologies and therefore manufacturing process is evolving towards intelligent, virtual, sustainable and high performance factories. In spite of all these changes in manufacturing, R&D project management has not evolved at the same pace. The authors have approached a new way of conducting R&D projects that can integrate IT Agile Project Management and Innovation Management best practices. As a result the present paperformulates a methodology for agile new product and process development that can match the actual product cycle development requirements, shortening project life cycles but keeping space for innovation and creativity. The methodology has been applied in R&D projects for the automotive industry to develop new automated manufacturing cells for production lines. The experience allowed to identify the key processes with more risk during the project execution and helped us to gather information to keep improving the methodology. Fri, 15 Mar 2013 14:39:18 GMT http://hdl.handle.net/2117/18352 2013-03-15T14:39:18Z Rodríguez Gutiérrez, Rodulfo; Minguella Canela, Joaquim; Fenollosa i Artés, Felip; Ventayol Femenias, Bartomeu; Santos López, M. Antonia de los no In the past 20 years technology has advanced at incredible speed. Product life cycle has decreased tremendously. Innovation in product and process has become essential for companies’ survival. Products are not longer simple, they integrate different and new technologies and therefore manufacturing process is evolving towards intelligent, virtual, sustainable and high performance factories. In spite of all these changes in manufacturing, R&D project management has not evolved at the same pace. The authors have approached a new way of conducting R&D projects that can integrate IT Agile Project Management and Innovation Management best practices. As a result the present paperformulates a methodology for agile new product and process development that can match the actual product cycle development requirements, shortening project life cycles but keeping space for innovation and creativity. The methodology has been applied in R&D projects for the automotive industry to develop new automated manufacturing cells for production lines. The experience allowed to identify the key processes with more risk during the project execution and helped us to gather information to keep improving the methodology. http://hdl.handle.net/2117/18336 Title: Desarrollo de una herramienta de selección de procesos de fabricación basada en técnicas de Inteligencia Artificial Authors: Munguía Valenzuela, Francisco Javier; Minguella Canela, Joaquim Abstract: La gran cantidad de procesos de fabricación con los que cuentan actualmente tanto ingenieros como diseñadores industriales hace necesaria la utilización de sistemas basados en ordenador como sistemas de análisis y selección de procesos tipo CAE o CAPP. Aunque la selección de alternativas de fabricación es una tarea trivial para centros con una variedad limitada de tecnologías o bien para profesionales con un alto nivel de especialización en un reducido número de procesos, el proceso de selección no resulta tan trivial cuando lo que interesa analizar son nuevas tecnologías o procesos para los cuales no existe el conocimiento práctico necesario. El presente trabajo en marcado en el proyecto MAQMA se encarga de modelar un sistema concurrente para la evaluación de procesos de Rapid Manufacturing apoyado en técnicas de inteligencia artificial como redes neuronales, lógica difusa y sistemas expertos. Se presentará la aplicación piloto a fin de ilustrar el funcionamiento de dichas herramientas en un sistema integrado para facilitar las decisiones en este innovador campo de la fabricación. Fri, 15 Mar 2013 09:59:33 GMT http://hdl.handle.net/2117/18336 2013-03-15T09:59:33Z Munguía Valenzuela, Francisco Javier; Minguella Canela, Joaquim no La gran cantidad de procesos de fabricación con los que cuentan actualmente tanto ingenieros como diseñadores industriales hace necesaria la utilización de sistemas basados en ordenador como sistemas de análisis y selección de procesos tipo CAE o CAPP. Aunque la selección de alternativas de fabricación es una tarea trivial para centros con una variedad limitada de tecnologías o bien para profesionales con un alto nivel de especialización en un reducido número de procesos, el proceso de selección no resulta tan trivial cuando lo que interesa analizar son nuevas tecnologías o procesos para los cuales no existe el conocimiento práctico necesario. El presente trabajo en marcado en el proyecto MAQMA se encarga de modelar un sistema concurrente para la evaluación de procesos de Rapid Manufacturing apoyado en técnicas de inteligencia artificial como redes neuronales, lógica difusa y sistemas expertos. Se presentará la aplicación piloto a fin de ilustrar el funcionamiento de dichas herramientas en un sistema integrado para facilitar las decisiones en este innovador campo de la fabricación. http://hdl.handle.net/2117/18093 Title: Prediction of the force of the ball-burnishing, physical model Authors: González Rojas, Hernan Alberto; Travieso Rodriguez, Jose Antonio Abstract: En este artículo se desarrolla un modelo físico para predecir la fuerza en el bruñido con bola. El modelo está construido en base a la teoría de la plasticidad. En el desarrollo del modelo se ha encontrado el número adimesional B que caracteriza el problema de deformación plástica en el bruñido con bola. Los experimentos realizados en acero y aluminio permiten validar el modelo y destacar la correcta predicción de las tendencias de comportamiento del bruñido con bola. Wed, 06 Mar 2013 11:46:19 GMT http://hdl.handle.net/2117/18093 2013-03-06T11:46:19Z González Rojas, Hernan Alberto; Travieso Rodriguez, Jose Antonio no En este artículo se desarrolla un modelo físico para predecir la fuerza en el bruñido con bola. El modelo está construido en base a la teoría de la plasticidad. En el desarrollo del modelo se ha encontrado el número adimesional B que caracteriza el problema de deformación plástica en el bruñido con bola. Los experimentos realizados en acero y aluminio permiten validar el modelo y destacar la correcta predicción de las tendencias de comportamiento del bruñido con bola. http://hdl.handle.net/2117/17859 Title: Design of an innovative bike brake integrated into the wheel hub Authors: Crescenti, M.; Ortiz Marzo, José Antonio Abstract: The public urban bike services demand more robust mechanical devices to resist misuse and vandalism. An innovative wheel hub integrated bike brake was designed making use of CAD-3D and numerical analysis tools and considering both technological and economical criteria. Unlike the other existing hub integrated bike brakes, the new design ensures an homogeneous pressure distribution on the braking pads, which maximizes its lifespan, reduces the maintenance costs and guarantees an uniform performance along the brake lifespan. As the other existing hub integrated brakes, the new design is very compact, robust and low sensitive to adverse environmental conditions and dirt. Mon, 18 Feb 2013 16:15:41 GMT http://hdl.handle.net/2117/17859 2013-02-18T16:15:41Z Crescenti, M.; Ortiz Marzo, José Antonio no The public urban bike services demand more robust mechanical devices to resist misuse and vandalism. An innovative wheel hub integrated bike brake was designed making use of CAD-3D and numerical analysis tools and considering both technological and economical criteria. Unlike the other existing hub integrated bike brakes, the new design ensures an homogeneous pressure distribution on the braking pads, which maximizes its lifespan, reduces the maintenance costs and guarantees an uniform performance along the brake lifespan. As the other existing hub integrated brakes, the new design is very compact, robust and low sensitive to adverse environmental conditions and dirt. http://hdl.handle.net/2117/17763 Title: Evolution of roughness parameters along polishing tests of previously ground surfaces Authors: Buj Corral, Irene; Vivancos Calvet, Joan Abstract: In polishing tests, precise determination of polishing time needed is difficult, since representation of surface roughness against polishing time leads to an asymptotic curve. In the present work, results of the polishing tests of previously ground surfaces are presented. Different roughness parameters were considered. Grinding wheels of 100 and 150 Norton grain size respectively were used. Cutting speed was 25 m s-1 and depth of cut was 0.02 mm. Two different feeds were considered: 9 m min-1 and 15 m min-1. A polishing test was performed by means of corundum polishing pads of grain size 2500. Results show that, the higher the initial grain size of the grinding wheel, the higher initial roughness is as expected. Amplitude roughness parameters such as Ra and Rq decrease with polishing time. Regarding material percentage parameters, Rk and Rpk decrease more sharply than amplitude roughness parameters in the first 20 s of the polishing test, and afterwards decrease slightly. Rvk decreases more slowly than amplitude roughness parameters along the polishing test. Keywords: grinding, polishing, roughness parameters Thu, 14 Feb 2013 12:49:34 GMT http://hdl.handle.net/2117/17763 2013-02-14T12:49:34Z Buj Corral, Irene; Vivancos Calvet, Joan no In polishing tests, precise determination of polishing time needed is difficult, since representation of surface roughness against polishing time leads to an asymptotic curve. In the present work, results of the polishing tests of previously ground surfaces are presented. Different roughness parameters were considered. Grinding wheels of 100 and 150 Norton grain size respectively were used. Cutting speed was 25 m s-1 and depth of cut was 0.02 mm. Two different feeds were considered: 9 m min-1 and 15 m min-1. A polishing test was performed by means of corundum polishing pads of grain size 2500. Results show that, the higher the initial grain size of the grinding wheel, the higher initial roughness is as expected. Amplitude roughness parameters such as Ra and Rq decrease with polishing time. Regarding material percentage parameters, Rk and Rpk decrease more sharply than amplitude roughness parameters in the first 20 s of the polishing test, and afterwards decrease slightly. Rvk decreases more slowly than amplitude roughness parameters along the polishing test. Keywords: grinding, polishing, roughness parameters http://hdl.handle.net/2117/17762 Title: Influence of humectant quantity and mixing time on the quality of abrasive stones used in honing processes Authors: Buj Corral, Irene; Vivancos Calvet, Joan; Corominas Rovira, Laura Abstract: In the manufacturing process of abrasive stones with cubic boron nitride (CBN) as abrasive and metallic binder, some differences were observed regarding abrasive density at different heights of the stones. If abrasive density is too low, honing stones do not cut the material properly. Honing stones are obtained by means of sintering processes. Previously, a humectant material is added to abrasive grains, and then they are mixed with metallic binder. Humectant is used to assure covering of each abrasive grain with binder. In the present work, along the manufacturing process of honing stones, quality of the mixing process of components was assessed by means of two different parameters: covering degree of grains by binder (CD) and homogeneity degree (HD) of the mix before sintering process. Both parameters are calculated by means of weight measurement in the mixing step. Different quantities of humectant and different mixing times were taken into account. A higher quantity of humectant implies a higher covering degree, leading to more homogeneous honing stones. For this reason, highest quantity of humectant is recommended within the range studied. However, a certain mixing time is required to assure homogeneity of the mix prior to sintering. Thu, 14 Feb 2013 12:32:18 GMT http://hdl.handle.net/2117/17762 2013-02-14T12:32:18Z Buj Corral, Irene; Vivancos Calvet, Joan; Corominas Rovira, Laura no In the manufacturing process of abrasive stones with cubic boron nitride (CBN) as abrasive and metallic binder, some differences were observed regarding abrasive density at different heights of the stones. If abrasive density is too low, honing stones do not cut the material properly. Honing stones are obtained by means of sintering processes. Previously, a humectant material is added to abrasive grains, and then they are mixed with metallic binder. Humectant is used to assure covering of each abrasive grain with binder. In the present work, along the manufacturing process of honing stones, quality of the mixing process of components was assessed by means of two different parameters: covering degree of grains by binder (CD) and homogeneity degree (HD) of the mix before sintering process. Both parameters are calculated by means of weight measurement in the mixing step. Different quantities of humectant and different mixing times were taken into account. A higher quantity of humectant implies a higher covering degree, leading to more homogeneous honing stones. For this reason, highest quantity of humectant is recommended within the range studied. However, a certain mixing time is required to assure homogeneity of the mix prior to sintering. http://hdl.handle.net/2117/17669 Title: Caracterización del ángulo de inclinación en los planos sagital y frontal de pacientes enfermos de Parkinson utilizando un acelerómetero triaxial Authors: Cardona Foix, Salvador; Zayas Figueras, Enrique Ernesto; González Rojas, Hernan Alberto; Chaná Cuevas, Pedro Abstract: Una de las enfermedades que con frecuencia se presenta en la actualidad en personas adultas es la enfermedad de Parkinson (EP). En el proceso de diagnóstico clínico de la misma se utilizan diferentes exámenes clínicos siendo uno de ellos el examen Levantarse-Sentarse. La determinación precisa del estado de una persona para saber si padece Parkinson o no y el grado de avance de la enfermedad de un paciente se realiza básicamente mediante diagnósticos clínicos y utilizando las escalas Hoehn & Yarh y la UPDRS de progresión y severidad de la enfermedad. En estas escalas el diagnóstico se hace a través de una valoración visual de los médicos especialistas del comportamiento del paciente. El presente trabajo expone un estudio del movimiento de un grupo de diez pacientes enfermos de Parkinson y de cinco controles −personas sanas− utilizando un acelerómetro triaxial colocado en la espalda del paciente, durante la realización del examen antes citado. El objetivo del estudio es obtener información del proceso de movimiento e identificar variables que permitan diferenciar el grupo de controles y el de pacientes. Tue, 12 Feb 2013 15:49:55 GMT http://hdl.handle.net/2117/17669 2013-02-12T15:49:55Z Cardona Foix, Salvador; Zayas Figueras, Enrique Ernesto; González Rojas, Hernan Alberto; Chaná Cuevas, Pedro no Una de las enfermedades que con frecuencia se presenta en la actualidad en personas adultas es la enfermedad de Parkinson (EP). En el proceso de diagnóstico clínico de la misma se utilizan diferentes exámenes clínicos siendo uno de ellos el examen Levantarse-Sentarse. La determinación precisa del estado de una persona para saber si padece Parkinson o no y el grado de avance de la enfermedad de un paciente se realiza básicamente mediante diagnósticos clínicos y utilizando las escalas Hoehn & Yarh y la UPDRS de progresión y severidad de la enfermedad. En estas escalas el diagnóstico se hace a través de una valoración visual de los médicos especialistas del comportamiento del paciente. El presente trabajo expone un estudio del movimiento de un grupo de diez pacientes enfermos de Parkinson y de cinco controles −personas sanas− utilizando un acelerómetro triaxial colocado en la espalda del paciente, durante la realización del examen antes citado. El objetivo del estudio es obtener información del proceso de movimiento e identificar variables que permitan diferenciar el grupo de controles y el de pacientes. http://hdl.handle.net/2117/17526 Title: Characterization of test results of the performance of additive manufacturing parts obtained by selective laser sintering processes incorporating glass and carbon fibres Authors: Roure Fernández, Francisco; Pastor Artigues, María Magdalena; Ferrer Ballester, Miquel; Minguella Canela, Joaquim; Uceda Molera, R.; Arjona Mora, A. Abstract: Selective Laser Sintering, and in general Additive Manufacturing Processes are becoming mature technologies; in the sense that after many years of market introduction there are some well-known manufacturers that provide fully operative systems that are even utilized for direct parts manufacturing. However, the parts final users are becoming more and more demanding, so they can integrate the AM parts in complex assemblies; thus increasing the materials requirements and the final part’s properties. Building into previous works on AM materials, the purpose of the present paper is to explore the properties yielded by the introduction of Glass short fibre randomly to polyamide and to assess the performance of the probe parts taking into consideration the AM manufacturing direction in the building platform and the Energy Density applyied to the operations. Folowing to a literature review, the paper first describes the statistical approach and the samples preparation. Then, the samples are characterized by tensile tests and the properties of the material are described for the different manufacturing strategies adopted. The outcomes of the work are highly applicable to the AM parts manufacture process, as the construction of parts in the building platform is usually dictated by the objective of optimizing the use of the total volume; thus implying that not all parts are manufactured in the same main construction direction. Tue, 29 Jan 2013 09:11:37 GMT http://hdl.handle.net/2117/17526 2013-01-29T09:11:37Z Roure Fernández, Francisco; Pastor Artigues, María Magdalena; Ferrer Ballester, Miquel; Minguella Canela, Joaquim; Uceda Molera, R.; Arjona Mora, A. no Selective Laser Sintering, and in general Additive Manufacturing Processes are becoming mature technologies; in the sense that after many years of market introduction there are some well-known manufacturers that provide fully operative systems that are even utilized for direct parts manufacturing. However, the parts final users are becoming more and more demanding, so they can integrate the AM parts in complex assemblies; thus increasing the materials requirements and the final part’s properties. Building into previous works on AM materials, the purpose of the present paper is to explore the properties yielded by the introduction of Glass short fibre randomly to polyamide and to assess the performance of the probe parts taking into consideration the AM manufacturing direction in the building platform and the Energy Density applyied to the operations. Folowing to a literature review, the paper first describes the statistical approach and the samples preparation. Then, the samples are characterized by tensile tests and the properties of the material are described for the different manufacturing strategies adopted. The outcomes of the work are highly applicable to the AM parts manufacture process, as the construction of parts in the building platform is usually dictated by the objective of optimizing the use of the total volume; thus implying that not all parts are manufactured in the same main construction direction. http://hdl.handle.net/2117/17008 Title: Comparativa del proceso de bruñido con bola en máquinas de 3 y 5 ejes en piezas de aluminio A92017 y A 96351 Authors: Travieso Rodriguez, Jose Antonio; Sánchez Egea, Antonio José; Nápoles Alberro, Amelia; Huertas Talón, José Luis; Gómez Gras, David; González Rojas, Hernan Alberto Fri, 23 Nov 2012 09:57:12 GMT http://hdl.handle.net/2117/17008 2012-11-23T09:57:12Z Travieso Rodriguez, Jose Antonio; Sánchez Egea, Antonio José; Nápoles Alberro, Amelia; Huertas Talón, José Luis; Gómez Gras, David; González Rojas, Hernan Alberto no http://hdl.handle.net/2117/17007 Title: Caracterización de la placa de una herramienta de bruñido con bola asistida por una vibración ultrasónica Authors: Gómez Gras, David; González Rojas, Hernan Alberto; Travieso Rodriguez, Jose Antonio; Nápoles Alberro, Amelia; Sánchez Egea, Antonio José Abstract: En la industrial actual existen una gran cantidad de componentes mecánicos de máquinas-herramienta, automóviles, aviones, trenes, barcos, moldes, matrices de conformación, y muchas otras piezas; que deben tener una buena rugosidad superficial, una tolerancia geométrica concreta, un grado de dureza superficial elevado y unos valores de resistencia mecánica considerables para poder hacer frente a sus prestaciones. En los últimos años ha crecido notoriamente la cantidad de investigación asociada a los diferentes procesos que sean capaces de dejar en estas piezas, las características adecuadas para que puedan cumplir dichas prestaciones. A día de hoy se cuenta con un proceso capaz de solventar con éxito todas estas necesidades: el bruñido con bola, aunque éste también presenta sus limitaciones en cuanto a qué materiales se pueden bruñir, y cómo varía las propiedades de éstos. El presente trabajo aborda la caracterización de la placa vibrante de una herramienta de bruñido asistida por una vibración de alta frecuencia. Se espera que dicha vibración contribuya a hacer más fácil el desarrollo de este proceso de acabado, puesto que la misma debería ayudar a deformar con mayor facilidad el material de la pieza que se trabaja. Al final se obtienen las dimensiones óptimas para la placa de la herramienta, así como el modelo matemático que caracteriza su funcionamiento. Fri, 23 Nov 2012 09:51:10 GMT http://hdl.handle.net/2117/17007 2012-11-23T09:51:10Z Gómez Gras, David; González Rojas, Hernan Alberto; Travieso Rodriguez, Jose Antonio; Nápoles Alberro, Amelia; Sánchez Egea, Antonio José no En la industrial actual existen una gran cantidad de componentes mecánicos de máquinas-herramienta, automóviles, aviones, trenes, barcos, moldes, matrices de conformación, y muchas otras piezas; que deben tener una buena rugosidad superficial, una tolerancia geométrica concreta, un grado de dureza superficial elevado y unos valores de resistencia mecánica considerables para poder hacer frente a sus prestaciones. En los últimos años ha crecido notoriamente la cantidad de investigación asociada a los diferentes procesos que sean capaces de dejar en estas piezas, las características adecuadas para que puedan cumplir dichas prestaciones. A día de hoy se cuenta con un proceso capaz de solventar con éxito todas estas necesidades: el bruñido con bola, aunque éste también presenta sus limitaciones en cuanto a qué materiales se pueden bruñir, y cómo varía las propiedades de éstos. El presente trabajo aborda la caracterización de la placa vibrante de una herramienta de bruñido asistida por una vibración de alta frecuencia. Se espera que dicha vibración contribuya a hacer más fácil el desarrollo de este proceso de acabado, puesto que la misma debería ayudar a deformar con mayor facilidad el material de la pieza que se trabaja. Al final se obtienen las dimensiones óptimas para la placa de la herramienta, así como el modelo matemático que caracteriza su funcionamiento. http://hdl.handle.net/2117/16536 Title: Influencia del proceso de bruñido con bola sobre la dureza y las tensiones residuales en el aluminio A92017 Authors: Travieso Rodriguez, Jose Antonio; González Rojas, Hernan Alberto; Gómez Gras, David; Nápoles Alberro, Amelia; Sánchez Egea, Antonio José Abstract: El bruñido con bola se realiza, para mejorar el acabado de las piezas que han sido mecanizadas y para obtener una superficie más dura con tensiones residuales a compresión. De este modo se obtendrá una mayor resistencia al desgaste y a la fatiga. En este trabajo se presentan los resultados de las pruebas realizadas con dicho proceso aplicado a piezas convexas de aluminio A92017. Se presentan como resultados, las mediciones de dureza y de tensiones residuales obtenidas antes y después del bruñido y se extraen conclusiones sobre la mejora de estas propiedades en las superficies bruñidas. Thu, 20 Sep 2012 11:42:55 GMT http://hdl.handle.net/2117/16536 2012-09-20T11:42:55Z Travieso Rodriguez, Jose Antonio; González Rojas, Hernan Alberto; Gómez Gras, David; Nápoles Alberro, Amelia; Sánchez Egea, Antonio José no El bruñido con bola se realiza, para mejorar el acabado de las piezas que han sido mecanizadas y para obtener una superficie más dura con tensiones residuales a compresión. De este modo se obtendrá una mayor resistencia al desgaste y a la fatiga. En este trabajo se presentan los resultados de las pruebas realizadas con dicho proceso aplicado a piezas convexas de aluminio A92017. Se presentan como resultados, las mediciones de dureza y de tensiones residuales obtenidas antes y después del bruñido y se extraen conclusiones sobre la mejora de estas propiedades en las superficies bruñidas. http://hdl.handle.net/2117/16521 Title: Flexural properties and failure mechanism assessment for additive manufactured lom bars on different building orientations Authors: Olivier, D.; Travieso Rodriguez, Jose Antonio; Borrós, S; Reyes Pozo, Guillermo Abstract: Plastic Laminated Object Manufacturing has not been assessed from the flexural properties point of view. The deflection range in parts manufactured by this technique is wider than in parts fabricated by other additive manufacturing methods like SLS or FDM. This fact has increased the interest on the final application of these parts rather than restricted to Rapid Prototyping applications. In this study it will be compared the impact of building orientation and geometric features of parts over the flexural properties. Through optical observation it will be studied the failure mechanism. Wed, 19 Sep 2012 09:42:51 GMT http://hdl.handle.net/2117/16521 2012-09-19T09:42:51Z Olivier, D.; Travieso Rodriguez, Jose Antonio; Borrós, S; Reyes Pozo, Guillermo no FDM, Flexural testing, Rapid manufacturing, Rapid prototyping, Additive Manufacturing, Building orientation, Failure mechanism, Flexural properties, Flexural testing, Geometric feature, Laminated object manufacturing, Optical observations, Rapid prototyping applications Plastic Laminated Object Manufacturing has not been assessed from the flexural properties point of view. The deflection range in parts manufactured by this technique is wider than in parts fabricated by other additive manufacturing methods like SLS or FDM. This fact has increased the interest on the final application of these parts rather than restricted to Rapid Prototyping applications. In this study it will be compared the impact of building orientation and geometric features of parts over the flexural properties. Through optical observation it will be studied the failure mechanism. http://hdl.handle.net/2117/15287 Title: Successes and challenges of a Collaborative-PBL Program in Engineering Degrees Authors: González Díez, David; Font Andreu, Jorge; Salán Ballesteros, Maria Núria; García-Almiñana, Daniel; Ortiz Marzo, José Antonio; Mudarra López, Miguel; Griful Ponsati, Eulàlia Abstract: This paper presents an extracurricular program called INSPIRE3 that has been implemented by the ETSEIAT (Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa), a center belonging to the UPC-BarcelonaTech (Universitat Politècnica de Catalunya). This program is mainly aimed at facilitating cross-curricular skills and developing abilities among students through collaborative-project based learning. The projection of an attractive external image of engineering degrees offered by ETSEIAT in order to increase the enrollment in such degrees is a secondary goal of this program. Under INSPIRE3, several real, challenging and multidisciplinary engineering projects are currently under development. The main feature of this program is that the subjects of the projects are proposed by the students themselves. In this paper, INSPIRE3 motivation, program management and implementation process are described and a short description of projects under development is also given. Tue, 21 Feb 2012 14:51:25 GMT http://hdl.handle.net/2117/15287 2012-02-21T14:51:25Z González Díez, David; Font Andreu, Jorge; Salán Ballesteros, Maria Núria; García-Almiñana, Daniel; Ortiz Marzo, José Antonio; Mudarra López, Miguel; Griful Ponsati, Eulàlia no This paper presents an extracurricular program called INSPIRE3 that has been implemented by the ETSEIAT (Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa), a center belonging to the UPC-BarcelonaTech (Universitat Politècnica de Catalunya). This program is mainly aimed at facilitating cross-curricular skills and developing abilities among students through collaborative-project based learning. The projection of an attractive external image of engineering degrees offered by ETSEIAT in order to increase the enrollment in such degrees is a secondary goal of this program. Under INSPIRE3, several real, challenging and multidisciplinary engineering projects are currently under development. The main feature of this program is that the subjects of the projects are proposed by the students themselves. In this paper, INSPIRE3 motivation, program management and implementation process are described and a short description of projects under development is also given.