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Effect of cutting speed on the surface integrity of face milled 7050-T7451 aluminium workpieces

  • Pérez Guisado, Ion
  • Madariaga Zabala, Aitor
  • Arrazola Arriola, Pedro José
  • Cuesta Zabaljauregui, Mikel
  • Garay Araiko, Ainara
The guarantee of surface integrity has become a primary objective for researchers when analysing the reliability of machined aircraft aluminium alloy structural parts in high-speed machining. This work studies the effect of cutting speed on the surface integrity of face milled 7050-T7451 aluminium workpieces. First, 7050-T7451 aluminium workpieces were face milled under dry conditions using three cutting speeds (200, 800, 1400 m/min) at constant feed (0.20 mm/tooth) and depth of cut (1 mm). An indexable face milling cutter with a diameter of 50 mm with five uncoated inserts was used in the face milling tests. During the machining process, cutting forces were acquired employing a Kistler dynamometer in order to understand the influence of the mechanical load on the final surface quality. The surface roughness p roduced by the milling process was measured using a portable rugosimeter. The residual stresses generated by the cutting process were measured by the holedrilling technique. In addition, small specimens were cut out from the workpieces and microstructural alterations of the surface layer were analysed employing optical microscopy techniques. The results demonstrate that the magnitude of residual stresses and the thickness of the affected layer is sensitive to the cutting speed, while surface roughness and microstructural defects do not show significant variations for the tested conditions.

A novel soft tissue prediction methodology for orthognathic surgery based on probabilistic finite element modelling

  • Rodriguez Florez, Naiara
Repositioning of the maxilla in orthognathic surgery is carried out for functional and aesthetic purposes. Pre-surgical planning tools can predict 3D facial appearance by computing the response of the soft tissue to the changes to the underlying skeleton. The clinical use of commercial prediction software remains controversial, likely due to the deterministic nature of these computational predictions. A novel probabilistic finite element model (FEM) for the prediction of postoperative facial soft tissues is proposed in this paper. A probabilistic FEM was developed and validated on a cohort of eight patients who underwent maxillary repositioning and had pre- and postoperative cone beam computed tomography (CBCT) scans taken. Firstly, a variables correlation assessed various modelling parameters. Secondly, a design of experiments (DOE) provided a range of potential outcomes based on uniformly distributed input parameters, followed by an optimisation. Lastly, the second DOE iteration provided optimised predictions with a probability range. A range of 3D predictions was obtained using the probabilistic FEM and validated using reconstructed soft tissue surfaces from the postoperative CBCT data. The predictions in the nose and upper lip areas accurately include the true postoperative position, whereas the prediction under-estimates the position of the cheeks and lower lip. A probabilistic FEM has been developed and validated for the prediction of the facial appearance following orthognathic surgery. This method shows how inaccuracies in the modelling and uncertainties in executing surgical planning influence the soft tissue prediction and it provides a range of predictions including a minimum and maximum, which may be helpful for patients in understanding the impact of surgery on the face.

Nuevos Paradigmas de Análisis Basados en Contenidos para la Detección del Spam en RRSS

  • Ezpeleta Gallastegi, Enaitz
Tesis doctoral realizada por Enaitz Ezpeleta Gallastegi en Mondragon Unibertsitatea, dentro del grupo de Sistemas Inteligentes para Sistemas Industriales, dirigida por los Doctores Urko Zurutuza Ortega (Mondragon Unibertsitatea) y José María Gómez Hidalgo (Pragsis Technologies). La defensa se efectúo el 30 de septiembre de 2016 en Arrasate. El tribunal estuvo conformado por el Dr. Manel Medina Llinas (Universitat Politecnica de Catalunya), el Dr. Magnus Almgren (Chalmers University of Technology), el Dr. Igor Santos Grueiro (Universidad de Deusto), el Dr. José Ramón Méndez Reboredo (Universidad de Vigo) y el Dr. D. Iñaki Garitano Garitano (Mondragon Unibertsitatea). La tesis obtuvo una calificación de Sobresaliente Cum Laude y la mención "Doctor Europeus".

Development of Tools to Calculate the Vibroacoustic Performance of Electrical Machines in Lift Installations

  • Arrasate Aierbe, Javier
  • McCloskey Gómez, Alex
  • Telleria San Torcuato, Ander
Improper operation of the traction machine of a lift installation causes energy waste, vibrations and noise. The design of the machine must be optimum if energy efficiency and comfort specifications have to be satisfied. The vibrations and noise frequency spectra of electrical machines present manifest peaks at certain frequencies, multiples of the fundamental electrical frequency, that depend on the machine topology and its rotation velocity. Changes in its topology or in its mechanical properties (geometry, size, materials…) must be done in order to reduce the magnitude of peaks at certain excitation frequencies or to locate the excitation frequencies far from the natural frequencies of the structure or the lift installation. Machine designers need tools to calculate their vibroacoustic response once a certain design has been proposed, so they can modify it before a prototype is built in case the response is not acceptable. Numerical and analytical models to calculate the vibroacoustic response of electrical machines have been developed and experimentally validated. In this paper, the authors summarise the state of the art in modelling the vibroacoustic performance of electrical machines, provide some guidelines regarding the values to be assigned to the machine componets, and show some of the results obtained in their research work.

Influence of Microstructure on Chip Formation when Broaching Ferritic-Pearlitic Steels

  • Arrieta Galdós, Iñaki Mirena
  • Arrazola Arriola, Pedro José
Broaching is a specific process characterized by relatively low cutting speeds and uncut chip thicknesses. The latter is in the range of 0.1 to 0.25 mm in the roughing section of the tool but can decrease down to 0.0015 mm in the finishing one. This induces drastically different cutting behaviours compared to macroscale processes such as turning. The question of the scale effects in such conditions is thus clearly raising and especially the size and distribution of the microstructure. This paper proposes an investigation to assess the importance of the material heterogeneities on chip formation when broaching ferritic-pearlitic steels.

La contribución del diseño de servicios a la servitización de la industria manufacturera

  • Iriarte Azpiazu, Ion
La globalización, la mayor eficiencia en los costes de producción, la introducción de las tecnologías de la información en los procesos de manufactura y la saturación de los mercados entre otros factores obligan a las empresas manufactureras a reinventar continuamente sus propuestas de valor y los modelos de negocio que las sustentan. En este sentido, añadir o integrar servicios a la oferta productos es una de las estrategias que las empresas manufactureras pueden adoptar cara a lograr una mejora de su posición competitiva. Dicha estrategia, denominada como servitización es ya una realidad en diversos sectores industriales tanto a nivel global, estatal y regional. No obstante, la servitización conlleva a su vez numerosos riesgos dado que supone cambios importantes en la estrategia, cultura y estructuras organizativas de una empresa manufacturera. La industria está transitando hacia la oferta de soluciones integradas de producto-servicio, sin existir todavía un soporte metodológico contrastado y difundido. En este sentido, uno de los principales retos a los que se enfrentan las empresas manufactureras en los procesos de servitización es poseer enfoques, metodologías y herramientas prácticas para diseñar ofertas integradas de producto-servicio. El diseño de servicios ha sido sugerido como una disciplina capaz de apoyar procesos de servitización dado que presenta un enfoque práctico orientado al cliente y ofrece herramientas para la conceptualización, visualización y prototipado de sistemas complejos de producto-servicio. No obstante, los beneficios específicos derivados de la aplicación del diseño de servicios en empresas industriales manufactureras no han sido lo suficientemente estudiados. A través de una Investigación-Acción realizada en colaboración con empresas manufactureras pertenecientes al Área Industria de la Corporación MONDRAGON, esta tesis doctoral propone un modelo (INBEDI) para la adopción del diseño de servicios y determina cuáles son los beneficios de la aplicación del diseño de servicios en empresas industriales manufactureras inmersas en procesos de servitización. INBEDI es un modelo de aprendizaje a través de la colaboración universidad-empresa que se divide en tres etapas para: (i) mostrar el potencial del pensamiento del diseño de servicios (20 empresas participantes), (ii) experimentar con el diseño de servicios (5 empresas participantes [fabricante de productos deportivos, fabricante de electrodomésticos, fabricante de sistemas de elevación, fabricante de máquina herramienta y fabricante de componentes de automoción]), e (ii) implementar el diseño de servicios (2empresas participantes [fabricante de máquina herramienta y fabricante de componentes de automoción]. En cada una de las etapas las empresas aplican la metodología del Diseinu Berrikuntza Zentroa (DBZ) de Mondragon Unibertsitatea (MU) para para el diseño de ofertas integradas de producto-servicio. De esta manera se determinan cuáles son los beneficios de la aplicación del diseño de servicios en empresas industriales manufactureras inmersas en procesos de servitización. Las aportaciones más relevantes derivadas de esta investigación son: - Un modelo de aprendizaje validado para que una empresa industrial manufacturera inmersa en procesos de servitización adopte el enfoque y las herramientas del diseño de servicios (INBEDI). - La validación de que el diseño de servicios permite diseñar ofertas integradas de producto-servicio una vez que el reposicionamiento estratégico en el contínuum bien-servicio está ya definido. - La demostración de que en contextos industriales manufactureros, el diseño de servicios, más que servir como guía del proceso, funciona como “materializador” del mismo una vez que la organización haya definido el reposicionamiento estratégico en el contínuum bien-servicio. - La validación de que el diseño de servicios contribuye a los procesos de servitización de la industria a través de los siguientes beneficios: • Permite identificar necesidades no tecnológicas de los clientes. • Facilita la comprensión del valor de una oferta servitizada. • Hace tangible la oferta de servicio a través de los Touchpoints de servicio. • Contribuye a superar estrategias centradas en producto creando propuestas de valor orientadas a la experiencia del cliente. - La verificación de que las empresas manufactureras pueden aplicar el diseño de servicios para conseguir propuestas de valor más centradas en sus clientes, sin que estén pensando en una transición hacia los servicios como núcleo de su oferta., Globalizazioak, produkzio kostuen efizientzia hobekuntzek, ekoizpen prozesuetan informazio teknologiak txertatzeak eta merkatuen saturazioak, manufaktura-industriek euren balio proposamena eta sustengatzen dituzten negozio ereduak etengabe berrasmatzen egotera bultzatu ditu. Zentzu honetan, manufaktura-industriek euren lehiakortasuna hobetzeko produktu eskaintzari zerbitzuak gehitu edo integratzea estrategia egokia izan daiteke. Estrategia hau, zerbitizazioa deritzona, errealitate bilakatu da hainbat sektore industrialetan, eta mundu, estatu eta herrialde mailan izan du eragina. Hala ere, zerbitizazioak hainbat arrisku daramatza bere baitan, manufaktura-industrien estrategian, kulturan eta antolakuntzan aldaketa nabarmenak suposatzen baititu. Industria produktu-zerbitzuen eskaintza bateratuak eskaintzeko trantsizioan murgilduta dago, baina, oinarri metodologiko garbirik gabe. Zentzu honetan, zerbitizazio prozesuetan murgilduta dauden manufaktura-industriek duten erronka nagusietako bat, produktu-zerbitzu eskaintza bateratu horiek diseinatzeko beharrezkoak diren ikuspegi, metodologia eta erreminta praktikoak edukitzea da. Zerbitzu-diseinua zerbitizazio prozesuetan laguntzeko gai den diziplina moduan azaldu izan da, izan ere, bezeroarengana zuzendutako ikuspegi praktikoa dauka, eta produktu-zerbitzu sistema konplexuak sortu, bistaratu eta prototipatzeko tresnak eskaintzen ditu. Halere, zerbitzu-diseinua manufaktura-enpresa industrialetan aplikatzetik ondorioztatzen diren onura zehatzak ez dira behar beste aztertu. MONDRAGON taldeko industri arloko manufaktura-enpresatan egin den Ekintza-Ikerketa baten bitartez, doktorego-tesi honek, zerbitizazio prozesuetan murgilduta dauden enpresek, zerbitzu-diseinua integratu ahal izateko eredu bat proposatzen du (INBEDI). Era berean, zerbitzu-diseinuaren aplikazioak zerbitizazio prozesuetan murgilduta dauden enpresatan dituen onurak zehazten ditu. INBEDI unibertsitatearen eta enpresaren arteko elkarlanean oinarritzen den ikasketa eredu bat da, hiru etapatan banatuta dagoena: (i) zerbitzu-diseinuaren pentsamenduak duen potentziala erakustea (20 enpresa parte-hartzaile), (ii) zerbitzu-diseinuarekin esperimentatzea (5 enpresa parte-hartzaile [kirol-produktuen ekoizlea, etxetresnen ekoizlea, igogailu sistemen ekoizlea, makina-erreminta ekoizlea eta auto-moziorako osagarrien ekoizlea]), eta (iii) zerbitzu-diseinua inplementatzea (2 enpresa parte-hartzaile [makina-erreminta ekoizlea eta auto-moziorako osagarrien ekoizlea]). Etapa bakoitzean, parte hartu duten manufaktura-enpresek euren produktu-zerbitzu eskaintza bateratuaren diseinurako Mondragon Unibertsitateko (MU) Diseinu Berrikuntza Zentroaren (DBZ) metodologia aplikatu dute. Horrela, zerbitizazio prozesuetan murgilduta dauden manufaktura-enpresa industrialek zerbitzu-diseinua aplikatzerakoan dituzten onurak zehaztu dira. Ikerketa honetatik eratorritako ekarpen nabarmenenak honako hauek dira: - Zerbitizazio prozesu batean murgilduta dagoen manufaktura-enpresa batean zerbitzu-diseinuaren ikuspuntu eta erremintak integratzeko ikasketa eredu egiaztatu bat (INBEDI). - Behin manufaktura-enpresak produktu-zerbitzu continuum-ean birkokapen estrategikoa zehaztu duenean, industria-ekoizpen testuinguruetan zerbitzu-diseinuak zerbitizazio prozesuak gidatu beharrean prozesuaren “gauzatzaile” gisa funtzionatzen duenaren egiaztapena. - Behin produktu-zerbitzu contínuum-ean birkokapen estrategikoa zehaztua dagoenean, zerbitzu-diseinuak industria-ekoizpen testuinguruetan produktu-zerbitzu eskaintza bateratuak diseinatzea ahalbideratzen duenaren egiaztapena. - Zerbitzu-diseinuak zerbitizazio prozesuetan jarraian zehazten diren onuren bitartez sustengatzen dituenaren egiaztapena: • Bezeroen behar ez-teknologikoak identifikatzen laguntzen du. • Eskaintza zerbitizatu baten balioa ulertzen laguntzen du. • Zerbitzu eskaintza hautemangarria egiten du zerbitzuaren Touchpoint-en bitartez. • Produktuetan zentratutako estrategiak gainditzen laguntzen du, bezeroen esperientzian zentratuko balio proposamenak sortuz. - Manufaktura-enpresek bezeroetan zentratutako balio proposamenak sortzeko zerbitzu-diseinua aplikatu dezaketenaren egiaztapena, nahiz eta enpresak hauek zerbitzuetan oinarritutako balio proposamen batera aldatzea ez pentsatu., In today’s globalized world, factors such as continual improvements in production cost efficiency, information technologies in manufacturing processes and market saturation are pushing manufacturers to continuously reinvent their value propositions, and therefore their business models. Integrating services with products is a strategy many are using to improve their competitiveness. This strategy, known as servitization, is already present across the globe, nationally and regionally. However, though servitization has many potential benefits, it also involves risks that can affect to manufacturers’ strategy, culture, and organizational structures if not managed properly. Industry today is already moving towards integrated product-service offerings. However, it is doing so without sufficient methodological support. One of the main challenges that manufacturers face when undergoing servitization processes is to incorporate, methods and practical tools to design integrated product-service offerings. Service design has been proposed as a discipline to support manufacturers in their servitization processes. It provides a practical customer-oriented mindset as well as tools to conceptualize, visualize and prototype complex product-service systems. Nevertheless, at this time, there is little knowledge on the specific benefits of integrating service design into manufacturers already immersed in servitization. In order to address this issue, an Action-Research project was conducted in MONDRAGON Corporation’s Industry Area. The results culminated in a proposed model for the adoption of service design for manufacturers immersed in servitization processes called INBEDI. Moreover, the research was able to specify the benefits to be reaped from applying service design in such situations. INBEDI is a learning model based on university-business collaboration divided into three stages to: (i) show the potential of service design thinking (20 participant companies), (ii) experiment with service design (5 participant companies: a sports goods manufacturer, a household appliances manufacturer, an elevation systems manufacturer, a tool machinery builder, an automotive components manufacturer), and (iii) implement service design (conducted in two participant manufacturers: a tool machinery builder and an automotive components manufacturer). In each stage, manufactures apply Mondragon Unibertsitatea’s (MU) Diseinu Berrikuntza Zentroa’s (DBZ) methodology to design integrated product-service offers. This way this research was able to determine the specific benefits of service design applied to manufacturing servitization. The main contributions resulting from this research are: - A validated learning model for the adoption of a service design approach and tools for manufacturers immersed in servitization processes (INBEDI). - The validation that rather than being a guide of servitization, service design, in industrial manufacturing contexts works to facilitate the materialization of the process, once the organization has decided its strategic repositioning in the good-service continuum. - The validation that service design enables the design of integrated product-service offerings within industrial contexts once the manufacturer has defined the strategic repositioning in the good-service continuum. - The validation that service design benefits manufacturing servitization since it: • Identifies customer’s non-technological requirements. • Facilitates the understanding of value within servitized value propositions. • Makes the servitized value proposition tangible through service Touchpoints. • Helps companies to go beyond product-centered strategies by creating value propositions focused on customer experience. - The validation that manufacturers can apply service design to reach more customer-oriented value propositions, without supposing a transition in the product-service continuum towards services as the core offer.

Lanbide Heziketako ikastetxeak RIS3aren erronken aurrean. Nafarroako kasua, La formación profesional de Navarra. Hacia un nuevo modelo de centro y el reto de la FP dual, Vocational Education Training Centres in the context of the challenges associated with RIS3. The case of Navarre

  • Retegi Albisua, Javier
Berrikuntzako sistema erregionalek eta espezializazio estrategia adimentsuek heziketa teknikoan, ETEentzako zerbitzu teknologikoen prestakuntzan eta tokiko garapenean izandako hutsuneak azaldu ondoren, (LH) lanbide-heziketako ikastetxeek haien konponbidean bete lezaketen papera erakusten du artikulu honek. Horretarako, LHko ikastetxeek funtzio bakarrekoak izatetik funtzio anitzekoak izatera igaro behar dute. Ohikoak ez diren eginkizun berri horiek egin ahal izateak zer ikusia du LHko ikastetxe-motarekin eta LHko ikastetxeen barne eta kanpo-faktoreekin. Nafarroako kasuaren azterketak, aurrekoa argitzeaz gainera, erkidego horretan LHko ikastetxeen eredua eraldatu ahal izateko hainbat orientabide eskaintzen du., After exposing the shortcomings of regional innovation systems and smart specialisation strategies with regard to the technical training, the provision of technological services to SMEs and local development, this paper shows how Vocational Education and Training (VET) centres could contribute to solve them. For that, it is necessary to turn unitary VET centres into multi-functional VET centres. The performance of the new non-traditional functions by the VET centres depends on the prevalent type of centre, and internal and external factors to them. The analysis of the case of Navarre allows us, on top of illustrating the previous points, to draw some orientations about how the transformation of the VET centre model should be undertaken., Tras exponer las carencias que los sistemas regionales de innovación y las estrategias de especialización inteligente han presentado en el ámbito de la formación técnica, de los servicios tecnológicos a las pymes y del desarrollo local, el artículo muestra el papel que los centros educativos de Formación Profesional pueden jugar en su resolución. Para eso es necesaria la transformación de los centros de FP unitarios en centros integrados y multifuncionales. El desempeño de esas nuevas funciones no tradicionales depende de la tipología de centros imperante, y de factores internos y externos a estos. El análisis del caso de Navarra permite, además de ilustrar todo lo anterior, extraer orientaciones para llevar a cabo esa transformación del modelo de centro de FP en dicha comunidad.

Numerical simulation of U-Drawing test of Fortiform 1050 steel using different material models

  • Galdos Errasti, Lander
  • Saénz de Argandoña Fernández de Gorostiza, Eneko
  • Mendiguren Olaeta, Joseba
  • Mugarra Fernandez, Endika
  • Ulibarri Hernández, Unai
Steel has been used in vehicles from the automotive industry's inception. Different steel grades are continually being developed in order to satisfy new fuel economy requirements. For example, advanced high strength steel grades (AHSS) are widely used due to their good strength/weight ratio. Because each steel grade has a different microstructure composition and hardness, they show different behaviors when they are subjected to different strain paths. Similarly, the friction behavior when using different contact pressures and sliding velocities is considerably altered. Third generation steels present high yield strength together with high elongation capacity and strain hardening. Thus, it is logical to think that elastic modulus reduction and Bauschinger effect are important aspects when stamping these materials. Furthermore, high contact pressures arise when forming these steels and friction coefficient may significantly influence the numerical results. Stamping forming processes are nowadays usually optimized by numerical tools such as Finite Element Models. In order to get reliable results, these numerical tools require proper material and contact models in order to correctly predict the real behavior and flow of the materials. In the present paper, Fortiform 1050 material is deeply characterized using uniaxial and cyclic tension-compression tests. Friction coefficient is obtained using strip drawing tests. These results have been used to calibrate mixed kinematic-hardening material models as well as the friction. Finally, the geometrical accuracy of the different material models has been obtained by means of the comparison of the numerical predictions with experimental demonstrators obtained using a U-Drawing tester.

A Review in Fault Diagnosis and Health Assessment for Railway Traction Drives

  • Garramiola Aldai, Fernando
  • Madina Hernández, Patxi
  • Del Olmo, Jon
  • Almandoz Larralde, Gaizka
During the last decade, due to the increasing importance of reliability and availability, railway industry is making greater use of fault diagnosis approaches for early fault detection, as well as Condition-based maintenance frameworks. Due to the influence of traction drive in the railway system availability, several research works have been focused on Fault Diagnosis for Railway traction drives. Fault diagnosis approaches have been applied to electric machines, sensors and power electronics. Furthermore, Condition-based maintenance framework seems to reduce corrective and Time-based maintenance works in Railway Systems. However, there is not any publication that summarizes all the research works carried out in Fault diagnosis and Condition-based Maintenance frameworks for Railway Traction Drives. Thus, this review presents the development of Health Assessment and Fault Diagnosis in Railway Traction Drives during the last decade.

The MANTIS Reference Architecture

  • Larrinaga Barrenechea, Félix

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