Artículos de revista DIMEM - MEMIS Aldizkari artikuluak
Permanent URI for this collection
Browse
Browsing Artículos de revista DIMEM - MEMIS Aldizkari artikuluak by Title
Now showing 1 - 20 of 72
Results Per Page
Sort Options
Publication Open Access Análisis de la influencia de las condiciones de proceso sobre el acabado superficial de materiales cerámicos fabricados por electroerosión(CENIM, 2004) Puertas Arbizu, Ignacio; Luis Pérez, Carmelo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaEl mecanizado por electroerosión (en inglés, Electrical Discharge Machining, EDM) constituye una alternativa emergente frente a otros procesos de fabricación de materiales cerámicos conductores, tales como: mecanizado por láser, mecanizado electroquímico, chorro de agua con abrasivos, mecanizado por ultrasonidos y rectificado con muela de diamante. Debido a su interés en el ámbito industrial, en este trabajo se lleva a cabo un estudio de la influencia de las condiciones de operación sobre el aspecto superficial de tres materiales cerámicos conductores: carburo de boro prensado en caliente (B4C), carburo de silicio infiltrado con silicio (SiSiC) y carburo de wolframio en matriz metálica de cobalto (WC-Co), electroerosionados bajo diferentes condiciones de mecanizado y para el caso particular de regímenes de acabado (Ra ≤ 1 μm).Publication Open Access Análisis de la influencia del tratamiento térmico de envejecimiento en la modificación de las propiedades mecánicas de la aleación AA6060 procesada por ECAE(CENIM, 2011) Pérez Ruiz, Iván; Luis Pérez, Carmelo; Luri Irigoyen, Rodrigo; León Iriarte, Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaEn el presente trabajo se ha realizado un estudio de la modificación de las propiedades mecánicas de la aleación de aluminio AA6060 F, al ser deformada mediante deformación plástica severa empleando el proceso de extrusión en canal angular (ECAE). Asimismo, se ha efectuado un estudio del efecto del envejecimiento artificial sobre la modificación de dichas propiedades mecánicas. Para ello, se han realizado tratamientos térmicos a diferentes temperaturas y tiempos de permanencia, efectuando mediciones de dureza, ensayos de tracción, ensayos con péndulo Charpy y técnicas de revelado metalográfico, para conocer los comportamientos mecánicos y el estado del material. Existe un elevado número de publicaciones, que han analizado el efecto de tratamientos térmicos de envejecimiento en aleaciones de la serie 6000. Sin embargo, la aleación AA6060 no ha sido tan ampliamente estudiada. Por ello, en este trabajo se parte de una aleación comercial AA6060 en estado de bruto de colada, lo cual no ha sido estudiado hasta la fecha.Publication Open Access Analysis of fatigue and wear behaviour in ultrafine grained connecting rods(MDPI, 2017) Luri Irigoyen, Rodrigo; Luis Pérez, Carmelo; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaOver the last few years there has been an increasing interest in the study and development of processes that make it possible to obtain ultra-fine grained materials. Although there exists a large number of published works related to the improvement of the mechanical properties in these materials, there are only a few studies that analyse their in-service behaviour (fatigue and wear). In order to bridge the gap, in this present work, the fatigue and wear results obtained for connecting rods manufactured by using two different aluminium alloys (AA5754 and AA5083) previously deformed by severe plastic deformation (SPD), using Equal Channel Angular Pressing (ECAP), in order to obtain the ultrafine grain size in the processed materials are shown. For both aluminium alloys, two initial states were studied: annealed and ECAPed. The connecting rods were manufactured from the previously processed materials by using isothermal forging. Fatigue and wear experiments were carried out in order to characterize the in-service behaviour of the components. A comparative study of the results was made for both initial states of the materials. Furthermore, Finite Element Modelling (FEM) simulations were used in order to compare experimental results with those obtained from simulations. In addition, dimensional wear coefficients were found for each of the aluminium alloys and initial deformation states. This research work aims to progress the knowledge of the behaviour of components manufactured from ultrafine grain materials.Publication Open Access Analysis on the manufacturing of an AA5083 straight blade previously ECAE processed(Hindawi, 2013) Salcedo Pérez, Daniel; Luis Pérez, Carmelo; Puertas Arbizu, Ignacio; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaOver these past few years, there have been a large number of technical papers published related to the problem of improving the mechanical properties of materials obtained through severe plastic deformation. Nevertheless, the number of technical papers dealing with improvement in the mechanical properties of mechanical components manufactured from submicrometric grain size material has not been so proficient. Therefore, in this present research work, a straight blade has been manufactured starting from AA-5083 previously processed by ECAE twice (N2) with route C.This material will be manipulated so as to be isothermally forged at different temperature values.This present research work shows the results that are inherent in an improvement in themechanical properties and the microstructure achieved in the thus obtained components, compared with the starting material. In addition, the optimum forging temperature to achieve these components will be determined. As shown in this research work, it is possible to obtain submicrometric grain size mechanical components with a higher mechanical strength than those obtained in nonultrafine grained materials. The originality of this research work lies in the manufacturing of actual mechanical components from ECAE processed material and the analysis of their properties.Publication Open Access Analytical modelling of energy density and optimization of the EDM machining parameters of Inconel 600(MDPI, 2017) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaIn this present research work, a new modelling of energy density in EDM (Electrical Discharge Machining) is proposed. Energy density can be defined as the amount of energy needed to get a unit volume of material removed, and for its modelling, the whole EDM process has been taken into account. This new definition lets us quantify the energy density that is being absorbed by the workpiece and the electrode. Results are compared to those obtained by die sinking EDM in an Inconel ®600 alloy using Cu-C electrodes. Currently, this material is of great interest for industrial applications in the nuclear, aeronautical and chemical sectors, due to their combinations of good mechanical properties, corrosion resistance and extreme hardness at very high temperatures. The experimental results confirm that the use of negative polarity leads to a higher material removal rate, higher electrode wear and higher surface roughness. Moreover, the optimal condition to obtain a maximum MRR (Material Removal Rate) of 30.49 mm3/min was: 8 A, 100 µs and 0.6, respectively, for the current intensity, pulse time and duty cycle.Publication Open Access Auxiliary consumption: a necessary energy that affects thermoelectric generation(Elsevier, 2018) Aranguren Garacochea, Patricia; Araiz Vega, Miguel; Astrain Ulibarrena, David; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaWaste heat recovery can apply to a wide range of applications, from transportation, or industries to domestic appliances. Thermoelectric generation technology applied to those cases could produce electrical energy and thus improve their efficiency. A validated computational methodology, which simulates the behavior of any thermoelectric generator and calculates the energy consumption of the auxiliary equipment involved, has been used to determine the potential of waste heat harvesting. The usable energy, the net energy, generated has to be maximized, not only the thermoelectric generation has to be maximized, but also the consumption of the auxiliary equipment has to be minimized, or if possible eliminated. Heat exchangers with a liquid as the heat carrier procure high thermoelectric generations, as their thermal resistances are very low, nevertheless when the consumption of their auxiliary consumption is borne in mind, their use is not that promising. The optimal thermoelectric energy obtained from the flue gases of a real industry using these dissipation systems is 119 MWh/year, while the maximum net energy is 73 MWh/year due to the consumption of the auxiliary equipment. The latest scenario does not only represent a 40% reduction from the optimal thermoelectric generation but also a different optimal working point. The complete elimination of the auxiliary equipment using novel biphasic thermosyphons with free convection at the same application produces a net energy of 128 MWh/year. This novel dissipation technology presents an increase on the thermoelectric generation due to its low thermal resistances, but above all due to the elimination of the auxiliary consumption.Publication Open Access Caracterización de escorias metalúrgicas procedentes de yacimientos arqueológicos de Navarra (siglos II a.C.- IV d.C.)(Consejo Superior de Investigaciones Científicas (CSIC), 2013) Ros Latienda, L.; Fernández Carrasquilla, Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaDesde la Sección de Arqueología del Gobierno de Navarra llegó la propuesta de caracterizar una serie de piezas comprendidas entre el siglo II a.C. y el siglo IV d.C. procedentes de yacimientos arqueológicos de esta provincia con objeto de obtener datos relacionados con la tecnología que las produjo y poder comparar el grado de desarrollo técnico de diferentes épocas y lugares. Interesaba el estudio de estas piezas desde el punto de vista metalúrgico, habiendo entre ellas mayoritariamente escorias metalúrgicas, restos de piezas fabricadas y restos minerales utilizados en la obtención de diversos metales. Además de proceder a su análisis químico mediante técnica de plasma acoplado inductivamente (ICP), se estudiaron seis muestras mediante microscopía óptica, electrónica de barrido y microanálisis por energía dispersiva de rayos X (EDAX) que reveló la composición de zonas amplias de las escorias y finalmente se completó el estudio determinando las fases presentes mediante difracción de rayos X.Publication Open Access Characterization of two iron bullets from the royal ammunition factory of Eugi (Spain)(Technical Faculty, University of Belgrade, 2018) Zalakain Iriazabal, Iñaki; Berlanga Labari, Carlos; Álvarez Vega, Lucas; Rivero Fuente, Pedro J.; Valencia Monreal, Javier; Rodríguez Trías, Rafael; Mekanika, Energetika eta Materialen Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería Mecánica, Energética y de MaterialesIn this work, a comparative analysis of two iron bullets found in The Royal Ammunition Factory of Eugi in Navarra (Spain) was performed. Both bullets presented a spherical shape with a relatively good state of preservation, belonging to the last years of the factory production (1766-1850). Several techniques such as microhardness, X-ray fluorescence (XRF), light (LM) and scanning electron microscopy (SEM), optical mission spectroscopy (OES) and energy dispersive X-ray spectroscopy (EDX) analysis were used in order to identify the manufacturing process of the two bullets. The analyses of the microstructures carried out by LM and SEM showed that one bullet was composed of white cast iron with a pearlitic matrix, steadite and graphite; while the other was composed of grey cast iron with a pearlitic matrix, graphite and a low amount of steadite. The chemical analysis of the bullets carried out by OES indicated significant differences in the amount of silicon and phosphorous. The variation in silicon content could suggest that the foundry temperature under oxidizing environment varied during the casting. The SEM and EDX analyses showed both bullets had manganese sulphide inclusions but only one of the bullets exhibited titanium and vanadium inclusions. The microhardness analyses carried out revealed Vickers hardness differences along the diameter. This variation could be explained by the differences in cooling rate along the diameter. Based on the physical characteristics of the bullets and on the obtained results, it can be concluded that one of the bullets could have been used as a grapeshot projectile and the other one as a bullet for ribauldequins. In addition, calcined ore and slag found in this factory were also analysed. The variation found in their chemical composition corroborated that the foundry temperature employed during the manufacturing process was low, the slag being enriched in Si, Al and Mn elements.Publication Open Access CO2 emissions reduction and energy efficiency improvements in paper making drying process control by sensors(MDPI, 2017) Calvo Herrero, Luis; Domingo, Rosario; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThe drying process of paper has many production parameters that can influence both the energy consumed and the characteristics of paper produced. It was found that most of the previous studies conducted on this process assume that the conditions of the facilities are always appropriate. The control of the variables associated with air circulating inside the drying hood is essential to obtain a paper with adequate quality and obtain low ratios of energy consumption and CO2 emissions. This article proposes a new indirect method based on the study of the enthalpy of the airflows inside the production hall and thermographic images that helps to analyze the maintenance state of the enclosure hood drying section in a general process, whereby it can also estimate the emissions and energy losses. The combined use of sensors and equipment has helped to identify energy losses and potential savings in CO2 emissions. The developed method is applied to a paper manufacturing plant that has ratios of energy consumption and CO2 emissions very close to the product benchmark set by the European Authorities. The study corroborates that it can be identified as a significant energy loss in paper making drying process. Analyzing facilities that are in apparently good maintenance conditions, leaks are evident. These energy losses are very significant compared with the theoretical energy consumption, and it can affect the paper moisture profile.Publication Open Access Compound Petri nets and alternatives aggregation Petri nets: two formalisms for decision-making support(SAGE, 2016) Latorre Biel, Juan Ignacio; Jiménez Macías, Emilio; Pérez de la Parte, Mercedes; Sáenz Díez, Juan Carlos; Martínez Cámara, Eduardo; Blanco Fernández, Julio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaDecision-making in technological systems, such as communication networks, manufacturing facilities and supply chains, constitutes a common requirement able to lead companies galore to success or failure. This article presents a decisionmaking methodology, where the feasible structural configurations to be analysed are chosen heuristically in the frame of a single optimization problem. For stating the optimization problem and solving it efficiently, appropriate formalisms would be used. Compound Petri nets, a particular kind of parametric Petri nets, and alternatives aggregation Petri nets, are two Petri net–based formalisms able to integrate in the same model different alternative structural configurations. Moreover, even having different characteristics that might make them useful for different applications, both formalisms present common features, such as including a set of exclusive entities and the possibility of developing compact Petri net models, by the removal of redundant information. This article is also focused on the transformation algorithm between compound Petri nets and alternatives aggregation Petri nets. This algorithm is devoted to transform a model described by one of the formalisms into an equivalent model, that is, with the same behaviour, represented using the other formalism. Finally, several application examples are given for illustrating the steps of the transformation algorithm.Publication Open Access Computational and experimental study of a complete heat dissipation system using water as heat carrier placed on a thermoelectric generator(Elsevier, 2014) Aranguren Garacochea, Patricia; Astrain Ulibarrena, David; Pérez Artieda, Miren Gurutze; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThe heat dissipation systems which have liquids as heat carriers outperform conventional dissipation systems at thermoelectric generators (TEGs). However, new elements need to be introduced such as pumps, secondary heat exchangers and piping. A predictive computational model of a dissipation system involving refrigerant liquids has been implemented. The accuracy of the model is 93 % for all its outputs: the total thermal resistance, the hydraulic losses and the auxiliary power consumption. The validation of the model has been done with a prototype mainly composed by a multi-channel heat exchanger, a fan-coil, a pump and several sensors: temperature, pressure and flow meters. A study on the influence of the water and the air mass flow over the total thermal resistance has been conducted. The total resistance dependence on the air mass flow shows the importance of including the secondary heat exchanger into the thermal and hydraulic calculations. The smallest resistance does not always obtain the highest net power generation, the high demanding power of the auxiliary equipment needed to obtain this resistance influences negatively on the net power generation. Among the experimental points, the optimum scenario obtains a 40 % additional power generation with respect to the smallest resistance point.Publication Open Access Computational simulation of scleral buckling surgery for rhegmatogenous retinal detachment: on the effect of the band size on the myopization(Hindawi, 2016) Lanchares, Elena; Buey, María A. del; Cristóbal, José A.; Calvo, Begoña; Ascaso, Francisco J.; Malvè, Mauro; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaA finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied.The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia.The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5mm bandwidth, respectively.Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery.Publication Open Access Computational study on the thermal influence of the components of a thermoelectric ice maker on the ice production(Springer US, 2012) Rodríguez García, Antonio; Astrain Ulibarrena, David; Martínez Echeverri, Álvaro; González Vian, José; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThe main objective of this paper is to study the thermal resistances of two components of a thermoelectric ice maker installed in a no-frost refrigerator, in order to optimize the ice production. This study is conducted via a computational model developed by the Thermal and Fluids Research Group from Public University of Navarre, explained and validated in previous papers. Firstly, three dissipaters with different space between fins are simulated using Computational Fluid Dynamics Fluent to study their influence on both the ice production and the performance of the refrigerator. The computational model predicts a maximum production of 2.82 kg/day of ice with less than 7 W of extra electric power consumption, though these values depend to a great extent on the cooling and freezing power of the refrigerator. Secondly, this work focuses on reducing the size of the components in order to save raw material and reduce the cost of the device. The computational model predicts that the last design produces 2.42 kg/day of ice, saves 65 % of raw material and reduces to the half the expenses assigned to the thermoelectric modules.Publication Open Access Control of discrete event systems by means of discrete optimization and disjunctive colored PNs: application to manufacturing facilities(Hindawi, 2014) Latorre Biel, Juan Ignacio; Jiménez Macías, Emilio; Pérez de la Parte, Mercedes; Blanco Fernández, Julio; Martínez Cámara, Eduardo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaArtificial intelligence methodologies, as the core of discrete control and decision support systems, have been extensively applied in the industrial production sector. The resulting tools produce excellent results in certain cases; however, the NP-hard nature of many discrete control or decision making problems in the manufacturing area may require unaffordable computational resources, constrained by the limited available time required to obtain a solution. With the purpose of improving the efficiency of a control methodology for discrete systems, based on a simulation-based optimization and the Petri net (PN) model of the real discrete event dynamic system (DEDS), this paper presents a strategy, where a transformation applied to the model allows removing the redundant information to obtain a smaller model containing the same useful information. As a result, faster discrete optimizations can be implemented.This methodology is based on the use of a formalism belonging to the paradigmof thePNfor describingDEDS, the disjunctive colored PN. Furthermore, the metaheuristic of genetic algorithms is applied to the search of the best solutions in the solution space. As an illustration of the methodology proposal, its performance is compared with the classic approach on a case study, obtaining faster the optimal solution.Publication Open Access Coupled biomechanical response of the cornea assessed by non-contact tonometry. A simulation study(Public Library of Science, 2015) Ariza Gracia, Miguel A.; Zurita Gabasa, Jesús; Piñero, David P.; Rodríguez Matas, José F.; Calvo, Begoña; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThe mechanical response of the cornea subjected to a non-contact air-jet tonometry diagnostic test represents an interplay between its geometry, the corneal material behavior and the loading. The objective is to study this interplay to better understand and interpret the results obtained with a non-contact tonometry test. A patient-specific finite element model of a healthy eye, accounting for the load free configuration, was used. The corneal tissue was modeled as an anisotropic hyperelastic material with two preferential directions. Three different sets of parameters within the human experimental range obtained from inflation tests were considered. The influence of the IOP was studied by considering four pressure levels (10–28 mmHg) whereas the influence of corneal thickness was studied by inducing a uniform variation (300–600 microns). A Computer Fluid Dynamics (CFD) air-jet simulation determined pressure loading exerted on the anterior corneal surface. The maximum apex displacement showed a linear variation with IOP for all materials examined. On the contrary, the maximum apex displacement followed a cubic relation with corneal thickness. In addition, a significant sensitivity of the apical displacement to the corneal stiffness was also obtained. Explanation to this behavior was found in the fact that the cornea experiences bending when subjected to an air-puff loading, causing the anterior surface to work in compression whereas the posterior surface works in tension. Hence, collagen fibers located at the anterior surface do not contribute to load bearing. Non-contact tonometry devices give useful information that could be misleading since the corneal deformation is the result of the interaction between the mechanical properties, IOP, and geometry. Therefore, a noncontact tonometry test is not sufficient to evaluate their individual contribution and a complete in-vivo characterization would require more than one test to independently determine the membrane and bending corneal behavior.Publication Open Access Dependencia de las propiedades mecánicas y de la composición química en la fundición de grafito esferoidal(CENIM, 2006) Gonzaga Cinco, R.; Fernández Carrasquilla, Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaCon este trabajo se pretende estudiar la composición química de cuatro escaleras de fundición dúctil para determinar la influencia de los diferentes elementos de aleación sobre la microestructura y las propiedades mecánicas. Las cuatro escaleras tienen las mismas dimensiones de 200 x 100 x 50 (mm). Para determinar cada una de las propiedades de las cuatro fundiciones, hemos considerado que las mismas han tenido diferente velocidad de enfriamiento, de lo que se deriva, que el tamaño de grano varía para cada uno de los casos. En este trabajo, se ha realizado un estudio de las diferentes microestructuras de las escaleras. Se ha considerado el análisis de la influencia del grosor sobre la dureza de cada probeta. No se ha empleado ningún tratamiento térmico. Se ha determinado la resistencia a la tracción y límite elástico. Se han realizado ensayos de Charpy y de mecánica de la fractura.Publication Open Access Design and mechanical properties analysis of AA5083 ultrafine grained cams(MDPI, 2017) Salcedo Pérez, Daniel; Luis Pérez, Carmelo; Luri Irigoyen, Rodrigo; Puertas Arbizu, Ignacio; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThis present research work deals with the development of ultrafine grained cams obtained from previously ECAP (Equal Channel Angular Pressing)-processed material and manufactured by isothermal forging. The design and the manufacturing of the dies required for the isothermal forging of the cams are shown. Optimization techniques based on the combination of design of experiments, finite element and finite volume simulations are employed to develop the dies. A comparison is made between the mechanical properties obtained with the cams manufactured from material with no previous deformation and with those from previously SPD (Severe Plastic Deformation)-processed material. In addition, a comparative study between the experimental results and those obtained from the simulations is carried out. It has been demonstrated that it is possible to obtain ultrafine grained cams with an increase of 10.3% in the microhardness mean value as compared to that obtained from material with no previous deformation.Publication Open Access Design, optimization, and mechanical property analysis of a submicrometric aluminium alloy connecting rod(Hindawi, 2015) Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Luis Pérez, Carmelo; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaUltrafine grained materials have a great deal of both scientific and technological interest because they allow outstanding properties to be obtained. An improvement in the mechanical strength and in the ductility and a better fatigue behaviour are properties to be expected with these materials. However, in spite of the great number of scientific publications that deals with the mechanical property improvement, the number of practical applications of these materials is scant. In this present research work, equal channel angular pressing (ECAP) is used as a severe plastic deformation process (SPD) to obtain billets which are subsequently isothermally forged to obtain a connecting rod with submicrometric grain size. The optimization of the design process is shown as well as the die design. The objective variables to be fulfilled are the correct filling of the die and the required force to obtain the part. Moreover, a comparison is also included between the mechanical properties thus obtained and those obtained with traditional methods. Moreover, optical and SEM micrographs are also included in this research work.Publication Open Access Design, simulation and manufacturing of a connecting rod from ultra-fine grained material and isothermal forging(Elsevier, 2016) Fuertes Bonel, Juan Pablo; Luis Pérez, Carmelo; Luri Irigoyen, Rodrigo; Salcedo Pérez, Daniel; León Iriarte, Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaIn this research work, a study on the mechanical properties of isothermal forging for connecting rods is made from previously ECAP (Equal Channel Angular Pressing)-processed AA1050 and AA5083 aluminium alloys. This severe plastic deformation (SPD) process is used in order to achieve a starting material with a submicrometric structure, thus improving the mechanical properties of the part. In this study, the design and the experimentation process is shown, where this involves the design stage by finite element simulations, the experimental tests and the use of metallographic techniques for the required properties to be analysed. Itis observed thatthere is an improvementin the mechanical properties when the starting material is ECAP-processed before carrying out the isothermal forging. This improvement consists in an increase of 20% in the hardness of the final connecting rod which also possesses a microstructure grain size of 500 nm. To come to these conclusions,the results obtained with the connecting rods manufactured by isothermal forging from previously ECAP-processed material are compared with those conventionally manufactured. Therefore,the feasibility and the advantages ofthe industrialmanufacturing ofmechanical components by isothermal forging from ECAP-processed material are demonstrated here as mechanical properties are achieved, as well as a better flow of the material and at a lower forging temperature. In the existing bibliography, there are no research works dealing with the manufacturing of connecting rods from ultra-fine grained material and that is the reason why this present study is considered to be of scientific and technological interest, and therefore, it may be considered to be at the frontline of current knowledge.Publication Open Access Determination of the symbolic base inertial parameters of planar mechanisms(Elsevier, 2017) Iriarte Goñi, Xabier; Ros Ganuza, Javier; Mata, Vicente; Aginaga García, Jokin; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen IngeniaritzaThe inertial information of a planar mechanical system is characterised using 4 inertial parameters per solid. Due to the kinematic constraints, this parametrisation turns out be redundant. In order to reduce the computational cost of the model and make it possible to estimate its inertial parameters, the model is usually written in terms of a minimum set of inertial parameters called base inertial parameters. These parameters completely determine the dynamics of motion (kinetics) of a mechanism and, since their contributions are independent to each other, their actual values can be estimated experimentally. The base inertial parameters expressions can be written as a linear combination of the inertial parameters and determining their symbolic expressions provides a deeper insight into their physical meaning. This paper presents a new algorithm to determine the symbolic expressions of the base inertial parameters of planar mechanisms. The approach is based on a very well known numerical method to obtain the base inertial parameters and on the fact that these parameters belong to a class of functions that lets us search for symbolic expressions matching with them. Since the symbolic expressions are a function of the geometric constants of the system, the presented algorithm constitutes a very valuable tool in design optimisation and it is also very interesting in dynamic parameter estimation, model reduction and other fields.