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To define inspection intervals that ensure the continuous and safe operation of a damage-tolerant component, such as a railway axle, a reliable estimation of its fatigue crack growth life is required. Due to the uncertainties involved in the fatigue process, inspections have to be devised not only considering the uncertainties in the performance of the inspection technique, but also based on a probabilistic lifespan prediction. From this premise, this paper presents a procedure for determination of inspection intervals that uses a conservative fatigue crack growth life estimation based on the lifespan probability distribution. A practical example to illustrate the reliability-based inspection planning methodology in a railway axle under random bending loading is given. The inspection intervals are further assessed in terms of total probability of detecting cracks in successive inspections, taking into account the probability of detection curve of the non-destructive testing technique. The procedure developed provides recommendation for the definition of inspection intervals and associated inspection techniques.

The propagation of uncertainty in fatigue crack growth life aims to find the effects of the process variables randomness in the fatigue lifespan. This treatment of the crack growth process commonly provides the probability distribution of the fatigue lifespan which is essential to predict the performance of a component concerning risk assessment and management. This paper presents a procedure that uses the first four moments of the fatigue crack growth life predicted by the full second-order approach to fit the parameters of a probability distribution based on the Pearson distribution family. A numerical example to illustrate the fatigue crack growth in a railway axle under random bending loading is given. The probabilistic results are compared with Monte Carlo simulations to check the goodness of the first four moments predicted and the quality of the probability density function constructed. The probabilistic description of fatigue lifespan provided can be used in ensuring the continued safe operation of a damage tolerant component.

Different options that rely on fracture mechanics are currently used in engineering during the design and assessment of components. One of the most important aspects is the time taken for a crack to extend to its critical size. If this time is known and it is sufficiently large, a design concept based on inspection intervals can be applied in a viable way, as is it the case of a railway axle component. To define inspection intervals that ensure the continuous and safe operation of a damage-tolerant railway axle, a reliable estimation of its fatigue crack growth life is required. Due to the uncertainties involved in the fatigue process, inspections must be devised not only considering the uncertainties in the performance of the inspection technique, but also based on a probabilistic lifespan prediction. From this premise, this paper presents a procedure for determination of inspection intervals that uses a conservative fatigue crack growth life estimation based on the lifespan probability distribution. A practical example to illustrate the reliability-based inspection planning methodology in a railway axle under random bending loading is given. The inspection intervals are further assessed in terms of overall probability of detecting cracks in successive inspections and in terms of probability of failure, considering the probability of detection curve of the non-destructive testing technique. The procedure developed provides recommendation for the definition of inspection intervals and associated inspection techniques.

Uncertainty propagation of fatigue crack growth life commonly aims to provide the probability distribution of the lifespan needed for probabilistic damage tolerance analysis and for structural integrity assessment. This paper presents a novel methodology for efficiently estimating the parameters of the probability distribution of fatigue lifespan considering the Pearson distribution family. First, the full second-order approach for expected value and variance prediction of probabilistic fatigue crack growth life is extended to predict higher order statistical moments of the underlying distribution. That is, the expected value (first raw moment) and the variance (second central moment) equations are complemented with the probabilistic formulations for the skewness and for the kurtosis (third and fourth central standardized moments, respectively). Then, from these moments, the Pearson distribution type is automatically determined. Finally, the parameters of the particular Pearson distribution type are estimated making the statistical moments of the constructed lifespan distribution match the first four prescribed moments predicted by the probabilistic equations. The validity of the proposed method is verified by a numerical example regarding the fatigue crack growth in a railway axle under random bending loading. It is proven that the probability density function of the lifespan is properly derived by the methodology, without knowing or assuming the output probability distribution beforehand. The methodology presented enables an efficient and an accurate quantification of the lifespan uncertainties via its probabilistic distribution. This probabilistic description of fatigue crack growth life can be subsequently used in reliability studies or in damage tolerance assessment.

Current european standards for axle calculations (EN 13103 and EN 13104) are based on an analytical method applying flexural beam principle for critical sections selected by the designer. The method bases on works performed in the 1960s that were introduced to different international reports and recommendations before being adopted by the mentioned european standards. The present procedures for design, production and maintenance of axles lead to reliable products, as shown by the accumulated experience along the last decades. These methods are widely accepted and applied to axle designs in common usage. However, in order to look for optimized products, more accurate modelling techniques like the finite element analysis (FEA) should be adopted, especially for complex structures like powered axles. The characteristics of the finite element models to be applied to railway axles have been analysed in terms of element definition, convergence analysis, boundary conditions, etc. Parametric analyses have been performed to assess the applicability of the models. The numerical models generated have been validated through the comparison with experimental results coming from full scale fatigue tests. Finally, a methodology to design axles using modelling tools as a complement to current european norms is proposed looking for a compromise between the computational effort and the results obtained.

La imposibilidad de encontrar una unica vision e interpretacion del pasado compartida por toda la sociedad esconde distintas maneras de mirar al ayer; y las distintas y variadas miradas al ayer estan en el origen de la configuracion de los distintos sentimientos de pertenencia, de las distintas identidades nacionales. Este es el punto de partida de este trabajo que analiza las memorias de las cuatro culturas politicas mas representativas del escenario vasco durante la Transicion, es decir, el nacionalismo historico (representado por Euzko Alderdi Jeltzalea-Partido Nacionalista Vasco), la izquierda estatal (representada por el Partido Socialista de Euskadi-Partido Socialista Obrero Espanol), el centro derecha espanol (representado por Union de Centro Democratico) y la izquierda abertzale (representada por las coaliciones Euskadiko Ezkerra y Herri Batasuna). La identificacion de los referentes identitarios clave de estas cuatro culturas politicas y la explicacion de las razones de su referencialidad en ese contexto concreto es lo que da forma a los cuatro principales capitulos del libro. Los dos capitulos introductorios recogen la perspectiva de analisis y la propia definicion del objeto de estudio, que responden a los planteamientos mas actuales de la disciplina historica. La memoria, uno de los campos fundamentales de investigacion en la mas reciente historiografia, es el eje en torno al cual giran los distintos capitulos de este libro que espera aportar una nueva panoramica del periodo estudiado y confia en contribuir a completar la produccion historiografica de la Transicion en el Pais Vasco.

The NASGRO crack growth equation for fatigue life estimation is ordinarily used in its deterministic standard form. This paper presents a new probabilistic formulation for fatigue crack propagation based on the NASGRO equation providing a stochastic approach for predicting statistical moments of fatigue lifetime. The methodology approximates the expected value and variance, of the output random variable fatigue lifetime ( N ). These moments are obtained from the approximation via the Taylor series up to the quadratic terms, full second-order, of the NASGRO equation with respect to the random input variables taken into account. The validity of the proposed method is verified by two numerical examples regarding the fatigue crack growth in a railway axle under two different random loading conditions. The first one applies the probabilistic formulations under a random bending loading. The second one takes into account a service loading spectrum acting on the axle subjected to a random load. Then, the statistical moments calculated are checked by comparison with Monte Carlo simulations. The probabilistic model developed enables an efficient estimation of statistical moments, providing accurate probabilistic results that can be used in design stages, reliability studies or in damage tolerance assessment.

La sociedad vasca del siglo XXI, plural y diversa en cuanto a sentimientos de pertenencia, ha sido el punto de partida de esta tesis doctoral, que ha tenido como objeto de análisis las memorias de las cuatro culturas políticas más representativas de escenario vasco durante la Transición, es decir, el nacionalismo histórico (representado por Euzko Alder di Jeltzalea-Partido Nacionalista Vasco), la izquierda estatal (representada por el Partido Socialista de Euskadi-Partido Socialista Obrero Es...

The debate on the political signi cance of the fueros (Basque historical law code) did not end in the eighteenth century with Manuel de Larramendi, who was con-sidered a predecessor in the study of Basque foralidad. The fueros continue to be interpreted in di erent manners and have been the subject of some of the most relevant contemporary political debates. This article presents and compares the di erent ways in which the fueros were re-thought by two political parties in the Basque Country during the Spanish transition to democracy. Said parties were EAJ-PNV (Euzko Alderdi Jeltzalea – Basque Nationalist Party) and UCD (Union of the Democratic Centre), which saw the fueros as the cornerstone of their di e- rent identitarian discourses. El debate sobre el significado político de los fueros no terminó en el siglo XVIII con Manuel de Larramendi, considerado un precursor de la foralidad vasca. Los fueros siguen siendo objeto de interpretaciones variadas y han protagonizado algunos de los debates políticos más relevantes de la contemporaneidad. Este artículo presenta y compara las distintas recreaciones que de los fueros hicieron dos partidos políticos durante la Transición en el País Vasco: nos referimos a EAJ-PNV (Euzko Alderdi Jeltzalea – Partido Nacionalista Vasco) y UCD (Unión de Centro Democrático) para quienes la foralidad fue piedra angular de sus respectivos y diferentes discursos identitarios. Foruen esanahi politikoari buruzko eztabaida ez zen XVIII. mendean bukatu Ma- nuel Larramendirekin, euskal foralitatearen aitzindari gisa aintzakotzat hartuare- kin. Foruei buruzko askotariko interpretazioak egiten dira oraindik eta gaur egun- go eztabaida politiko garrantzitsuenetako batzuetako protagonista izan dira foruak. Artikulu honek Euskal Herrian Trantsizio garaian bi alderdi politikok, EAJ-PNV-k (Euzko Alderdi Jeltzalea-Partido Nacionalista Vasco) eta UCD-k (Unión de Cen-tro Democrático), garatutako foruen berregiteak aurkeztu eta konparatzen ditu. Bi alderdi hauen kasuan foralitatea beren diskurtso identitarioen giltzarri izan zen.

[EUS] EAEko eta Finlandiako hezkuntza-sistemen alderaketan datzan GrAL honek Hezkuntza Gonbaratua izan du ardatz. Bertan, bi lurralde hauek hezkuntza inklusiboaren trataerari eskainitako erantzuna alderatu izan da. Ikerketa lana da hau eta analisi sistematikoaren bitartez, hezkuntza inklusiboaren inguruko elementu batzuk aztertu izan dira. Helburua bi herrialde hauen aniztasunaren trataera konparatzea eta ezagutzea zen eta horren bitartez, hezkuntza inklusiboaren ulermenean ezberdintasunak azaleratu izan dira: inklusioarekiko jarrera uzkurra izanik Finlandia integrazioan ardazten den bitartean, EAEn inklusioarekiko bidean aurrerapausoak nabari dira. Hala ere, aldaketa beharra sumatzen da bai hemengo zein Finlandiako legedian. Hori horrela, giza-eskubidetzat dugun inklusioa lortzeko bidean jarraituz gero, ikasleei eskolan ere errealitatearen aniztasunean hezteko aukera eskainiko diegu. [ES] Este TFG, que se centra la comparación de los sistemas educativos de la CAV y Finlandia, ha tenido como eje la Educación Comparada. En él se ha comparado la respuesta que estos dos territorios ofrecen al tratamiento de la educación inclusiva. Éste es un trabajo de investigación que, mediante un análisis sistemático, ha analizado algunos elementos relativos a la inclusión en el ámbito educativo. El objetivo era comparar y conocer el tratamiento de la diversidad en estos dos lugares y, mediante ello, surgieron varias diferencias en la comprensión del mismo: mientras que Finlandia presenta una actitud reacia hacia la inclusión y se centra en la integración, la CAV muestra un avance hacia el proceso de inclusión. Sin embargo, la necesidad de cambio no sólo se percibe en la legislación finlandesa, sino también en la vasca. De ese modo, siguiendo el camino para conseguir la inclusión como derecho humano, ofreceremos a los alumnos la oportunidad de poder ser educados, también en la escuela, en la diversidad propia de la realidad social. [EN] This FDP based on the comparison between finnish and basque educational systems has been focused on Comparative Education. Here it has been compared the response that these two territories offer to the treatment of inclusive education. This is a research work and through a systematic analysis, some elements of inclusive education have been analysed. The aim was to compare and know inclusive education treatment in these places and, through this dissertation, some differences appeared regarding inclusive education understanding: while Finland, due to its resistant attitude towards inclusion, is focused on integration, the Basque Country shows an improvement in the process of inclusion. However, legislation change is not only necessary in Finland, but also in the Basque Country. In that way, following the path towards inclusion as a human right, students will have, in school as well, the opportunity to be educated in the diversity of social reality.

The acoustic reductions achieved with the current damping solutions for railway wheels that appear in the state of the art were obtained with different railway wheel designs, under different measurement scenarios (laboratory and on track), under different testing conditions, making it impossible to compare these damping solutions in a straightforward manner. The aim of this paper is to analyse, measure and estimate the behaviour of damping solutions installed on the same railway wheel and under the same testing conditions. Experimental measurements were carried out in the laboratory on wheels that are currently in use in metro lines. Damping solutions that were evaluated are ring damper, friction damper and sandwich-type constrained layer damper. Results show that ring and friction dampers are dependent on the applied preload and that they can only dissipate energy at high frequencies. Sandwich-type constrained layer dampers are the only damping solution that can add damping at low frequencies, but it is essential that they be properly designed in order to significantly increase the final wheel damping.

Las dificultades para articular un discurso rotundo y compartido sobre la definición de la identidad nacional y el modelo de vertebración territorial de la nueva España democrática caracterizaron al proceso de Transición. El País Vasco no fue ajeno a este debate. La existencia de un sistema de partidos políticos peculiar, que cuenta con varias líneas de fractura, como la clásica entre izquierda y derecha, a la que se añade la línea de tensión entre partidos nacionalistas/abertzales y estatalistas/españolistas, no hace sino multiplicar las opciones de definición identitaria. En este artículo nos centraremos en la idea que de España articularon UCD (Unión de Centro Democrático) y AP (Alianza Popular) en el País Vasco durante el proceso constituyente.

This paper presents a procedure for predicting the damping added to a railway wheel when sandwich-type dampers are installed. Although there are different ways to reduce the noise generated by a railway wheel, most devices are based on the mechanism of increasing wheel damping. This is why modal damping ratios are a clear indicator of the efficiency of the damping device and essential when a vibro-acoustic study of a railway wheel is carried out. Based on a number of output variables extracted from the wheel and damper models, the strategy explained herein provides the final damping ratios of the damped wheel. Several different configurations are designed and experimentally tested. Theoretical and experimental results agree adequately, and it is demonstrated that this procedure is a good tool for qualitative comparison between different solutions in the design stages.

Current European standards for axle calculations (EN 13103 and EN 13104) are based on an analytical method applying flexural beam principle for critical sections selected by the designer. The method bases on works performed in the 1960s that were introduced to different international reports and recommendations before being adopted by the mentioned European standards. The present procedures for design, production and maintenance of axles lead to reliable products, as shown by the accumulated experience along the last decades. These methods are widely accepted and applied to axle designs in common usage. However, in order to look for optimized products, more accurate modelling techniques like finite element analysis should be adopted, especially for complex structures like powered axles. The characteristics of the finite element models to be applied to railway axles have been analyzed. The numerical models generated have been validated through the comparison with experimental results coming from full scale fatigue. Finally, a methodology to design axles using modelling tools as a complement to current European norms is proposed looking for a compromise between the computational effort and the attained results.

An integrated, multiphysics numerical model has been developed through the joint efforts of the University of Oxford (UK), University of Bremen (Germany) and Inasmet (Spain) to simulate the spray forming process. The integrated model consisted of four sub-models: (1) an atomization model simulating the fragmentation of a continuous liquid metal stream into droplet spray during gas atomization; (2) a droplet spray model simulating the droplet spray mass and enthalpy evolution in the gas flow field prior to deposition; (3) a droplet deposition model simulating droplet deposition, splashing and re-deposition behavior and the resulting preform shape and heat flow; and (4) a porosity model simulating the porosity distribution inside a spray formed ring preform. The model has been validated against experiments of the spray forming of large diameter IN718 Ni superalloy rings. The modelled preform shape, surface temperature and final porosity distribution showed good agreement with experimental measurements. (c) 2007 Elsevier B.V. All rights reserved.

This paper presents a theoretical study of the parameters that influence sandwich-type constrained layer damper design. Although there are different ways to reduce the noise generated by a railway wheel, most devices are based on the mechanism of increasing wheel damping. Sandwich-type constrained layer dampers can be designed so their resonance frequencies coincide with the wheel’s resonant vibration frequencies, and thus the damping effect can be concentrated within the frequency ranges of interest. However, the influence of design parameters has not yet been studied. Based on a number of numerical simulations, this paper provides recommendations for the design stages of sandwich-type constrained layer dampers.

Symmetric forms of systems of equations describing physical phenomena present exceptional desirable properties such as symmetric coefficient matrices, well posedness of the Cauchy initial value problem, finite wave propagation speeds and a link to nonlinear stability principles. Therefore, they should be used when possible to design better numerical methods. In this paper such symmetric forms are reviewed for various models of fluid flow, and a hierarchy of generalized entropy functions is presented. Standard concepts are extended to the diffusive terms.