Diseño de modelo a escala de una grúa torre

El objetivo del presente proyecto es el diseño de una grúa torre a escala reducida empleando como elementos para su estructura exclusivamente palos de helado, con una altura útil de 0,87 m y una longitud de pluma de 0,7m. Su carga máxima en el extremo es de 10 N. Además el diseño de la misma es modular. La metodología utilizada para el dimensionamiento de la grúa distingue dos partes. Por un lado el dimensionamiento y cálculo de la estructura de la grúa con todas las hipótesis de carga necesarias y los coeficientes de seguridad que indica la normativa de aparatos de elevación UNE 58132-2:2000. Por otro lado la selección de todos los accionamientos y elementos que permiten a la grúa darle la función de aparato de elevación. Con el fin de realizar un diseño correcto se han utilizado distintas herramientas CAE y CAD para dimensionar la grúa y sus elementos. El análisis estructural se realizó mediante el software SAP2000 V10, mientras que para los planos de fabricación y montaje se empleó AutoCAD 2002. Esta grúa ha obtenido el 1er premio en 2009 del 1er Concurso Nacional de Grúas con Palos de Helado”, organizado por la Delegación de Estudiantes de la Universidad Carlos III de Madrid, en la categoría Funcionalidad y Estética.Ingeniería Industria

Simulation rapide - Correction de forme assistée après usinage

Distortions after machining of large aluminium forgings are a recurrent problem for the aeronautical industry. These deviations from design geometry are caused by the presence of residual stresses, which are developed along the manufacturing chain, especially after the heat treatment of quenching. To restore the nominal geometry, a series of highly manual and time-consuming reshaping operations need to be carried out. This work is concerned with the development of efficient computer simulation tools to assist operators in bending straightening, which is one of the most common reshaping operations. To this end, we develop a Finite Element simulation model which is representative of the manufacturing chain, including quenching, machining, and reshaping, which allows to predict residual stresses and distortions in thick-walled aluminium forgings. The model is validated against experimental data found in the literature. Then, we introduce the concept of reshaping diagrams, a tool that allows selecting a nearly optimal bending load to minimize distortion. We show that the reshaping diagram needs not to account for the residual stress field, as its only effect is to shift the reshaping diagram by some offset. Therefore, the overall behaviour including a realistic 3D residual stress field in a forged part can be retrieved by shifting the residual stress-free reshaping diagram by the appropriate offset. Finally, we propose a strategy to identify the offset on-the-fly during the reshaping operation using simple force-displacement measures. Then we explore the use of novel numerical techniques, especially Model Order Reduction (MOR), with a two-fold purpose: i) to speed-up the computation of reshaping diagrams; and ii) to account for various process parameters, such as initial distortion or the reshaping setup. To this end, we rely on the Sparse Subspace Learning method (SSL), a non-intrusive MOR method that allows reconstructing the solution space directly from the outputs of the Finite Element model. With the parametric solution at hand, the optimum reshaping configuration can be found in real time, to minimize distortion before launching the actual reshaping operation. Finally, we propose the first steps towards the extension of the above methodology, which combines reshaping diagrams and MOR methods, to a multi stage setting in which several shape correction operations take place sequentially.Les distorsions après usinage des grandes pièces forgées en aluminium sont un problème récurrent pour l'industrie aéronautique. Ces écarts par rapport à la géométrie de conception sont causés par la présence de contraintes résiduelles, qui se développent tout au long de la chaîne de fabrication, en particulier après le traitement thermique de la trempe. Pour rétablir la géométrie nominale, il faut procéder à une série d'opérations de remodelage très manuelles et très longues. Ce travail concerne le développement d'outils de simulation informatique efficaces pour aider les opérateurs à redresser par flexion, qui est l'une des opérations de déformation les plus courantes. À cette fin, nous développons un modèle de simulation par éléments finis représentatif de la chaîne de fabrication, y compris la trempe, l'usinage et le formage, qui permet de prédire les contraintes résiduelles et les déformations des pièces forgées en aluminium à paroi épaisse. Le modèle est validé par rapport à des données expérimentales trouvées dans la littérature. Ensuite, nous introduisons le concept de diagrammes de remodelage, un outil qui permet de sélectionner une charge de flexion presque optimale afin de minimiser la distorsion. Nous montrons que le diagramme de remodelage n'a pas besoin de tenir compte du champ de contrainte résiduel, car son seul effet est de décaler le diagramme de remodelage d’un certain décalage. Par conséquent, le comportement global incluant un champ de contrainte résiduelle réaliste en 3D dans une pièce forgée peut être récupéré en décalant le diagramme de remodelage sans contrainte résiduelle du décalage approprié. Enfin, nous proposons une stratégie permettant d'identifier le décalage à la volée pendant l'opération de remodelage en utilisant des mesures simples de force-déplacement. Nous explorons ensuite l'utilisation de nouvelles techniques numériques, en particulier la réduction de l'ordre du modèle (MOR), dans un double but : i) accélérer le calcul des diagrammes de mise en forme; et ii) prendre en compte divers paramètres du processus, tels que la distorsion initiale ou la configuration de la mise en forme. À cette fin, nous nous appuyons sur la méthode Sparse Subspace Learning (SSL), une méthode MOR non intrusive qui permet de reconstruire l'espace de solution directement à partir des sorties du modèle d'éléments finis. Avec la solution paramétrique à portée de main, la configuration de remodelage optimale peut être trouvée en temps réel, pour minimiser la distorsion avant de lancer l'opération de remodelage proprement dite. Enfin, nous proposons les premières étapes vers l'extension de la méthodologie ci-dessus, qui combine les diagrammes de remodelage et les méthodes MOR, à un cadre à plusieurs étapes dans lequel plusieurs opérations de correction de forme ont lieu de manière séquentielle

Reshaping of large aeronautical structural parts: a simplified simulation approach

Large aeronautical structural parts present important distortions after machining. This problem is caused by the presence of residual stresses, which are developed during previous manufacturing steps (quenching). Before being put into service, the nominal geometry is restored by means of mechanical methods. This operation is called reshaping and exclusively depends on the skills of a well-trained and experienced operator. Moreover, this procedure is time consuming and nowadays, it is only based on a trial and error approach. Therefore, there is a need at industrial level to solve this problem with the support of numerical simulation tools. By using a simplification hypothesis, it was found that the springback phenomenon behaves linearly and it allows developing a strategy to implement reshaping at an industrial level. © 2018 Author(s).Peer ReviewedPostprint (author's final draft

Reshaping diagrams for bending straightening of forged aeronautical components

The final publication is available at Springer via http://dx.doi.org/10.1007/s00170-020-05856-zLarge and thick-walled aluminium forgings exhibit shape distortions induced by residual stresses. To restore the nominal geometry, a series of highly manual and time-consuming reshaping operations need to be carried out. In this paper, we are concerned with the development of efficient computer simulation tools to assist operators in bending straightening, which is one of the most common reshaping operations. Our approach is based on the computation of reshaping diagrams, a tool that allows selecting a nearly optimal bending load to be applied in order to minimize distortion. Most importantly, we show that the reshaping diagram needs not to account for the residual stress field, as its only effect is to shift of the reshaping diagram by some offset. That is, the overall behaviour including a realistic 3D residual stress field in a forged part can be retrieved by shifting the residual stress free reshaping diagram by the appropriate offset. Finally, we propose a strategy in order to identify the offset on-the-fly during the reshaping operation using simple force-displacement measures.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 675919.Peer ReviewedPostprint (updated version

Reshaping of large aeronautical structural parts: a simplified simulation approach

Large aeronautical structural parts present important distortions after machining. This problem is caused by the presence of residual stresses, which are developed during previous manufacturing steps (quenching). Before being put into service, the nominal geometry is restored by means of mechanical methods. This operation is called reshaping and exclusively depends on the skills of a well-trained and experienced operator. Moreover, this procedure is time consuming and nowadays, it is only based on a trial and error approach. Therefore, there is a need at industrial level to solve this problem with the support of numerical simulation tools. By using a simplification hypothesis, it was found that the springback phenomenon behaves linearly and it allows developing a strategy to implement reshaping at an industrial level. © 2018 Author(s).Peer Reviewe

Update on the FCC-ee positron source design studies

International audienceThe studies and R&D on the high-intensity positron source for the FCC-ee have been initiated for a while. The positrons are produced by a 6 GeV electron drive-beam incident on a target-converter at 200 Hz. The drive beam comes in 2 bunches spaced by 25 ns with a maximum charge of ~5 nC per bunch. Two scenarios using conventional and hybrid targets are being studied for positron production. According to the FCC CDR, the Flux Concentrator is used as the matching device for the capture system, followed by several accelerating structures embedded in the solenoidal field. Then, the positrons are further accelerated to be injected into the damping ring. Recently, the feasibility study on using a SC solenoid for the positron capture has been started, and the design based on the HTS technology is under investigation. In addition, the large aperture 2 GHz RF structures, which have been specially designed for the FCC-ee positron capture system, are used with the goal of demonstrating accepted positron yield values well beyond the values obtained with state-of-the-art positron sources. The purpose of this paper is to review the current status of the FCC-ee positron source design, highlighting the recent research into the positron production, capture system, primary acceleration, and injection into the damping ring

Study of alternative locations for the SPS Beam Dump Facility

As part of the main focus of the BDF Working Group in 2021, this document reports on the study of alternative locations and possible optimisation that may accompany the reuse of existing facilities with the aim of significantly reducing the costs of the facility. Building on the BDF/SHiP Comprehensive Design Study (CDS), the assessment rests on the generic requirements and constraints that allow preserving the physics reach of the facility by making use of the 4 ⇥1019 protons per year at 400 GeV that are currently not exploited at the SPS and for which no existing facility is compatible. The options considered involve the underground areas TCC4, TNC, and ECN3. Recent improvements of the BDF design at the current location (referred to as ‘TT90-TCC9-ECN4’) are also mentioned together with ideas for yet further improvements. The assessments of the alternative locations compiled the large amount of information that is already available together with a set of conceptual studies that were performed during 2021. The document concludes with a qualitative comparison of the options, summarising the associated benefits and challenges of each option, such that a recommendation can be made about which location is to be pursued. The most critical location-specific studies required to specify the implementation and cost for each option are identified so that the detailed investigation of the retained option can be completed before the end of 2022

Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure.

A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) α-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of "extra-target" RAS suggests the need for RAS screening in all three DAA target regions