Mechanical joining methods for additive manufactured assembly tools

The use of additive manufacturing (AM) processes is growing in the manufacturing industry. One application with great potential for using these processes is the manufacture of assembly tools for a high-ly competitive markets, such as the automotive industry. A critical aspect of the assembly tool design is its capability to incorporate modifications even at a late stage of its development in very short time. In many cases, these modifications are achieved using metal inserts in the polymeric tool, which allow to add new geometric features. This capability increases the usefulness and versatility of components produced by AM and compensate for potential shortcomings of using additive mate-rials. The purpose of this paper is to evaluate the potential use of accessories in additive manufactured com-ponents. In addition, the effect of different percentages of infill tool material on the joining quality of accesso-ries is evaluated. This is done by performing a screw pull-out test on a ABS ESD-7 part, produced by fused deposition modelling. The following different joining solutions were compared and studied in this work: em-bedded inserts, glue, heating processes, pressure (Tap-in) and creation of threads, such as, printing the thread directly and machining the thread onto the material.Programa Operacional Competitividade e Internacionalização - COMPETE 2020, Projeto nº 002814, Ref. POCI-01-0247-FEDER-002814 entre a Univ. do Minho e a Bosc

Presentation and validation of a new optical sensing concept based in a 3d-printing solution

In high competitive markets, such as the automotive industry, the better quality of products, reduction of manufacturing costs and the fulfilment of all delivery deadlines can only be achieved through continuous improvement of production capabilities. One current strategy is to develop and create smarter and adaptive assembly tools. Automation is a relevant area of development in the current industrial world and the baseline of the fourth industrial revolution (Industry 4.0). Namely, it is very important to use sensing components on jigs for assembly parts in the production line. The arrangement of sensing components on the assembly tools is very dependent of the product, making the project more complex and less flexible. This issue can penalise the productivity heavily, especially if a wide range of products and changeover operations are usual. The use of Additive Manufacturing (AM) is growing in the industry and offers a high potential for research and development in the present stage. The AM is advantageous in many areas, especially in the rapid construction of complex tools (RP). This paper presents a new optical sensing concept based on the 3D printing of internal circuits in the assembly tools. This solution can bring many advantages and increase tools flexibility.Programa Operacional de Competividade e Internacionalização - COMPETE 2020, Projeto nº 002814; Ref. POCI-01-0247-FEDER-002814, entre a Univ. Minho e a Bosc

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Caracterização experimental e modelação numérica do comportamento mecânico de chapas multi-camada e multi-material: aplicação à indústria automóvel

Tese de Doutoramento em Engenharia MecânicaNa indústria automóvel, a redução de massa e um design leve e compacto são uma tendência contínua que não mostra sinais de declínio. A pressão para projetar veículos capazes de enfrentar desafios cada vez mais exigentes, como maior economia de combustível, maior segurança e controle eficaz de emissões é constante. Novos materiais avançados reduzem o peso total do veículo, aumentando a eficiência e, assim, reduzindo o consumo geral de combustível. Assim, os fabricantes de automóveis - OEM (Original Equipment Manufacturer) - são obrigados a empregar materiais avançados para garantir que os veículos atendam a normas de emissões cada vez mais rigorosas. Materiais monolíticos metálicos, cerâmicos ou poliméricos não podem satisfazer todas as necessidades tecnológicas para uma variedade de aplicações. Investigadores nas áreas da química e física, bem como engenheiros, entendem que, para obter materiais com propriedades superiores, precisam combinar materiais monolíticos produzindo materiais híbridos. Assim, um tipo de material híbrido especialmente desenvolvido para aplicações industriais, denominado micro-sandwich, tem sido amplamente estudado nas duas últimas décadas. Tratam-se de materiais laminados com duas ou mais camadas de, no mínimo, dois materiais diferentes - chamadas lâminas (lâmina: camada única ou camada) - ligados. A partir destas combinações em estrutura sandwich, é possível “projetar” as propriedades de certo componente ao escolher os materiais monolíticos certos, proporcionando assim a funcionalidade exigida pelos elevados requisitos impostos aos materiais e estruturas modernas. Embora a implementação de materiais sandwich possa contribuir para um bom compromisso entre a redução de peso e o custo do veículo, existem uma série de desafios que precisam ser ultrapassados. Um aspeto fundamental é que, na maior parte das vezes, estes materiais são idealizados e concebidos apenas do ponto de vista de produto final ou aplicação industrial. Porém, as maiores dificuldades relacionam-se com os processos de produção e transformação destes materiais. Por exemplo, os processos de conformação de chapa amplamente utilizados na indústria automóvel requerem um conhecimento profundo da conformabilidade dos materiais. No caso das chapas micro-sandwich, o domínio da conformabilidade é fortemente condicionado pela natureza multi-camada e multi-material do material. Uma tarefa desafiadora relacionada com a caracterização experimental da maioria dos materiais micro-sandwich é a determinação das propriedades desconhecidas do núcleo compósito. As chapas micro-sandwich não são fornecidas com as respetivas propriedades mecânicas e/ou químicas, pelo menos, para todas as camadas. Portanto, falta uma metodologia, simples e robusta, capaz auxiliar a determinação e fornecimento de propriedades mecânicas de chapas micro-sandwich para a indústria. Além disso, não existe nenhum estudo sobre as diferentes abordagens numéricas disponíveis nas ferramentas FEA comerciais de estampagem para modelação e simulação de materiais micro-sandwich. No que diz respeito à análise de cascas 3D para processos de deformação de chapas metálicas, diferentes abordagens FEM podem ser utilizadas, como, por exemplo, elementos casca 2D, elementos casca 3D, elementos sólidocasca e elementos sólidos 3D. Todas estas formulações FE apresentam características próprias que afetam os resultados numéricos em termos de eficiência, precisão e confiabilidade. Não existe um consenso claro na indústria sobre a melhor estratégia FEM para a simulação de processos de conformação de materiais compósitos multi-camada. Para poderem ser usados em produtos industriais, as características relacionadas com a sua estampabilidade devem ser determinadas. Por isso, processos de conformação optimizados, novos materiais e modelos de simulação de processamento de chapas metálicas melhorados estão a tornar-se cada vez mais importantes e necessários para o desenvolvimento bem-sucedido de novos produtos conformados. A presente tese de doutoramento focaliza a caracterização experimental e modelação numérica do comportamento mecânico de chapas multi-camada e multi-material visando a sua implementação em processos de estampagem na indústria automóvel. Todo o trabalho realizado foi desenvolvido em estreita parceria com um dos maiores fornecedores portugueses de produtos estampados para a indústria automóvel, o Grupo SODECIA. As empresas Lamera AB e Thyssenkrupp AG também contribuíram com seus produtos, Hybrix e Litecore S, para os testes experimentais. Além disso, dois dos códigos FE de estampagem comerciais mais comumente usados na indústria automóvel, AutoForm e PAMSTAMP 2G, são profundamente avaliados e comparados antes de serem usados nas simulações de conformação de chapas micro-sandwich. Ao longo desta tese, vários desafios relacionados com a produção e fabricação são discutidos, e diferentes áreas, onde os requisitos de ferramentas de engenharia de projeto precisam ser avaliados em relação aos materiais micro-sandwich e decisões de design, são destacadas para que os fabricantes garantam a competitividade futura do mercado automóvel.In the automotive industry, mass reduction and lightweight design is a continuing trend that does not show signs of declining. The automotive industry is under constant pressure to design vehicles capable of meeting increasingly demanding challenges such as improved fuel economy, enhanced safety and effective emission control. Advanced automotive materials reduce the overall weight of the vehicle, increasing the efficiency and thereby reducing the overall fuel consumption. Automotive OEM (Original Equipment Manufacturer) are compelled to employ advanced automotive materials to ensure that the vehicles meet the increasingly stringent emission norms. Metals, ceramics, or polymers as mono materials cannot fulfill all technological needs for a variety of original applications. Researchers in chemistry and materials, as well as engineers, understand that to obtain materials with superior properties, they have to combine mono materials to hybrids. For industrial applications, the development of a special hybrid material, the micro-sandwich, has been one of the most studied in the last two decades. There are laminates with two or more layers of minimum two different materials—called laminae (lamina: single ply or layer)—bonded together. With these combinations in a sandwich material, it is possible to “design” the properties of particular components with the right choice of mono materials, thus providing the functionality to fulfill the high demands on modern materials and structures. But while implement sandwich materials may contribute to a good compromise between weight reduction and vehicle cost, it also proposes a number of challenges that need to be addressed. A fundamental aspect is that, for the most part, these materials are designed and conceived only from the point of view of final product or industrial application. However, the greatest difficulties are related to the production and transformation processes. For instance, the sheet forming processes widely used in the automotive industry require a deep knowledge of the material’s formability. In the case of the micro-sandwich sheets, the understanding and mastery of the formability is strongly affected by its multi-layer and multi-material nature. A challenging task related with the experimental characterization for most micro-sandwich materials is the determination of the unknow properties of the composite core. The micro-sandwich sheets are not provided with this mechanical and chemical data, at least, for all layers. Therefore, it is missing a simple and robust methodology to supply the mechanical properties of the total micro-sandwich sheet to the industry. Furthermore, there is no study about the different numerical approaches available in the commercial stamping FEA tools to modelling and simulate micro-sandwich materials. Concerning the 3D shell analysis of sheet metal forming processes, different FEM approaches can be used, such as, 2D shell elements, 3D shell elements, solid-shell elements and 3D solid elements. All these FE formulations have particular characteristics which affects the numerical results in terms of efficiency, accuracy and reliability. Therefore, there is not yet a clear consensus in the industry about the most suitable FEM strategy to the sheet metal forming simulation of layered materials. In order to use these layered materials, deep drawing characteristics must be determined before applying them to industrial products. Thus, optimized forming processes, new materials and improved simulation models in sheet metal processing are becoming increasingly important for the successful development of sheet metal parts. The current Phd thesis focuses the experimental characterization and numerical modelling of the mechanical behavior of multi-layer and multi-material sheets, aiming its implementation in industrial automotive stamping processes. All the work carried out was developed in close collaboration with one of the largest portuguese suppliers of automotive stamped products, the SODECIA Group. The companies Lamera AB and Thyssenkrupp AG also contributed with their products, the micro-sandwich materials Hybrix and Litecore S, for the experimental tests. In addition, two of the most popular stamping commercial FE codes in the automotive industry, AutoForm and PAM-STAMP 2G, are deeply evaluated and compared before being used to perform micro-sandwich sheet forming simulations. Throughout this thesis, a number of production and manufacturing related challenges are discussed, and different areas where the requirements of design engineering tools needs to be evaluated concerning the micro-sandwich materials and design decisions are highlighted in order for automotive manufacturers to ensure future market competitiveness.À Fundação para a Ciência e Tecnologia (FCT) pela atribuição da bolsa com referência SFRH/BDE/51189/201

Assembly workstation and installation method thereof

Assembly workstation for assembling products by a person, comprising a lower workbench base nest and an upper workbench mask nest, wherein the base nest and mask nest define an assembly jig for said products; a support frame; a vertically displaceable platform for receiving said base nest; and an actuator attached to the support frame and attached to the platform for creating vertical displacement of said platform; wherein said lower workbench base nest is arranged onto said platform and said upper workbench mask nest is pivotably coupled to said support frame for rotating about a transversal horizontal axis. The assembly workstation of the present disclosure is a universal, ergonomic assembly workstation using modular additivemanufacturing tools.FEDER-Programa COMPETE 2020, Project nº 002814, Ref: POCI-01-0247-FEDER-002814

W and Z boson production in p-Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV

The W and Z boson production was measured via the muonic decay channel in proton-lead collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV at the Large Hadron Collider with the ALICE detector. The measurement covers backward (−4.46 10 GeV/c are determined. The results are compared to theoretical calculations both with and without including the nuclear modification of the parton distribution functions. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions within uncertainties

J/ψ\psi production as a function of charged-particle pseudorapidity density in p-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

We report measurements of the inclusive J/ ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at sNN=5.02TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ ψ yield with normalised dNch/dη , measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity

The ALICE Transition Radiation Detector: construction, operation, and performance

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ c in p–Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection