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  • 1.
    Ahlqvist, Karin
    RISE, Swerea, SWECAST.
    Bindemedel med låg miljöpåverkan - Kvantifiering av kondensat2012Report (Other academic)
    Abstract [sv]

    Bildandet av kondensat i samband med gjutning kan ställa till problem vid utformning av ventilation samt vid värmeåtervinning kopplat till ventilationen. I detta projekt har mängden kondensat som bildas vid gjutning på olika typer av bindemedel kvantifierats. Cold Box (generation III), Hot Box, Resol och två varianter av nyutvecklade oorganiska bindemedel har analyserats inom ramen för detta projekt. En utmaning i arbetet har varit att finna en metod att i laboratorieskala, med små provkroppar, kunna samla upp och med acceptabel mätnoggranhet säkerställa resultaten. För detta ändamål har en sk. Cogas AL-utrustning använts. Resultatet visar att organiska bindemedel generar en större mängd kondensat jämfört med oorganiska bindemedlen. Vidare framkommer att Cold Box generear en något lägre kondensatmängd än vad som kan förväntas. Detta kan förklaras med en lägre bindemedelstillsats. Slutligen visar resultatet att även de oorganiska bindemedlen generar en inte obetydlig mängd kondensat. Det senare var överraskande och är betydelsefullt vid framtida dimensionering av ventilationssystemen. Med de nya rönen att även de oorganiska bindemedlen genererar relativt stora kondensatmängder har frågan aktualiserats vad detta kondensat består av och om det innehållsmässigt skiljer sig från kondensat från de organiska bindemedlen. Den använda Cogas-metoden ger möjlighet att genomföra denna typ av analyser men det har inte rymts inom detta projekt.

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  • 2.
    Ahlström, Johan
    et al.
    RISE, Swerea, KIMAB.
    Tidblad, Johan
    RISE, Swerea, KIMAB. RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Sederholm, Bror
    RISE, Swerea, KIMAB.
    Wadsö, L.
    Lund University, Sweden.
    Influence of chloride and moisture content on steel rebar corrosion in concrete2016In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 67, no 10, p. 1049-1058Article in journal (Refereed)
    Abstract [en]

    Reinforced mortar samples were exposed in humidity chambers with different relative humidity or exposed in cyclic moisture conditions. The rebars were in an “as received” condition meaning that the preexisting oxide scale were intact. The lowest chloride concentration that initiated corrosion was 1% Cl− by mass of cement, corrosion was then observed for samples exposed at 97% relative humidity. It is suggested that the corrosion rate decreases when samples are exposed to a relative humidity lower than 97%. The results indicate that threshold levels should be evaluated at rather humid conditions (97%) despite the fact that the maximum corrosion rate at higher chloride levels is observed in the interval 91–94%. For samples exposed to cyclic moisture conditions, a lower chloride concentration was needed to initiate corrosion compared to samples exposed in static moisture conditions.

  • 3.
    Aitomäki, Yvonne
    et al.
    RISE, Swerea, SICOMP.
    Hagström, Bengt
    RISE, Swerea, IVF.
    Långström, Runar
    RISE, Swerea, SICOMP.
    Fernberg, Patrik
    RISE, Swerea, SICOMP.
    Novel reactive bicomponent fibres: Material in composite manufacturing2012In: Journal of Nanostructured Polymers and Nanocomposites, ISSN 1790-4439, Vol. 8, no 1, p. 5-11Article in journal (Refereed)
    Abstract [en]

    The hypotheses that reactive uncured, thermoset bicomponent fibres can be prepared and mixed with reinforcing fibres and ultimately used in preparation of a composite was tested and is described. It is thought that such fibres have the two potential advantages: (1) to enable manufacturing with particle doped resins e.g. nanocomposites which add functionality to composites and (2) increased efficiency of structural composite manufacturing by increasing the level of automation. The structure of the thermoset fibres comprises of a sheath of thermoplastic and a core of uncured thermoset resin. Once manufactured, the fibres were wound with a reinforced fibre onto a plate, consolidated and cured. The resulting composite was examined and compared to other composites made with the same manufacturing method from commercially available materials. The results show that a laminate can be produced using these reactive bicomponent fibres. The resin system successfully impregnates the reinforcing carbon fibres and that the thermoplastic separates from the epoxy resin system during consolidation. In comparison to reference material, the bicomponent laminate shows promising characteristics. However, the processes developed are currently on a lab-scale and considerable improvement of various bicomponent fibre properties, such as the strength, are required before the technology can be used on a larger scale.

  • 4.
    Alipour, Yousef
    et al.
    KTH Royal Institute of Technology, Sweden.
    Viklund, Peter
    RISE, Swerea, KIMAB.
    Henderson, Pamela J.
    Vattenfall, Sweden.
    The analysis of furnace wall deposits in a low-NOx waste wood-fired bubbling fluidised bed boiler2012In: VGB PowerTech, ISSN 1435-3199, Vol. 92, no 12, p. 96-100Article in journal (Refereed)
    Abstract [en]

    Increasing use is being made of biomass as fuel for electricity production as the price of natural wood continues to rise. Therefore, more use is being made of waste wood (recycled wood). However, waste wood contains more chlorine, zinc and lead, which are believed to increase corrosion rates. Corrosion problems have occurred on the furnace walls of a fluidised bed boiler firing 100 % waste wood under low-NOx conditions. The deposits have been collected and analysed in order to understand the impact of the fuel.

  • 5.
    Andersons, J.
    et al.
    University of Latvia, Latvia.
    Modniks, J.
    University of Latvia, Latvia; Ventspils University College, Latvia.
    Joffe, Roberts
    RISE, Swerea, SICOMP. Luleå University of Technology, Sweden.
    Madsen, B.
    DTU Technical University of Denmark, Denmark.
    Nättinen, K.
    Bemis Flexible Packaging Europe, Finland.
    Apparent interfacial shear strength of short-flax-fiber/starch acetate composites2016In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 64, p. 78-85Article in journal (Refereed)
    Abstract [en]

    The paper deals with an indirect industry-friendly method for identification of the interfacial shear strength (IFSS) in a fully bio-based composite. The IFSS of flax fiber/starch acetate is evaluated by a modified Bowyer and Bader method based on an analysis of the stress-strain curve of a short-fiber-reinforced composite in tension. A shear lag model is developed for the tensile stress-strain response of short-fiber-reinforced composites allowing for an elastic-perfectly plastic stress transfer. Composites with different fiber volume fractions and a variable content of plasticizer have been analyzed. The apparent IFSS of flax/starch acetate is within the range of 5.5-20.5 MPa, depending on composition of the material. The IFSS is found to be greater for composites with a higher fiber loading and to decrease with increasing content of plasticizer. The IFSS is equal or greater than the yield strength of the neat polymer, suggesting good adhesion, as expected for the chemically compatible constituents.

  • 6.
    Andersson, J.
    et al.
    RISE, Swerea, KIMAB.
    Persson, Daniel
    RISE, Swerea, KIMAB.
    Jönsson, D.
    Scania CV, Sweden.
    Tornberg, Malin
    RISE, Swerea, KIMAB.
    Lindh-Ulmgren, Eva
    RISE, Swerea, KIMAB.
    Degradation of carbon fiber reinforced composites induced by galvanic coupling to metallic materials2015In: European Corrosion Congress, EUROCORR 2015, Austrian Society for Metallurgy and Materials (ASMET) , 2015Conference paper (Refereed)
  • 7.
    Andersson, O.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Semere, D.
    KTH Royal Institute of Technology, Sweden.
    Melander, Arne
    RISE, Swerea, KIMAB. KTH Royal Institute of Technology, Sweden.
    Arvidsson, M.
    Volvo Car Corporation, Sweden.
    Lindberg, B.
    KTH Royal Institute of Technology, Sweden.
    Digitalization of Process Planning of Spot Welding in Body-in-white2016In: Procedia CIRP, Elsevier B.V. , 2016, p. 618-623Conference paper (Refereed)
    Abstract [en]

    Process planning of spot welding for body-in-white automobile structures involves several experimental (physical) welding trials to set the process parameters. These experimental trials are crucial in ensuring the quality and efficiency of the process. However, due to the iterative nature of the work, running several experiments is costly and time consuming prolonging the overall development cost and time significantly. To minimize the cost and time, replacing the physical tests by digital (virtual) tests is an established approach although not often applied for spot welding. However, for a long chain of development process with several iterative loops, this is not a trivial task considering the availability of information and continuity of the work flow. This paper reports the work and results of an industrial case study conducted on spot welding of a body-in-white car pillar in a Swedish auto manufacturer. The aim of the study is to investigate and propose the necessary conditions required to replace a physical test by virtual tests in terms of validity and expedited execution of the process. Information sharing, knowledge reuse and streamlining the work flow have found to be critical condition for valid and rapid virtual tests. © 2016 The Authors.

  • 8.
    Andre, Alann
    et al.
    RISE, Swerea, SICOMP.
    Norrby, Monica
    KTH Royal Institute of Technology, Stockholm.
    Åkermo, Malin
    KTH Royal Institute of Technology, Sweden.
    Nilsson, Sören
    RISE, Swerea, SICOMP.
    Nyman, Tonny
    KTH Royal Institute of Technology, Sweden; Saab, Sweden.
    An experimental and numerical study of the effect of some manufacturing defects2013In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2013, p. 4105-4112Conference paper (Refereed)
    Abstract [en]

    During the manufacturing process of composite structural parts, layer of fabrics or unidirectional prepreg may have to be cut in order to fulfil production requirements. From a general mechanical point of view, cutting fibres in a composite part has a large negative impact on the mechanical properties. However, such interventions are necessary in particular cases, for example due to draping of complex geometries. A rather extensive test program was launched to investigate the effects of defects that typically could arise during manufacturing. The overall purpose of the test program was to determine knock-down factors on strength for typical manufacturing defects that occasionally arise and sometimes are hard to avoid in production: cuts/gaps and fibre angle deviations. Four types of specimens were tested, reference, intersection of cuts in adjacent layers combined with a bolt hole, cut in a zero degree ply combined with a bolt hole and specimens with misaligned fibres. The specimens with misaligned fibres were tested with three different fibre angles. In addition to the experimental procedure, FE-analyses utilising cohesive elements were conducted, and after mechanical tests, Non Destructive Investigation (NDI) and fractographic investigations were performed. An excellent correlation between analyses and experiments were obtained.

  • 9.
    Ankerfors, Caroline
    et al.
    RISE, Swerea, KIMAB.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Polyelectrolyte complexes for tailoring of wood fibre surfaces2014In: Advances in Polymer Science, ISSN 0065-3195, E-ISSN 1436-5030, Vol. 256, p. 1-24Article in journal (Refereed)
    Abstract [en]

    The use of polyelectrolyte complexes (PECs) provides new opportunities for surface engineering of solid particles in aqueous environments to functionalize the solids either for use in interactive products or to tailor their adhesive interactions in the dry and/or wet state. This chapter describes the use of PECs in paper-making applications where the PECs are used for tailoring the surfaces of wood-based fibres. Initially a detailed description of the adsorption process is given, in more general terms, and in this respect both in situ formed and pre-formed complexes are considered. When using in situ formed complexes, which were intentionally formed by the addition of oppositely charged polymers, it was established that the order of addition of the two polyelectrolytes was important, and by adding the polycation first a more extensive fibre flocculation was found. PECs can also form in situ by the interaction between polyelectrolytes added and polyelectrolytes already present in the fibre suspension originating from the wood material, e.g. lignosulphonates or hemicelluloses. In this respect the complexation can be detrimental for process efficiency and/or product quality depending on the charge balance between the components, and when using the PECs for fibre engineering it is not recommended to rely on in situ PEC formation. Instead the PECs should be pre-formed before addition to the fibres. The use of pre-formed PECs in the paper-making process is described as three sub-processes: PEC formation, adsorption onto surfaces, and the effect on the adhesion between surfaces. The addition of PECs, and adsorption to the fibres, prior to formation of the paper network structure has shown to result in a significant increase in joint strength between the fibres and to an increased strength of the paper made from the fibres. The increased joint strength between the fibres is due to both an increased molecular contact area between the fibres and an increased molecular adhesion. The increased paper strength is also a result of an increased number of fibre/fibre contacts/unit volume of the paper network. 

  • 10.
    Ansari, Farhan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Galland, Sylvain
    KTH Royal Institute of Technology, Sweden.
    Fernberg, Patrik
    RISE, Swerea, SICOMP.
    Berglund, Lars A.
    KTH Royal Institute of Technology, Sweden.
    Stiff and ductile nanocomposites of epoxy reinforced with cellulose nanofibrils2013In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2013, p. 5575-5582Conference paper (Refereed)
  • 11.
    Apruzzese, Paola
    et al.
    Imperial College London, UK.
    Olsson, Robin
    RISE, Swerea, SICOMP.
    Falzon, Brian
    Monash University, Australia.
    Modelling the postbuckling behaviour of impacted composite structures2009In: Proc. 17th Int. Conf. on Composite Materials (ICCM-17), 2009, article id F7:11Conference paper (Refereed)
    Abstract [en]

    Two approaches to modelling the effects of embedded defects and impact damage in composite aerostructures are presented. These differ in the manner in which the damage is represented; one as an equivalent delamination and the other as a soft inclusion with non-linear homogenized material properties. These techniques are applied to study the effects of defects and impact damage on the performance of composite panels.

  • 12.
    Asp, Lars Erik
    et al.
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Greenhalgh, Emile S.
    Imperial College London, United Kingdom.
    Structural power composites2014In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 101, p. 41-61Article in journal (Refereed)
    Abstract [en]

    This paper introduces the concept of structural power composite materials and their possible devices and the rationale for developing them. The paper presents a comprehensive review of the state-of-the-art, highlighting achievements related to structural battery and supercapacitor devices. The research areas addressed in detail for the two types of material devices include: carbon fibre electrodes, structural separators, multifunctional matrix materials, device architectures and material functionalization. Material characterisation, fabrication and validation are also discussed. The paper culminates in a detailed description of scientific challenges, both generic as well as device specific, that call for further research. Particular reference is given to work performed in national and European research projects under the leadership of the authors, who are able to provide a unique insight into this newly emerging and exciting field.

  • 13.
    Asp, Leif
    et al.
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Leijonmarck, Simon
    RISE, Swerea, SICOMP. KTH Royal Institute of Technology, Sweden.
    Carlson, Tony
    RISE, Swerea, SICOMP.
    Lindbergh, G.
    KTH Royal Institute of Technology, Sweden.
    Realisation of structural battery composite materials2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    This paper introduces the concept of structural battery composite materials and their possible devices and the rationale for developing them. The paper presents an overview of the research performed in Sweden on a novel structural battery composite material. The research areas addressed include: carbon fibre electrodes, structural separators, multifunctional matrix materials, device architectures and material functionalization. Material characterization, fabrication and validation are also discussed. The paper focuses on a patented battery composite material technology. Here, carbon fibres are employed as combined negative battery electrodes and reinforcement, coated with a solid polymer electrolyte working simultaneously as electrolyte and separator with ability to transfer mechanical loads. The coated fibres are distributed in a conductive positive cathode material on an aluminium electron collector film. Efficient Li-ion transport between the electrodes is achieved by the solid polymer electrolyte coating being only a few hundred nanometres thick. Finally some outstanding scientific and engineering challenges are discussed. Such challenges, calling for further research are related to manufacture, development of new solid polymer electrolytes for improved multifunctionality and the lack of material models. 

  • 14.
    Bachinger, Angelika
    et al.
    RISE, Swerea, SICOMP.
    Marklund, Erik
    RISE, Swerea, SICOMP. Luleå University of Technology, Sweden.
    André, Alann
    RISE, Swerea, SICOMP.
    Hellström, Peter
    RISE, Swerea, SICOMP.
    Rössler, Joraine
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Asp, Leif
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Materials with variable stiffness2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    In this study different concepts to attain a material that can reduce its stiffness upon external stimulation were evaluated regarding their suitability for traffic safety applications. All concepts rely on resistive heating of a carbon fibre reinforcement upon application of electric current through the fibres. The stiffness reduction is achieved by a phase transformation due to heating of the material. The phase transformation takes place either in a thermoplastic interphase, in a thermoplastic matrix or in a thermoset matrix, depending on the concept. The different concepts were studied regarding their thermomechanical and processing properties and their ability to reduce their stiffness upon application of an electric current was tested. Moreover, the materials were evaluated regarding their potential for fast activation, which is crucial for applications in traffic safety. Stiffness-reduction was achieved upon application of an electric current, where the activation temperature was between 60 and 120°C and the extent of stiffness-reduction varied between 50 and 90%, depending on the material. The response time was found to depend to a large extent on the amount of material, which leads to the conclusion that smart design solutions are required for larger parts. It is concluded that the concepts vary in their thermal, mechanical and processing properties as well as in their extent of stiffness-reduction upon activation. The results presented in this work prove the feasibility of the studied materials for traffic safety applications and the concepts allow further optimization of the materials for specific applications

  • 15.
    Bachinger, Angelika
    et al.
    RISE, Swerea, SICOMP.
    Rössler, Joraine
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Asp, Lars Erik
    RISE, Swerea, SICOMP. Chalmers University of Technology, Sweden.
    Electrocoating of carbon fibres at ambient conditions2016In: Composites Part B: Engineering, ISSN 1359-8368, E-ISSN 1879-1069, Vol. 91, p. 94-102Article in journal (Refereed)
    Abstract [en]

    Electrocoating at constant current is less sensitive to moisture and oxygen than electrocoating at controlled potential, which makes it more interesting for industrial implementation. The galvanostatic electrocoating of carbon fibres with Poly(methylmethacrylate) (PMMA) was therefore studied and compared to the well researched potentiostatic electrocoating procedure. The influence of different experimental parameters on the coating efficiency was investigated in order to identify the mechanisms that are involved in the cathodic electrocoating at constant current. It could be confirmed that the involved mechanisms differ from potentiostatic electrocoating and it was found that galvanostatic electrocoating is more efficient at ambient conditions compared to potentiostatic electrocoating. Polymer layers that cover the entire carbon fibre surface could be achieved in a continuous process by galvanostatic electrocoating under ambient conditions. 

  • 16.
    Bardh, Jonas
    RISE, Swerea, SWECAST.
    Trycktäthet i gjutgods2012Report (Other academic)
    Abstract [sv]

    Denna rapport är en sammanställning av det arbete som gjorts i projekt G833M, ”Trycktäthet i gjutgods”. Idag finns problem med läckande gjutgods och ibland får det stora konsekvenser. Ur miljösynpunkt så får t ex inte olja läcka ut från en motor på en bil. Så ämnet är högaktuellt i dagens samhälle där miljöfrågor får ett allt större fokus. Uppgiften med arbetet var att tydliggöra vad som menas med trycktätt gods, (hur man definierar begreppet trycktäthet). Hur ett tätkrav bör vara utformat och vilka provningsmetoder som finns, och vilka begränsningar de har, har också gåtts igenom. Syftet med artetet har varit att ge en ökad förståelsen för trycktäthet och de provningsmetoder som finns. En korrekt utformad kravsättning bidrar också till att säkerställa att rätt provningsmetod används. Allt för ofta är det kommunikationen mellan köpare och tillverkare som är bristfällig vilket leder till läckageproblem. Genom en ökad kunskap och förståelse hos båda parter bidrar till rätt ställda förväntningar på det färdiga godset. Arbetet har till största del bedrivits genom litteraturstudier och genom några studiebesök hos ett antal företag i branschen.

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  • 17.
    Bein, T.
    et al.
    Fraunhofer LBF, Germany.
    Mayer, D.
    Fraunhofer LBF, Germany.
    Hagebeuker, L.
    Institut für Kraftfahrzeuge, Germany.
    Bachinger, Angelika
    RISE, Swerea, SICOMP.
    Bassan, D.
    C.R.F. S.C.p.A, Italy.
    Pluymers, B.
    KU Leuven, Belgium.
    Delogu, M.
    Università degli Studi di Firenze, IItaly.
    Enhanced Lightweight Design - First Results of the FP7 Project ENLIGHT2016In: Transportation Research Procedia, E-ISSN 2352-1465, p. 1031-1040Article in journal (Refereed)
    Abstract [en]

    The European Green Vehicle project ENLIGHT aims to advance highly innovative lightweight material technologies for application in structural vehicle parts of future volume produced Electric Vehicles (EVs) along four axes: performance, manufacturability, cost effectiveness and lifecycle footprint. The main target is to develop viable and sustainable solutions for medium production volume up to 50.000 EVs destined to reach the market in the next 8-12 years. The specific objectives of the ENLIGHT project are on holistic and integrated conceptual design and manufacturing concerning how the technologies and materials addressed can be combined into a representative medium-volume EV. The solutions will be demonstrated in five modules: a front module and central floor module, a front door, a sub-frame and suspension system as well as a cross-car beam. In this paper, a summary of the major results obtained up to the 3rd project year will be presented. © 2016 The Authors.

  • 18. Bellgran, M
    et al.
    Gullander, Per
    RISE, Swerea, IVF.
    Harlin, Ulrika
    RISE, Swerea, IVF.
    Towards Improvement of Production Efficiency and Effectivenessfrom a Life-Cycle Perspective2002Conference paper (Refereed)
    Abstract [en]

    Low operation equipment efficiency, OEE, in manufacturing industry indicates a potential for improvements by reducing production disturbances during the life cycle of a production system. Here, the question of preventing and handling production disturbances in the production system during its design, start-up, ramp-up and full production phases is concerned. It requires measurement of performance, and utilisation of process data and information of production disturbances appearing during the different life cycle phases. It also requires a focus on eliminating production disturbances already during the production system design process. The objective of the research project presented in this paper is to develop a methodology for analysing and dealing with production disturbances on both a short-term and long-term basis, including also the utilisation of software support. The ongoing development of the methodology is based on, and will be applied in extensive case studies at Swedish manufacturing companies. Keywords Production efficiency, effectiveness, production disturbances, production system, life-cycle perspective, methodology development.

  • 19.
    Bellqvist, David
    et al.
    RISE, Swerea, MEFOS.
    Wang, Chuan
    RISE, Swerea, MEFOS.
    Nilsson, Leif
    SSAB EMEA, Sweden.
    Techno-economic analysis of low temperature waste heat recovery and utilization at an integrated steel plant in Sweden2014In: Chemical Engineering Transactions, ISSN 1974-9791, E-ISSN 2283-9216, Vol. 39, no Special Issue, p. 67-72Article in journal (Refereed)
    Abstract [en]

    Energy consumption and CO2 emissions is an ever-present issue for energy intensive industries, such as the steel industry. The work for reducing the environmental impact is a strong interest among the governments in Europe and the 20-20-20 targets, decided by the EU, set the targets for the year 2020 to increase energy efficiency by 20 %, reduce greenhouse gas emissions by 20 %, and increase the use of renewable energy to 20 %. It is therefore important for the steel industry, and other industries, to continuously be working on development of concepts for decreasing the environmental impact, which are also financially viable. This paper presents the work that has been conducted in order to evaluate the potential benefits regarding energy- & cost saving and CO2 mitigation, when recovering and utilizing low temperature waste heat at an integrated steel plant in Sweden, SSAB EMEA Lulea. In order to achieve a holistic overview of the plant a process integration approach is applied to evaluate the effects that occur when applying technologies for waste heat recovery. The results indicate a potential for energy saving of 1.9 %, and a corresponding CO2 mitigation potential of 1.5 %. The calculated payback time for the applied waste heat recovery concepts, which is based on specific methods and economic assumptions, range between 1.5 - 7.0 y. 

  • 20.
    Bellqvist, David
    et al.
    RISE, Swerea, MEFOS.
    Wang, Chuan
    RISE, Swerea, MEFOS.
    Nilsson, Leif
    SSAB, Sweden.
    Techno-economic analysis of low temperature waste heat recovery and utilization at an integrated steel plant in Sweden2014In: 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2014, Czech Society of Chemical Engineering , 2014, Vol. 4, p. 2200-Conference paper (Refereed)
  • 21.
    Ben Kahla, H.
    et al.
    Luleå University of Technology, Sweden.
    Varna, J.
    Luleå University of Technology, Sweden.
    Pupurs, Andrejs
    RISE, Swerea, SICOMP. Luleå University of Technology, Sweden.
    Microcracking in layers of composite laminates in cyclic loading with tensile transverse stress component in layers2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    Intralaminar cracking in layers of a quasi-isotropic carbon fiber NCF laminate in tension-tension cyclic loading is studied experimentally. Methodology based on modified Weibull analysis is suggested to combine quasi-static and fatigue testing to identify parameters in the crack density growth model. The validity of the assumptions for the given material is experimentally confirmed. The suggested methodology can lead to significant time and material savings in composites fatigue behaviour characterization. 

  • 22.
    Bengtson, Arne
    et al.
    RISE, Swerea, KIMAB.
    Hildebrand, L.
    Technical University of Dortmund, Germany.
    Expert systems for prediction of corrosion properities of Zn-based coatings from the chemical analysis2012In: Yejin Fenxi/Metallurgical Analysis, ISSN 1000-7571, Vol. 32, no 4, p. 1-5Article in journal (Refereed)
    Abstract [en]

    The purpose of the work is to develop a general method, to predict the corrosion resistance of Zn-based coatings, expressed as total mass loss in an accelerated salt spray test. The method is to be based on just three analytical parameters; the total coating weights of Zn, Al and Mg. The reason for this restriction is that determination of these three parameters is possible in on-line analysis. The predicted corrosion resistance could then be included in a process/quality control system. Accelerated corrosion tests have been carried out by Swerea KIMAB IC (Institut de Corrosion) in Brest, and CRM in Belgium. Test were run according to the Renault ECC1 test D172028/-C (12 weeks), and with an accelerated cyclic corrosion test developed by CRM. The materials were divided into four corrosion classes according to total mass loss. All corrosion experiments show clearly the well documented positive influence of magnesium and aluminium. In relation to the masses of these elements in the coatings, the influence of both elements is considerably higher than the influence of zinc alone. For this reason, a new quantity is introduced, called "equivalent Zn coating weight". This quantity is a linear combination of the coating weights of zinc, aluminium and magnesium. A model for prediction of corrosion resistance was developed with the expert system, based on a combination of regression analysis and a "decision tree" algorithm. The model was able to correctly classify 25 out of 27 materials based on just the three analytical parameters mentioned above: the total coating weights of zinc, aluminium and magnesium. In conclusion, the approach shows that an accurate prediction of the corrosion behaviour is possible even on-line. For purposes of material development, the expert system can also be expanded to include additional analytical parameters.

  • 23.
    Bengtson, Arne
    et al.
    RISE, Swerea, KIMAB.
    Sedlakova, Miroslva
    RISE, Swerea, KIMAB.
    Didriksson, R.
    SSAB, Sweden.
    Rapid inclusion characterisation by pulse distribution analysis optical emission spectroscopy-recent development2013In: Yejin Fenxi/Metallurgical Analysis, ISSN 1000-7571, Vol. 33, no 1, p. 7-12Article in journal (Refereed)
    Abstract [en]

    The purpose of the work is to further develop and validate the optical emission method pulse distribution analysis (PDA) for rapid inclusion characterisation in steel production. The experimental work was focused on investigation of several operational parameters: spark energy, spark frequency and time gating of signal acquisition. The results showed that a low spark energy improves the detection limit, but at the expense of measuring statistics due to a smaller sample volume. The measuring frequency proved to have no significant influence on the analytical results, but several existing instruments cannot handle the highest spark frequencies above about 300 Hz in PDA mode due to limitations in the electronics. Investigation of time gating (TRS) gave only a marginal improvement in the detection limit of Si outliers above the metallic content. The work also revealed that there is a risk to detect "false" outliers due to asymmetric intensity distributions. This has resulted in the development of more advanced algorithms for outlier detection, increasing the accuracy of the method. Another limitation found is that the particle number density must not exceed about 10 000 inclusions/mm3 for the method to effectively detect single inclusions. A method to overcome this limitation has been suggested, but not yet evaluated. The accuracy of quantitative determination of the Al content in inclusions has been verified by reference methods. In conclusion, it has been demonstrated that state-of-the-art PDA is a very powerful technique for rapid inclusion characterisation in steels. Furthermore, the speed of analysis is sufficiently high for process feedback and controllable.

  • 24. Berglund, M
    et al.
    Harlin, Ulrika
    RISE, Swerea, IVF.
    Stahre, J
    VERTICAL INFORMATION TRANSFER IN KNOWLEDGE INTENSE MANUFACTURING2004Conference paper (Refereed)
    Abstract [en]

    The objective of this paper is to highlight vertical information transfer in relation to operator involvement in development work and to analyze the information channels utilized. A special focus is put on product, production, organisation and information system development. Data were collected in 14 Swedish companies through interviews with operators, production support, and production management. The study indicated a need of strategies for vertical information distribution. Verbal information channels are mostly used. However, formalized information transfer is needed to better utilize the operators’ knowledge and experience for development work as well as to provide personnel with relevant knowledge required for their work. Information flow may be simplified through IT-systems, intranet, documents and instructions, but it implies strong support from management and adapted working methods.

  • 25.
    Berglund, Martina
    et al.
    Linköpiing University, Sweden.
    Harlin, Ulrika
    RISE, Swerea, IVF.
    Knowledge transfer during personnel changes in manufacturing2007Conference paper (Refereed)
    Abstract [en]

    This case based research addresses knowledge transfer when employees change positions or roles during planned changes within manufacturing. The studies demonstrate that these changes are common. Knowledge needed to transfer includes technical, human and organizational issues. Furthermore, there is a need to transfer knowledge during formal changes of position as well as temporary changes of roles. Organizational structures for knowledge transfer must therefore be developed for transfer of explicit and implicit knowledge in formal and informal settings. This may be achieved through a combination of codified explicit knowledge, organized networks and by creating opportunities for learning from work in practice.

  • 26.
    Berglund, Martina
    et al.
    Linköping University, Sweden.
    Harlin, Ulrika
    RISE, Swerea, IVF. Chalmers University of Technology, Sweden.
    Gullander, Per
    RISE, Swerea, IVF.
    Challenges in a product introduction in a cross-cultural work system – a case study involving a Swedish and a Chinese company2012Conference paper (Refereed)
    Abstract [en]

    The objective of this case study is to gain deeper insights in how cultural aspects influence a product introduction with product development carried out in Sweden and industrialization in China. Data were collected through semi-structured individual and group interviews and workshops. The study showed that the companies faced a number of challenges during the product introduction, such as problems with the product design, updating versions of drawings, infrastructure for communication, and quality issues. There were, however, a number of issues that were directly or indirectly influenced by cultural aspects and lack of understanding about cultural differences. Challenges included interpersonal communication related to language barriers and differences in degree of direct communication of needs, demands and own capabilities. Based on literature on cultural dimensions and actual challenges during a specific product introduction when two national cultures interact/collaborate, this paper results in an initial approach for further model development and research on how to link cultural dimensions to product development models in a systematic and prioritized way. This is needed to develop organizational support to increase knowledge of cultural strengths and differences, how to manage these issues and further facilitate organizational learning for increased efficiency of product introductions.

  • 27. Berglund, Martina
    et al.
    Harlin, Ulrika
    RISE, Swerea, IVF.
    Säfsten, Kristina
    Knowledge gained from product introduction and implications for organizational learning2008Conference paper (Refereed)
    Abstract [en]

    Empirical findings from the automotive industry demonstrate that knowledge gained during a product introduction is mainly related to work procedures, personnel resources, education and training, verification, and responsibilities. However, this is to a large extent individually based. Examples of means to make this knowledge accessible to others include integrated work procedures and networking when knowledge is developed in a person-to-person situation as well codification of some knowledge. This is achieved through allocation of personnel resources and emphasis on organizational learning on the company agenda as well as in design of work procedures, which are management tasks and responsibilities.

  • 28.
    Bjelkemyr, Marcus
    et al.
    RISE, Swerea, IVF.
    Shahbazi, Sasha
    RISE, Swerea, IVF.
    Jönsson, C.
    Mälardalen University, Sweden.
    Wiktorsson, Magnus
    RISE, Swerea, IVF.
    Individuals’ perception of which materials are most important to recycle2015In: IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS 2015, Springer New York LLC , 2015, p. 723-729Conference paper (Refereed)
    Abstract [en]

    In this study, we have asked respondents to rank ten different waste fractions that are both common in manufacturing industry and easily recognizable. The purpose of the study has been to clarify to what extent individuals are able to identify the waste fractions that are most important to recycle from an environmental perspective. The individuals’ perception has then been correlated with a life cycle assessment of the ten materials. In addition, the respondents were also asked to rank the fractions according to cost. The results show that metals are consistently considered most important to recycle, and plastics are commonly among the top five amongst the ten waste fractions together with glass. The cellulose based fractions, cotton, and compost are commonly rated low. In addition, there is a perceived correlation between the environmental and economic impact.

  • 29.
    Bjornsson, A.
    et al.
    Linköping University, Sweden.
    Lindback, J. -E
    Saab Aerostructures, Sweden.
    Eklund, Daniel
    RISE, Swerea, SICOMP.
    Jonsson, Marie
    RISE, Swerea, SICOMP.
    Low-cost Automation for Prepreg Handling - Two Cases from the Aerospace Industry2015In: SAE International Journal of Materials & Manufacturing, ISSN 1946-3979, E-ISSN 1946-3987, Vol. 9, no 1, p. 68-74Article in journal (Refereed)
    Abstract [en]

    With an increased use of composite materials within the aerospace industry follows a need for rational and cost-effective methods for composite manufacturing. Manual operations are still common for low to medium manufacturing volumes and complex products. Manual operations can for example be found in material handling, when picking prepreg plies from a cutter table and stacking them to form a plane laminate in preparation for a subsequent forming operation. Stacking operations of this kind often involves a great number of different ply geometries and removal of backing paper and other protecting materials like plastic. In this paper two different demonstrator cells for automated picking of prepreg plies and stacking of plane laminates are presented. One demonstrator is utilizing a standard industrial robot and an advanced end-effector to handle the ply variants. The other demonstrator is using a dual arm robot which allow for simpler end-effector design. In combination with a previously developed system for automated removal of backing papers both systems have shown to be capable of automatically picking prepreg plies from a plane surface and stack them to generate a flat multistack laminate. The dual arm approach has shown advantageous since it result in simpler end-effector design and a successive lay down sequence that result in good adhesion between the plies in the laminate. null.

  • 30.
    Bjurenstedtare, Anton
    RISE, Swerea, SWECAST.
    Examination of laser treated aluminium2019Report (Other academic)
    Abstract [en]

    The laser treatments of the surfaces have influenced the surface appearance and the microstructure. The effect on the surface appearance is shown in Figure 6. Examination of cross sections revealed a 3-10 μm thick layer of, what appears to be aluminium (based on ocular examination), has formed. The examination in the SEM-EDS gave no answer on the composition of the surface layer formed.

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  • 31.
    Björnsson, A.
    et al.
    Linköping University, Sweden.
    Jonsson, Marie
    RISE, Swerea, SICOMP.
    Johansen, K.
    Linköping University, Sweden.
    Automation of composite manufacturing using off-the-shelf solutions; three cases from the aerospace industry2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    With an increased use of composite materials follows a need for rational, cost-efficient manufacturing processes. This paper explores how off-the-shelf solutions, developed for other purposes than composite manufacturing, can be used to build systems for automated composite manufacturing. Three demonstrators, each of them dealing with a specific type of material and all of them representing different manufacturing technologies for automated composite manufacturing, are presented and analyzed to find aspects that affect the ability to use off-the-shelf solutions. The three demonstrators target low to medium manufacturing volumes of complex products and they have been developed in collaboration with industrial partners within the aerospace industry. The conclusions drawn from the development of the demonstrators are that it is technically feasible to use off-the-shelf solutions in the three cases while adhering to the high quality standards of the industry. Furthermore three groups of aspects, quality aspects, product aspects and system aspects, which affect the ability to use off-the-shelf solutions for automated composite manufacturing, are identified.

  • 32.
    Björnsson, A.
    et al.
    Linköping University, Sweden.
    Jonsson, Marie
    RISE, Swerea, SICOMP.
    Lindbäck, J. E.
    SSAB, Sweden.
    Åkermo, M.
    KTH Royal Institute of Technology, Sweden.
    Johansen, K.
    Linköping University, Sweden.
    Robot-forming of prepreg stacks - Development of equipment and methods2016In: ECCM 2016 - Proceeding of the 17th European Conference on Composite Materials, European Conference on Composite Materials, ECCM , 2016Conference paper (Refereed)
    Abstract [en]

    Within the aerospace industry the manufacturing of composite components with complex shapes, such as spars, ribs and beams are often manufactured using manual layup and forming of prepreg material. Automated processes for prepreg layup and efficient forming techniques like vacuum forming are sometimes difficult to employ to these type of products due to technical limitations. This paper describes the development of tools and the forming sequence needed to automate sequential forming of a complex shape using an industrial robot. Plane prepreg stacks are formed to the final shape using a dual-arm industrial robot equipped with rolling tools. Tests show that the developed tools and the employed sequence can be used to form stacks to the desired shape with acceptable quality.

  • 33.
    Blomdahl, Markus
    RISE, Swerea, SWECAST.
    Rekommendationer för skruvförband med pressgjutgods2005Report (Other academic)
  • 34.
    Blomqvist, Per
    et al.
    RISE, Swerea, SICOMP.
    Olsen, Hans
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Blomqvist, P.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Modelling the structural response of fibre-reinforced composites subjected to fire2014Conference paper (Refereed)
    Abstract [en]

    The present contribution details the development and implementation of dedicated material models for the finite element computation of the thermal and mechanical response of polymer compositestructures subjected to fire. The material models are developed so that mechanical and thermal properties at the ply level can be calculated from the constituent's properties, therefore allowing for a greater flexibility in architecture and reduced testing programs. The degradation of the resin during fire is predicted during the thermal analysis. Its effect, together with the effect of temperature, on the mechanical response is accounted for in the material model. The models are validated against a mini furnace experiment.

  • 35.
    Bloom, Jörgen
    RISE, Swerea, SWECAST.
    Engångskärnor i pressgjutgods2013Report (Other academic)
    Abstract [sv]

    Traditionellt har kärnor i pressgjutgods varit tillverkade av stål. Dessa stålkärnor är rörliga och dras ut ur pressgjutgodset innan gjutgodset stöts ut ur gjutverktyget. Detta innebär att formen på dessa stålkärnor har släppningsvinkel som gör dem möjliga att dra. Övriga gjutmetoder, som använder gravitationen eller låga gastryck för att få in smältan i formen, har länge använt engångskärnor av sand för att skapa håligheter i gjutgodset. Sandkärnorna faller sönder efter gjutningen vilket gör att kärnans form inte behöver begränsas av släppningsvinklar. Hitintills har sandkärnornas begränsade hållfasthet inte möjliggjort användning vid pressgjutning på grund av pressgjutmaskinernas höga inloppshastigheter och eftertryck. För utformningen av pressgjutgods vore det i många fall önskvärt att kunna använda engångskärnor. Utvecklingen går framåt med flera olika metoder för att tillverka engångskärnor som har tillräcklig hållfasthet för att tåla påfrestningar under pressgjutning. Kostnaden för att producera gjutgods med engångskärnor är i flera fall betydligt lägre än att produera samma gjutgods med gravitationsgjutning. Användning av engångskärnor kan även möjliggöra nya utformningar av gjutgods som kan medföra exempelvis nya funktioner, nytt utseende samt viktbesparingar.

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  • 36.
    Bloom, Jörgen
    RISE, Swerea, SWECAST.
    OFP för bestämning av defekter, inre renhet och grafitstruktur.2011Report (Other academic)
    Abstract [sv]

    Detta delprojekt syftar till att studera befintliga metoder för oförstörande provning (OFP) av gjutgods. Gjuterier (och dess kunder) vill lättare och bättre kunna identifiera om gjutgodset innehåller defekter eller har en oönskad grafitstruktur och därmed möjliggöra att defekta detaljer stoppas i ett tidigare skede i tillverkningskedjan än idag. OFP-metoderna skall gå att bygga in i automatiserade efterbehandlingslinor. Befintliga OFP-metoder har studerats i en litteratursökning. Sammanfattningsvis så finns det många olika OFP-metoder och utvecklingen går snabbt inom detta område. Den avancerade signalbehandling som förekommer i moderna OFP-instrument har möjliggjort både nya metoder samt att äldre metoder förses med nya presentationsutrustningar, som både förenklar handhavandet och förbättrar noggrannheten. Att skilja ut en OFP-metod som passar för undersökning av allt gjutgods låter sig inte göras. Men det finns flera intressanta utrustningar som skulle kunna användas i automatiserade övervakningsanläggningar.

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  • 37.
    Borgström, Henrik
    RISE, Swerea, SWECAST.
    Kontroll av Chunkygrafit i lösningshärdat segjärn2015Report (Other academic)
    Abstract [sv]

    Flertalet slutanvändare efterfrågar de lösningshärdade segjärnen på grund av dess fördelaktiga bearbetningsegenskaper till följd av låg hårdhetsvariation. Dessvärre ger ofta det kisel som lösningshärdar och stabiliserar ferriten uppkomst till chunkygrafit. Till projektets gjutförsök valdes den lösningshärdande legeringen EN-GJS-500-14. De ingående gjutparametrarna; Gjuttemperatur, Antimon- tillsats, Sektionstjocklek samt ympmedel identifierades som lämpliga att studera i gjutförsöken efter samråd med projektgruppen. För att ge ytterligare svar på hur gjutindustrin kan mäta samt styra uppkomsten av chunkygrafit gjordes en robusthetsanalys av förekommande analystekniker och resultat. Avslutningsvis ritades processkartor för de olika ympmedlen för att bättre visualisera effekterna av valda gjutparametrar.

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  • 38.
    Borgström, Henrik
    RISE, Swerea, SWECAST.
    Metoder för att begränsa chunkygrafit i segjärn2014Report (Other academic)
    Abstract [sv]

    I framtiden finns planer på större vindkraftsturbiner med effekter över 10 MW, vilket ställer enorma krav på segjärnets strukturella integritet om det ska vara ett ekonomiskt gångbart alternativ till stål eller andra material. Förutom övriga defekter t.ex. dross, gasporer etc. är undvikandet av oönskade grafitstrukturer centralt till att lyckas med denna utmaning. I allt tyngre gods är det avgörande hur gjutprocessen utformas och kontrolleras för att undvika de oönskade grafittyperna t.ex. chunky, Widmannstätten (”spiky”) och exploderad grafit. Av dessa grafitstrukturer brukar chunkygrafit få mest uppmärksamhet. Området med chunkygrafit framträder efter skärande bearbetning som mörka områden på ytan och är svår att detektera med hjälp av oförstörande provning, OFP. Betydelsen av Chunkygrafit är att segjärnets brottgräns minskar och ofta är lika med stäckgränsen, vilket – i princip nollar brottförlängningen samt gör materialet sprött. Därför syftar denna rapport till att ge vägledning till hur chunkygrafit kan undvikas i gjuteriprocessen.

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  • 39.
    Bregner, Anders
    RISE, Swerea, IVF.
    Swerea Lättvikt: Tekniska textilier2013Report (Other academic)
  • 40.
    Brehmer, Aron
    RISE, Swerea, SWECAST.
    Gjut- och restspänningssimulering i designarbetet del 22015Report (Other academic)
    Abstract [sv]

    Detta delprojekt handlade om att undersöka hur noggrant det går att simulera restspänningar i en gjuten komponent. Detta gjordes genom att verifiera restspänningssimuleringar med fysiska mätningar på ett gjutgods som i detta fall var cylindrar i gjutjärn. Restspänningsmätningar genomfördes med sektionering och hålborrning, både i gjutet och bearbetat tillstånd. Simuleringarna utgick från processdata som registrerades under gjutning av cylindrarna samt materialdata från simuleringsmjukvarans databas. Materialdata för formsandens konduktivitet undersöktes virtuellt för att få en god överenstämelse mellan simulerade och uppmätta data för temperaturen. Detta för att erhålla relevant temperaturhistorik för restspänningsberäkningar. Det visade sig att simuleringen hade god överenstämmelse med sektioneringsmätningar för axiell spänning medans hålborrningsmätningarna gav inbördes motstridiga resultat.

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  • 41.
    Brehmer, Aron
    et al.
    RISE, Swerea, SWECAST.
    Jidah, Sargon
    RISE, Swerea, SWECAST.
    Gjut- och restspänningssimulering i designarbetet del 12014Report (Other academic)
    Abstract [sv]

    I arbetet undersöktes hur en produkts livslängd påverkas av restspänningar och inhomogena materialegenskaper. Restspänningar finns i princip alla produkter och uppkommer till följd av tillverkningsprocessen, bearbetning och värmebehandling. Gjutna produkter uppvisar även varierande materialegenskaper orsakat av olika stelning- och svalningshastighet som följd av varierande godstjocklek. Vid dimensionering av en komponent utgår ofta konstruktörer från att materialet är spänningsfritt och har homnogena materialegenskaper vilket kan leda till felaktig dimensionering. Restspänningar i drag kan ha en negativ inverkan då de underlättar sprickbildning. Av samma orsak kan tryckspänningar ha positiv inverkan. T.ex. kan ett kritiskt fall uppstå om höga restspänningar förekommer i ett område samtidigt som det är utsatt för betydande spänning orsakad av yttre last. Med ökad kunskap om restspänningar och inhomogena materialegenskaper i komponenter kan konstruktören redan på ett tidigt stadie ta hänsyn till dessa. Det kan leda till lättare komponenter med bibehållen styrka. En arbetsmetodik togs fram där restspänningar och inhomogena materialegenskaper till följd av gjutprocessen tas med i simulering av livslängdsanalys. Resultaten från simuleringarna visar att livslängden hos komponenten varierar med avseende på utmattning om man beaktar restspänningar och varierande materialegenskaper i analyserna. För den komponent och de specifika lastfall som analyserades i det här projektet har restspänningarna liten inverkan. Däremot visar det sig att utmattningslivslängden minskar kraftigt om man tar hänsyn till varierande lokala materialegenskaper.

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  • 42.
    Brouzoulis, J.
    et al.
    Chalmers University of Technology, Sweden.
    Fagerström, M.
    Chalmers University of Technology, Sweden.
    Främby, J.
    Chalmers University of Technology, Sweden.
    Krollmann, J.
    Technische Universität München, Germany.
    Hellström, Peter
    RISE, Swerea, SICOMP.
    Modelling of propagating delaminations in textile reinforced duroplast beams by an enriched shell element formulation2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    Manufacturing and delamination testing, of textile reinforced Duroplast beams, have been performed to determine critical fracture energies in mode I, mode II and mixed mode loading. This includes values for growth initiation as well as propagation. For mode II and mixed mode loading, a large scatter in values were observed and no values corresponding to stable crack growth was obtained. Furthermore, an XFEM enriched shell element, which internally can represent multiple interlaminar cracks, have been used to simulate the DCB test. In the numerical simulation, data from the experimental tests have been used as input for a bilinear cohesive zone model. The load-displacement curve from the FE analysis shows good agreement with the corresponding measured curves, although with a somewhat higher stiffness. 

  • 43.
    Brämming, Mats
    et al.
    RISE, Swerea, MEFOS.
    Björkman, Bo
    Luleå University of Technology, Sweden.
    Samuelsson, Caisa
    Luleå University of Technology, Sweden.
    BOF Process Control and Slopping Prediction Based on Multivariate Data Analysis2016In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 87, no 3, p. 301-310Article in journal (Refereed)
    Abstract [en]

    In a complex industrial batch processes such as the top-blown BOF steelmaking process, it is a complicated task to monitor and act on the progress of several important control parameters in order to avoid an undesired process event such as "slopping" and to secure a successful batch completion such as a sufficiently low steel phosphorous content. It would, therefore, be of much help to have an automated tool, which simultaneously can interpret a large number of process variables, with the function to warn of any imminent deviation from the normal batch evolution and to predict the batch end result. One way to compute, interpret, and visualize this "batch evolution" is to apply multivariate data analysis (MVDA). At SSAB Europe's steel plant in Luleå, new BOF process control devices are installed with the purpose to investigate the possibility for developing a dynamic system for slopping prediction. A main feature of this system is steelmaking vessel vibration measurements and audiometry to estimate foam height. This paper describes and discusses the usefulness of the MVDA approach for static and dynamic slopping prediction, as well as for end-of-blow phosphorous content prediction. Multivariate data analysis (MVDA) methods have been applied on the top-blown BOF steelmaking process, with the main aim to create industrially applicable static (i.e., prior to blow), as well as dynamic in-blow batch models for predicting the slopping probability. The MVDA approach has also been investigated in regard to in-blow prediction of end-of-blow phosphorous content.

  • 44.
    Carlson, J. E.
    et al.
    Luleå University of Technology, Sweden.
    Lundin, Peter
    RISE, Swerea, KIMAB.
    Measurement of the clamping force applied by load-bearing bolts using a combination of compression and shear ultrasonic waves2015In: 2015 IEEE International Ultrasonics Symposium, IUS 2015, Institute of Electrical and Electronics Engineers Inc. , 2015Conference paper (Refereed)
    Abstract [en]

    Quantitative measurement of the clamping or tightening force of rods and bolts is important when assessing the structural integrity of various constructions. This paper shows that by using a bi-wave ultrasonic pulse-echo technique, it is possible to determine this tightening force without the need of extensive calibration prior to installing the bolts. We show that the ratio of the time-of-flight (TOF) between the transversal and the longitudinal waves changes linearly with the clamping force and that we only need to know the TOF of the unstrained bolt prior to installment. This is then demonstrated experimentally on a 1.1 m rock bolt, using pulses that propagated 6.6 m. Two different methods for estimation of the TOF ratio are evaluated.

  • 45.
    Carlson, Tony
    et al.
    RISE, Swerea, SICOMP.
    Asp, Leif E.
    RISE, Swerea, SICOMP.
    Ekermo, V.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Sellergren, P. -I
    Volvo, Sweden.
    Manufacturing of a multifunctional composite part for use in automotive applications2013In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2013, p. 6931-6939Conference paper (Refereed)
  • 46.
    Carlsson, Andreas
    RISE, Swerea, SWECAST.
    Enkla geometrier2011Report (Other academic)
    Abstract [sv]

    Trots gjutindustrins stora möjligheter att gjuta komplicerade detaljer i sandgjuten aluminium finns ännu idag problem med att gjuta de enklaste geometrier. En enkel geometri kan till exempel vara en platta, cylinder eller något som har stora plana ytor utan geometriförändringar och ofta en relativt tunn väggtjocklek (låg modul). Det finns också andra typer av enkla geometrier såsom klot eller någon annan typ av komponent med liten area i förhållande till sin volym (hög modul). För att nå kvalité i sin gjutna komponent är en grundförutsättning att använda en så ren smälta som möjligt En av de viktigaste riktlinjerna att följa är att hålla smältans hastighet låg. För aluminium är det cirka 0,3 m/s för att inte orsaka turbulens i smältan. Gjutsimulering är ett bra (och ibland nödvändigt) verktyg för att stödja och utvärdera beredningen. Med hjälp av simulering kan många av defekttyperna minimeras eller undvikas helt. En enkel platta togs fram och gjutsimulerades för att illustrera gjutfenomen. Stelningsförloppet är fundamentalt. Ett riktat stelnande där detaljen, efter inlett stelnande, riktat stelnar genom detaljen mot eventuella matare. Även en fiktiv kon simulerades och bland annat problematik med mötande smältfronter blev tydlig. Även för enkla geometrier krävs en god beredning. Följande punkter bör tas i beaktning:  Smältans hastighet bör inte överstiga 0,3 m/s och ska inte överstiga 0,5 m/s.  Orientering av gjutsystem. o Lägg gjutsystemet så den större delen av gjutgodset hamnar relativt lågt och minimera höjden. Placera öppna ytor nedåt  Delning o Placera delningsplanet så lågt som möjligt i förhållande till gjutgodset och genom den största tvärsnittsarean i gjutgodset  Matare o Undvik i första hand matare om möjligt. Följ annars anvisningar för matning  Expanderande system o Använd expanderande ingjutsystem. I ett expanderande system ökar areorna genom ingjutsystemet och håller smältans hastighet låg  Stigande fyllnad o En stigande fyllnad ger ett lugnt formfyllnadsförlopp utan onödig turbulens i smältan  Nedlopp o Nedloppet styr metalflödet genom gjutsystemet. Höjden styrs av gjutgodset och eventuell toppmatare  Inlopp o Inloppen bör sitta mot tjockare sektioner på godset. Lägg inloppen i flödesriktningen för att undvika erosion och turbulens. Flera inlopp kan användas för att minska risken för oönskade värmecentra  Skapa ett riktat stelnande och håll matarvägar öppna  Undvik stora plana horisontella ytor, luta formen vid behov  Var vaksam mot mötande smältfronter. Kan komponenten gjutas stående?  Gjutsimulera o Gjutsimulera för att göra rätt från början För övrigt bör även:  Gasinnehållet i smältan minimeras o Gjut inte med för hög temperatur o Tänk på fukten

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  • 47.
    Carlsson, Andreas
    RISE, Swerea, SWECAST.
    Gjutning och simulering av tunt gjutgods2011Report (Other academic)
    Abstract [sv]

    Energiförbrukningen i ett gjuteri har naturligt en direkt koppling till hur mycket metall som smälts för gjutprocessen. Problemet med ofullständig formfyllnad leder till att det finns en minsta väggtjocklek som kan gjutas. Faktorer eller parametrar som påverkar flytbarheten kan grovt delas in i a) metallurgiska variabler såsom kemisk sammansättning, övertemperatur/gjuttemperatur, latent värme, ytspänning, viskositet och stelningmekanism. Dessa storheter är alla kopplade till den specifika legeringen och andra delen är b) form/gjutvariabler såsom formmaterial och dess ytkarakteristik, delning och detaljplacering och förvärmning De riktlinjer som finns vid simulering av tunt gjutgods är att minst tre noder eller element ska finnas i den minsta väggtjockleken. Om det inte kan uppnås är det risk att simuleringsresultatet inte blir fysikaliskt och därmed missvisande. Fler element är (ur resultatsynpunkt) dock bara positivt. Vid gjutsimulering har följande parametrar stor påverkan på simuleringsresultatet:  Värmeövergångstalet mellan form och smälta  Formmaterialets värmeledningsförmåga  Väggfriktionen  Viskositetens temperaturberoende  Den specifika legeringens stelningskurva Vid tunnväggiga sektioner kan även små geometriska avvikelser ha stor effekt. Viktiga punkter är:  Beredningsmod; att våga utnyttja process och maskin maximalt  Variationer vid hopläggning av form, flaska och kärna  Processvariationer i black, maskindesign och krympning Gjutning av tunnväggiga komponenter ställer högre krav på gjutprocessen än traditionell gjutning. Processfönstret är betydligt snävare och även små variationer i processen kan ge stort utslag på det slutliga gjutna resultatet. Framtida arbete kan vara att trimma in gjutsimuleringsprogram mot specifika legeringar för att avgöra om skillnaden i flytbarhet mellan eutektisk legering och legering med långt stelningsintervall kan påvisas virtuellt. Undersökningar visar att skothalten har stor påverkan, hur hanteras det? Under vilka former kan måttkedjan mätas och förbättras?

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  • 48.
    Carlsson, Andreas
    RISE, Swerea, SWECAST.
    Gjutning och simulering av tunt segjärnsgjutgods2010Report (Other academic)
    Abstract [sv]

    Många segjärnskomponenter är idag överdimensionerade på grund av bristande kunskap kring hur tunt segjärngjutgods ska produceras. Idag ligger stort viktfokus inom många branscher, speciellt då inom fordonsbranschen. Då kunskapen kring att gjuta segjärnet tunt är bristfällig blir konsekvensen vanligen att byta material (till exempel aluminium) för att reducera vikt. Då förloras många av segjärnets goda mekaniska egenskaper såsom hållfasthet och brottförlängning. Den största utmaningen vid gjutning av tunt segjärnsgjutgods är att undvika karbidurskiljning (vitt stelnande) på grund av den höga stelnings- och svalningshastighet som uppkommer. Formfyllnaden blir av samma anledning också försvårad. Ett antal prov göts i en testgeometri som bestod av ett tunnväggigt rör. Proven visade olika parameters påverkan på fyllhöjden i röret. Väggtjockleken visade sig naturligt vara en av de parametrar som påverkade allra mest. Kol- och kiselhalt visade mindre effekt på fyllhöjden. Mikrostrukturen i ett antal rör studerades och det kunde ses ett samband mellan den höga stelnings- och svalningshastigheten och karbidbildning samt nodultäthet. Det noterades också att karbidbildning och nodultätheten varierar genom röret. Detta antas bero på att formmaterialet värms upp av den passerande smältan och blir mer isolerande. Det kan även bero på att foten på röret bidrar med värme till den närmaste omgivningen och därmed bromsar stelning och svalning. Provgjutningarna i röret användes som indata för att trimma in gjutsimuleringsprogrammet ProCast. Det intrimmade programmet användes sedan för att gjutsimulera projektets reella komponent, ett cylinderskydd från Indexator AB. Simuleringen visade att det skulle bli en problematisk gjutning med stor risk för kallflytningar. En provgjutning bekräftade resultatet. För att minska karbidbildningen krävs mer utredning kring hur smältans kemiska sammansättning och ympprocessen påverkar segjärnets mikrostruktur vid tunnväggig gjutning. Försök bör också göras med ökad isolation i formmaterialet för att sänka stelnings- och svalningshastigheten. Formfyllnad vid tunnväggig gjutning är idag möjlig att simulera med tillfredställande noggrannhet. Dock behövs mer kunskap kring samspelet mellan smälta och form. Gravitationsgjutning av tunna sektioner är ett relativt snabbt förlopp där värmeövergångstalet och värmeledningsförmågan hos formsanden är faktorer som påverkar i hög grad.

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  • 49.
    Carlsson, Andreas
    et al.
    RISE, Swerea, SWECAST.
    Fourlakidis, Vasilios
    RISE, Swerea, SWECAST.
    G811J – Optimering av filter2010Report (Other academic)
    Abstract [sv]

    Att använda filter har blivit en accepterad metod för att förbättra kvalitén hos gjutgods. Undersökningar visar att användning av filter kan bland annat öka skärbarheten och höja utmattningsprestandan hos gjutna komponenter. Filter har generellt två funktioner. Den första är att filtrera smältan från inneslutningar och andra oönskade partiklar. Funktion två är att bromsa smältan för att undvika höga hastigheter och därmed turbulens i smältan. För att se filtrets påverkan på gjutningen i en simulering användes ett befintligt gjutsystem med filter. Avsikten med försöken var att under identiska förhållanden prova olika filter och filterlöst gjutsystem.  Simulering med keramiskt skumfilter 10ppi  Simulering med keramiskt skumfilter 20 ppi  Simulering utan filter Fysiska försök har gjorts med Contact time metoden. Detta för att utvärdera filtrets påverkan på formfyllnadsmekanismen. På grund av mättekniska skäl blev resultaten intetsägande men metoden som sådan visar potential. Filter har påverkan på flödet då de används i en gjutsimulering. Filtret åstadkommer en trycksänkning som ger ett mer harmoniskt flöde. Det blir en tydlig skillnad då flödet betraktas över tid och i diagramform istället för momentana bilder på smältans hastighet. Metoden kan utvecklas för att bli ett snabbt och smidigt sätt att utvärdera ett gjutsystem med avseende på smälthastighet och turbulens vid kritiska tvärsnitt såsom änden på ingjutkanaler etc. Framtida arbete är  Nya försök med contact time metoden för att ytterligare bekräfta filtrets påverkan på flödet  Undersöka andra metoder för att via simulering utvärdera filter  Andra försök för att försöka fastställa filtrets påverkan på gjutsystemet

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  • 50.
    Carlsson, Andreas
    et al.
    RISE, Swerea, SWECAST.
    Fourlakidis, Vasilios
    RISE, Swerea, SWECAST.
    Optimering av filter2011Report (Other academic)
    Abstract [sv]

    Att använda filter har blivit en accepterad metod för att förbättra kvalitén hos gjutgods. Undersökningar visar att användning av filter kan bland annat öka skärbarheten och höja utmattningsprestandan hos gjutna komponenter. Filter har generellt två funktioner. Den första är att filtrera smältan från inneslutningar och andra oönskade partiklar. Funktion två är att bromsa smältan för att undvika höga hastigheter och därmed turbulens i smältan. För att se filtrets påverkan på gjutningen i en simulering användes ett befintligt gjutsystem med filter. Avsikten med försöken var att under identiska förhållanden prova olika filter och filterlöst gjutsystem.  Simulering med keramiskt skumfilter 10ppi  Simulering med keramiskt skumfilter 20 ppi  Simulering utan filter Fysiska försök har gjorts med Contact time metoden. Detta för att utvärdera filtrets påverkan på formfyllnadsmekanismen. På grund av mättekniska skäl blev resultaten intetsägande men metoden som sådan visar potential. Filter har påverkan på flödet då de används i en gjutsimulering. Filtret åstadkommer en trycksänkning som ger ett mer harmoniskt flöde. Det blir en tydlig skillnad då flödet betraktas över tid och i diagramform istället för momentana bilder på smältans hastighet. Metoden kan utvecklas för att bli ett snabbt och smidigt sätt att utvärdera ett gjutsystem med avseende på smälthastighet och turbulens vid kritiska tvärsnitt såsom änden på ingjutkanaler etc. Framtida arbete är  Nya försök med contact time metoden för att ytterligare bekräfta filtrets påverkan på flödet  Undersöka andra metoder för att via simulering utvärdera filter  Andra försök för att försöka fastställa filtrets påverkan på gjutsystemet

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