oru.sePublikasjoner
Endre søk
Begrens søket
1234567 101 - 150 of 1570
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 101.
    Arapan, S.
    et al.
    IT4Innovations, VSB-Technical University of Ostrava, Ostrava-Poruba, Czech Republic; ICCRAM, International Research Center in Critical Raw Materials and Advanced Industrial Technologies, University of Burgos, Burgos, Spain.
    Nieves, P.
    ICCRAM, International Research Center in Critical Raw Materials and Advanced Industrial Technologies, University of Burgos, Burgos, Spain.
    Cuesta-Lopez, S.
    ICCRAM, International Research Center in Critical Raw Materials and Advanced Industrial Technologies, University of Burgos, Burgos, Spain; ICAMCyL, International Center for Advanced Materials and Raw Materials of Castilla y Léon, Léon, Spain.
    Gusenbauer, M.
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Oezelt, H.
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Schrefl, T.
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Delczeg-Czirjak, E. K.
    Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Uppsala, Sweden.
    Herper, H. C.
    Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Uppsala, Sweden.
    Eriksson, Olle
    Örebro universitet, Institutionen för naturvetenskap och teknik. Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Uppsala, Sweden.
    Influence of antiphase boundary of the MnAl tau-phase on the energy product2019Inngår i: Physical Review Materials, ISSN 2475-9953, Vol. 3, nr 6, artikkel-id 064412Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we use a multiscale approach to describe a realistic model of a permanent magnet based on MnAl tau-phase and elucidate how the antiphase boundary defects present in this material affect the energy product. We show how the extrinsic properties of a microstructure depend on the intrinsic properties of a structure with defects by performing micromagnetic simulations. For an accurate estimation of the energy product of a realistic permanent magnet based on the MnAl tau-phase with antiphase boundaries, we quantify exchange interaction strength across the antiphase boundary defect with a simple approach derived from first-principles calculations. These two types of calculations, performed at different scales, are linked via atomistic spin-dynamics simulations.

  • 102.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Sornil, Ohm
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    A broadcast based random query gossip algorithm for resource search in non-DHT mobile Peer-to-Peer networks2017Inngår i: Diànnǎo xuékān, ISSN 1991-1599, Vol. 28, nr 1, s. 209-223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a resource discovery scheme for decentralized non-DHT Mobile Peer-to-Peer (MP2P) networks. In a mobile environment, the energy of mobile device is very critical. The aim of the proposed technique is to reduce the network overhead, lower battery power consumption and minimize query delay while improving the chance to resolve the query at every successive stage. Peer-to-Peer applications have gained a lot of attention in past years due to its decentralized nature. Resource searching algorithms are one of the major focuses of P2P network. Mobile Ad hoc Network (MANET) with its changing topology further poses additional challenges and thus increasing the search effort. Methods like flooding, random walk and probabilistic forwarding techniques are good candidates to run over such dynamic network. In this work, we study the flooding, random walk and gossip based resource discovery protocols on a P2P Mobile Ad hoc Network. We observed that the classic gossip algorithm does not work well under MANET as in the case of a wired network. We focus to improve the algorithm to suit and work better under such dynamic network scenario. The proposed system presents a light weight resource discovery design to suit the mobility requirement of ad hoc networks to optimize the search performance while at the same time minimize the extra usage of mobile and network resources. For quick and energy efficient search scheme, we explore a novel addressed jumping approach. Our algorithm is entirely distributed, and hence will scale well even to the growing size of the network. The efficiency of our proposed algorithm is validated through extensive NS-2 simulations. The results show that our proposed scheme gives better performance than the widely used techniques. We also validate through statistical hypothesis testing of simulation data.

  • 103.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Sornil, Ohm
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Minimizing Redundant Messages and Improving Search Efficiency under Highly Dynamic Mobile P2P Network2016Inngår i: Journal of Engineering Science and Technology Review, ISSN 1791-9320, E-ISSN 1791-2377, Vol. 9, nr 1, s. 23-35Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Resource Searching is one of the key functional tasks in large complex networks. With the P2P architecture, millions of peers connect together instantly building a communication pattern. Searching in mobile networks faces additional limitations and challenges. Flooding technique can cope up with the churn and searches aggressively by visiting almost all the nodes. But it exponentially increases the network traffic and thus does not scale well. Further the duplicated query messages consume extra battery power and network bandwidth. The blind flooding also suffers from long delay problem in P2P networks. In this paper, we propose optimal density based flooding resource discovery schemes. Our first model takes into account local graph topology information to supplement the resource discovery process while in our extended version we also consider the neighboring node topology information along with the local node information to further effectively use the mobile and network resources. Our proposed method reduces collision at the same time minimizes effect of redundant messages and failures. Overall the methods reduce network overhead, battery power consumption, query delay, routing load, MAC load and bandwidth usage while also achieving good success rate in comparison to the other techniques. We also perform a comprehensive analysis of the resource discovery schemes to verify the impact of varying node speed and different network conditions.

  • 104.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, School of Applied Statistics, National Institute of Development Administration, Bangkok, Thailand.
    Sornil, Ohm
    Department of Computer Science, School of Applied Statistics, National Institute of Development Administration, Bangkok, Thailand.
    Reducing Routing Overhead in random walk protocol under MP2P Network2016Inngår i: International Journal of Electrical and Computer Engineering, ISSN 2088-8708, Vol. 6, nr 6, s. 3121-3130Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to network dynamics in self-organizing networks the resource discovery effort increases. To discover objects in unstructured peer-to-peer network, peers rely on traditional methods like flooding, random walk and probabilistic forwarding methods. With inadequate knowledge of paths, the peers have to flood the query message which creates incredible network traffic and overhead. Many of the previous works based on random walk were done in wired network. In this context random walk was better than flooding. But under MANETs random walk approach behaved differently increasing the overhead, due to frequent link failures incurred by mobility. Decentralized applications based on peer-to-peer computing are best candidates to run over such dynamic network. Issues of P2P service discovery in wired networks have been well addressed in several earlier works. This article evaluates the performance of random walk based resource discovery protocol over P2P Mobile Adhoc Network (MP2P) and suggests an improved scheme to suit MANET. Our version reduces the network overhead, lowers the battery power consumption, minimizes the query delay while providing equally good success rate. The protocol is validated through extensive NS-2 simulations. It is clear from the results that our proposed scheme is an alternative to the existing ones for such highly dynamic mobile network scenario.

  • 105.
    Arvidsson, Erik
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Energiförbrukning för putsade, odränerade träregelväggar i fuktigt respektive torrt tillstånd2009Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    In recent years, moisture damages have been noticed in rendered, undrained stud walls. The design is built on the principle one-stage tightening which means that there is no air gap in the construction. The damages have occurred when water has permeated through the rendering in leaking connections and fittings for windows, doors, canopies, balconies, terraces and awnings. Behind the plaster carrier, which consists of either polystyrene or rigid mineral wool, plasterboard has often been used as a wind protection barrier. In many cases the wind protection barrier and the underlying wooden studs have been exposed to mould and in some cases even rot. It has been shown that damp in the structure is difficult to dry out.

    The aim of the thesis has been to examine how the energy consumption is affected when this type of construction is damp, partly because energy is required to dry up damp, partly because the insulation ability for a material decreases when it is affected by moisture.

    Previous research and relevant literature has been used in this thesis, to provide: A comprehensive picture of the problem, an explanation for the calculations used and an understanding of the conclusions drawn.

    The energy consumption has been calculated for 1 m2 wall area on two types of wall designs. The calculations have been performed in both dry and damp condition. To calculate the energy consumption in damp condition, three different types of calculation models have been used in three different ways. Since no measurements have been made, the calculations are to some extent based on assumed values.

    The amount of damp that have entered the structure has, according to the calculation models used, been shown to produce small differences in energy consumption compared to the dry structure. The main problem for these types of walls seems instead to be the growth of microorganisms. Nevertheless, the microorganisms seem not to have affected the indoor environment in any significant manner.

  • 106.
    Arvidsson, Erik
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Larsson, Tord
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Stridh, Göran
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Energiförluster i partiellt fuktiga enstegstätade ytterväggskonstruktioner: tema: fasader och fönster2009Inngår i: Bygg & teknik, ISSN 0281-658X, nr 8, s. 28-32Artikkel i tidsskrift (Annet vitenskapelig)
  • 107.
    Arén, Björn
    Örebro universitet, Institutionen för teknik.
    Die Stresses in the compaction of powders: experiments and analysis2004Konferansepaper (Fagfellevurdert)
  • 108.
    Arén, Björn
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Dimensionering efter hållfasthet av olika slag2009Inngår i: Uppfinnaren & konstruktören, ISSN 0284-9682, nr 5, s. 32-34Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 109.
    Arén, Björn
    Örebro universitet, Institutionen för teknik.
    Dimensioning of dies for the compaction of shaped PM-parts2003Konferansepaper (Fagfellevurdert)
  • 110.
    Arén, Björn
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Utveckling - är att se, söka och förverkliga: kursbok i produktutveckling2010 (oppl. 1)Bok (Annet vitenskapelig)
  • 111.
    Asaad Sharif Elemara, Hadil
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    GRUNDLÄGGNINGSMETODER-VAL AV GRUNDLÄGGNINGSMETOD FÖR SMÅHUS I ÖREBRO LÄN2012Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Husgrunder stödjer hela hus och ska vara stadiga nog för att ta upp husets vikt och bära byggnaden i

    många år utan att drabbas av problem orsakade av bland annat fukt och tjäle. Det finns tre

    grundkonstruktionstyper som tas upp i detta arbete. Dessa är: platta på mark, krypgrund och

    plintgrund.

    Syftet med arbetet är att undersöka konstruktion och funktion för de tre grundkonstruktionerna.

    Arbetet redovisar också vilka grunder som är förekommande vid nybyggnation av småhus i Örebro

    län, samt hur olika aktörer inom byggbranschen motiverar sina val med avseende på risken för

    fuktrelaterade problem.

    Inom detta examensarbete redovisas resultat från intervjuer med ett antal olika byggnadsaktörer

    som bygger med olika typer av grundkonstruktioner. Information har samlats in genom intervjuer

    med sakkunniga samt egen teorifördjupning i litteratur för grundkonstruktioner. Utifrån syftet med

    arbetet har teorin och resultaten från intervjuerna sammanställts.

    Platta på mark med underliggande isolering är den grundkonstruktion som framförallt väljs vid val

    av grundkonstruktion för nybyggnationer av småhus i Örebro län. Aktörerna upplever att denna

    konstruktion har många fördelar i jämförelse med de andra konstruktionerna: krypgrund och

    plintgrund.

  • 112.
    Asadi, Sahar
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Badica, Costin
    University of Craiova, Craiova, Romania.
    Comes, Tina
    Karslruhe Institute of Technology, Karslruhe, Germany.
    Conrado, Claudine
    Thales Research and Technology, Delft, The Netherlands.
    Evers, Vanessa
    University of Amsterdam, Amsterdam, The Netherlands.
    Groen, Frans
    University of Amsterdam, Amsterdam, The Netherlands.
    Illie, Sorin
    University of Craiova, Craiova, Romania.
    Steen Jensen, Jan
    Danish Emergency Management Agency (DEMA), Birkerød, Denmark.
    Lilienthal, Achim J.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Milan, Bianca
    DCMR, Delft, The Netherlands.
    Neidhart, Thomas
    Space Applications Services, Zaventem, Belgium.
    Nieuwenhuis, Kees
    Thales Research and Technology, Delft, The Netherlands.
    Pashami, Sepideh
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Pavlin, Gregor
    Thales Research and Technology, Delft, The Netherlands.
    Pehrsson, Jan
    Prolog Development Center, Brøndby Copenhagen, Denmark.
    Pinchuk, Rani
    Space Applications and Services, Zaventem, Belgium.
    Scafes, Mihnea
    University of Craiova, Craiova, Romania.
    Schou-Jensen, Leo
    DCMR, Brøndby Copenhagen, Denmark.
    Schultmann, Frank
    Karslruhe Institute of Technology, Karlsruhe, Germany.
    Wijngaards, Niek
    Thales Research and Technology, Delft, the Netherlands.
    ICT solutions supporting collaborative information acquisition, situation assessment and decision making in contemporary environmental management problems: the DIADEM approach2011Inngår i: Proceedings of the 25th EnviroInfo Conference "Environmental Informatics", Herzogenrath: Shaker Verlag, 2011, s. 920-931Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a framework of ICT solutions developed in the EU research project DIADEM that supports environmental management with an enhanced capacity to assess population exposure and health risks, to alert relevant groups and to organize efficient response. The emphasis is on advanced solutions which are economically feasible and maximally exploit the existing communication, computing and sensing resources. This approach enables efficient situation assessment in complex environmental management problems by exploiting relevant information obtained from citizens via the standard communication infrastructure as well as heterogeneous data acquired through dedicated sensing systems. This is achieved through a combination of (i) advanced approaches to gas detection and gas distribution modelling, (ii) a novel service-oriented approach supporting seamless integration of human-based and automated reasoning processes in large-scale collaborative sense making processes and (iii) solutions combining Multi-Criteria Decision Analysis, Scenario-Based Reasoning and advanced human-machine interfaces. This paper presents the basic principles of the DIADEM solutions, explains how different techniques are combined to a coherent decision support system and briefly discusses evaluation principles and activities in the DIADEM project.

  • 113.
    Asadi, Sahar
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Pashami, Sepideh
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    TD Kernel DM+V: time-dependent statistical gas distribution modelling on simulated measurements2011Inngår i: Olfaction and Electronic Nose: proceedings of the 14th International Symposium on Olfaction and Electronic Nose (ISOEN) / [ed] Perena Gouma, Springer Science+Business Media B.V., 2011, s. 281-282Konferansepaper (Fagfellevurdert)
    Abstract [en]

    To study gas dispersion, several statistical gas distribution modelling approaches have been proposed recently. A crucial assumption in these approaches is that gas distribution models are learned from measurements that are generated by a time-invariant random process. While a time-independent random process can capture certain fluctuations in the gas distribution, more accurate models can be obtained by modelling changes in the random process over time. In this work we propose a time-scale parameter that relates the age of measurements to their validity for building the gas distribution model in a recency function. The parameters of the recency function define a time-scale and can be learned. The time-scale represents a compromise between two conflicting requirements for obtaining accurate gas distribution models: using as many measurements as possible and using only very recent measurements. We have studied several recency functions in a time-dependent extension of the Kernel DM+V algorithm (TD Kernel DM+V). Based on real-world experiments and simulations of gas dispersal (presented in this paper) we demonstrate that TD Kernel DM+V improves the obtained gas distribution models in dynamic situations. This represents an important step towards statistical modelling of evolving gas distributions.

  • 114.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    3D Metal Printing from an Industrial Perspective: Product Design, Production and Business Models2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper summarizes the current position of 3D metal printing/additive manufacturing (henceforth called 3D metal printing) from an industrial perspective. The new possibilities to design the part differently simply because the new shape can be produced and which provides benefits with respect to improved material utilization degree, reduced weight, size etc. are addressed in this paper. Different types of generative design concepts such as form synthesis, topology optimization and lattice and surface optimization are exemplified. Low volume production by 3D metal printing is discussed. High volume production by 3D metal printing of manufacturing tools and dies is described.

    Tool & die production is an important phase in the development of new components/product models. This phase determines both the lead time (Time-To-Production/-Market) and the size of the investments required to start the production. The lead time for the production of tools and dies for a new car body is currently about 12 months and needs to be reduced 40% by 2020. The lead time for injection molds for small and large series production must be reduced to 10 days and 4 weeks respectively. Lead time and cost-efficient metallic tools can be provided by 3D metal printing. This paper focuses on tools and dies for the manufacture of sheet metal & plastic components for the engineering, automotive and furniture industries. The paper includes Powder Bed Fusion (PBF). Digitalization through virtual tool & die design and optimization of the tool & die production combined with the PBF´s digital essence provides greater flexibility, better efficiency, tremendous speed, improved sustainability and increased global competitiveness.

    3D metal printing is expected to result in several changes in the supplier chain and generate new business models. The present paper describes some of the changes 3D metal printing has led to and is expected to result in within the engineering and automotive industry in Europe during the coming years.

  • 115.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    3D Metal Printing from an Industrial Perspective: Product Examples, Production and Business Models2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper summarizes the current position of 3D metal printing/additive manufacturing (henceforth called 3D metal printing) by the so-called Powder Bed Fusion (PBF) from an industrial perspective, particularly in Sweden.

    The new possibilities to design the part differently simply because the new shape can be produced and which provides benefits with respect to improved material utilization degree, reduced weight, size etc. are addressed in this paper.

    Tool & die production is an important phase in the development of new components/product models. This phase determines both the lead time (Time-To-Production/‐Market) and the size of the investments required to start the production. The lead time for the production of tools and dies for a new car body is currently about 12 months and needs to be reduced 40% by 2020. The lead time for injection molds for small and large series production must be reduced to 10 days and 4 weeks respectively. Lead time and cost-efficient metallic tools can be provided by 3D metal printing. This paper focuses on tools and dies for the manufacture of sheet metal & plastic components for the engineering and automotive industries.

    Digitalization through virtual tool & die design and optimization of the tool & die production combined with the PBF´s digital essence provides greater flexibility, better efficiency, tremendous speed, improved sustainability and increased global competitiveness.

    3D metal printing is expected to result in several changes in the supplier chain and generate new business models. The present paper describes some of the changes 3D metal printing has led to and is expected to result in within the engineering and automotive industry during the coming years.

  • 116.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    3D Metal Printing of Industrial Tools & Dies2019Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Tool & die production is an important phase in the development of new components/product models. This phase determines both the lead time (Time-To-Production/-Market) and the size of the investments required to start the production. This paper is focused on Powder Bed Fusion (PBF) and summarizes the current position of 3D metal printing/additive manufacturing (henceforth called 3D metal printing)of industrial tools & dies. It also exhibits the new possibilities to design the tool/die differently simply because the new shape can be produced. Different types of generative design concepts such as form synthesis, topology optimization and lattice and surface optimization are exemplified. The paper exemplifies business cases, the shorter lead times, the associated improved material utilization degree, reduced weight,etc. Low volume production by 3D metal printing is discussed. High volume production by 3D metal printing of manufacturing tools and dies is described. The paper exhibits some examples of digitalization through virtual tool & die design and optimization of the tool& die production and how it provides greater flexibility, better efficiency, tremendous speed, improved sustainability and increased global competitiveness. 3D metal printing is expected to result in several changes in the supplier chain and generate new business models. The present paper describes some of the changes 3D metal printing has led to and is expected to result in within the engineering and automotive industry in Europe during the coming years.

  • 117.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    3D Metal Printing of Production Tools & Dies2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    3D metal printing is of great interest for manufacturing of tools and dies for high volume production. It is possible to accomplish lead time reduction, tool and die weight saving, improved cycle time etc. The presentation deals primarily with Powder Bed Fusion as 3D printing method and describes 3D metal printing of tools & dies both scientifically and from an industrialization perspective. The presentation shows how far we have come in industrialization of 3D metal printing of tools & dies and what needs to be done to include 3D metal printing in the existing industrial systems and infrastructure.

  • 118.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    3D Printing / Additative Manufacturing from Product Creator and Tool Maker Perspectives in the Automotive Industry2016Konferansepaper (Annet vitenskapelig)
  • 119.
    Asnafi, Nader
    VA Automotive AB, Hässleholm, Sweden .
    3D-printning från produktskapares och verktygsmakares perspektiv2015Konferansepaper (Annet vitenskapelig)
  • 120.
    Asnafi, Nader
    Sapa Technology, Finspång (and Vetlanda), Sweden.
    Analytical modelling of the forces and pressures required in hydropiercing2000Rapport (Annet vitenskapelig)
  • 121.
    Asnafi, Nader
    Volvo Car Components Corporation/Industrial Development Centre, Olofström, Sweden.
    Analytical modelling of tube hydroforming1999Inngår i: Thin-walled structures, ISSN 0263-8231, E-ISSN 1879-3223, Vol. 34, nr 4, s. 295-330Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The automotive industry has shown a growing interest in tube hydroforming during the past years. The advantages of hydroforming (less thinning, a more efficient manufacturing process etc.) can, for instance, be combined with the high strength of extra high strength steels, which are usually less formable, to produce structural automotive components which exhibit lower weight and improved service performance. Design and production of tubular components require knowledge about tube material behaviour and tribological effects during hydroforming and how the hydroforming operation itself should be controlled. These issues are studied analytically in the present paper. Hydroforming consists of free forming and calibration. Only the so-called free forming is treated here. The analytical models constructed in this paper are used to show what the limits are during the free forming, how different material and process parameters influence the loading path and the forming result, and what an experimental investigation into hydroforming should focus on. The present study was a part of a larger investigation, in which finite-element simulations and experiments were also conducted. The results of these simulations and experiments will be accounted for in coming papers.

  • 122.
    Asnafi, Nader
    Volvo Car Corporation, Göteborg (and Olofström), Sweden.
    Automotive Tools & Dies - Volvo Cars Perspective2007Konferansepaper (Annet vitenskapelig)
  • 123.
    Asnafi, Nader
    Sapa Technology, Finspång (and Vetlanda), Sweden .
    Automotive Tubular Hydroforming: Fundmentals and Industrial Practice2000Konferansepaper (Annet vitenskapelig)
  • 124.
    Asnafi, Nader
    VA Automotive AB, Hässleholm, Sweden .
    Automotive/Car Body Stamping Tools & dies: 3D Printing Offers Shorter Lead Time and Reasonable Costs2016Konferansepaper (Annet vitenskapelig)
  • 125.
    Asnafi, Nader
    Jönköping University, Jönköping, Sweden .
    Development of Sustainable Products and Manufacturing/Production2014Konferansepaper (Annet vitenskapelig)
  • 126.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Digitalization of the Swedish Industry2018Konferansepaper (Fagfellevurdert)
  • 127.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Digitalization of the Swedish Industry2018Konferansepaper (Fagfellevurdert)
  • 128.
    Asnafi, Nader
    Luleå University of Technology, Luleå, Sweden .
    Formbarhet under dragpressning, sträckpressning och bockning samt egenskaper efter formning av aluminiumplåt1988Rapport (Annet vitenskapelig)
  • 129.
    Asnafi, Nader
    Volvo Car Corporation, Göteborg (and Olofström), Sweden .
    Forming of Aluminium2002Konferansepaper (Annet vitenskapelig)
  • 130.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    Hydroformability of Extra High Strength Steels in Structural Tubular Applications: an Analysis based on Literature Survey1997Rapport (Annet vitenskapelig)
  • 131.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Improved Lightweight Manufacturing Flexibility by Stamping of Selectively Laser Heat Treated Boron Steel Sheet2016Konferansepaper (Annet vitenskapelig)
  • 132.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Innovative Lead Time and Cost Efficient Tools and Dies for Lightweight Autobody Components2016Konferansepaper (Annet vitenskapelig)
  • 133.
    Asnafi, Nader
    Uddeholms AB, Hagfors, Sweden .
    Kunddriven produktutveckling på en varierad marknad för global framgång2012Konferansepaper (Annet vitenskapelig)
  • 134.
    Asnafi, Nader
    Volvo Car Corporation, Göteborg (and Olofström), Sweden .
    Manufacturing the car body of tomorrow2002Konferansepaper (Annet vitenskapelig)
  • 135.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Metal Additive Manufacturing – State of the Art 2020: A special issue of Metals2020Collection/Antologi (Fagfellevurdert)
    Abstract [en]

    Additive manufacturing (AM), more popularly known as 3D printing, comprises a group of technologies used to produce objects through the addition (rather than removal) of material. AM is used in many industries—aerospace and defense, automotive, consumer products, industrial products, medical devices, and architecture. AM is transforming the industry, and this industrial transformation is expected to become more comprehensive and reach a higher pace during the coming years.

    Additive manufacturing of metal components with virtually no geometric limitations has enabled new product design options and opportunities, increased product performance, shorter cycle time in part production, total cost reduction, shortened lead time, improved material efficiency, more sustainable products and processes, full circularity in the economy, and new revenue streams.

    This Special Issue of Metals focuses on metal additive manufacturing with respect to the topics mentioned below (please see the Keywords/Topics below). The papers presented in this Special Issue give an account of the 2020 scientific, technological, and industrial state of the art for metal additive manufacturing from different perspectives (see the Keywords/Topics below). Your contribution to this 2020 account is highly valuable and appreciated. 

    The submitted contribution should address metal additive manufacturing with respect to one or several of the following topics:

    • Business models and engineering
    • Product/component design (including generative design, topology optimization, lattice and surface optimization, etc.)
    • Industrial applications (aerospace, defense, automotive, consumer, medical, and industrial products, etc.)
    • Material and process design and engineering
    • New materials
    • Powder production and characterization
    • Systems and equipment engineering
    • Post-processing
    • Process control and optimization and quality assurance

  • 136.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Metal Additive Manufacturing/3D Metal Printing in the Circular Economy2018Konferansepaper (Fagfellevurdert)
  • 137.
    Asnafi, Nader
    Volvo Car Corporation, Göteborg (and Olofström), Sweden .
    Nya material och processer vid framtagning av lättviktskarosser2004Konferansepaper (Annet vitenskapelig)
  • 138.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden .
    On Prediction of the Yield Strength of Pressed Panels by Using the Tensile Behaviour of the Virgin Material1992Konferansepaper (Annet vitenskapelig)
  • 139.
    Asnafi, Nader
    Gränges Technology, Finspång, Sweden.
    On springback of double-curved autobody panels2001Inngår i: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 43, nr 1, s. 5-37Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The springback of double curved autobody panels is studied theoretically and experimentally. Both steel and aluminum sheets are included in this investigation. The obtained results show that the springback is decreased with increasing binder force, increasing curvature, increasing sheet thickness and decreasing yield strength. This paper comprises also a discussion on the plastic strains and their influence on the springback.

  • 140.
    Asnafi, Nader
    Industrial Development Center/Volvo Cars Body Components, Olofström, Sweden .
    On Springback of Double-Curved Autobody Panels1998Inngår i: Proceedings, working groups meeting - IDDRG, International Deep Drawing Research Group: Genval, Benelux, June 15 - 16, 1998, 1998Konferansepaper (Annet vitenskapelig)
  • 141.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    On Springback of Double-Curved Autobody Panels, Part I: Theoretical Treatment1996Rapport (Annet vitenskapelig)
  • 142.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    On Springback of Double-Curved Autobody Panels, Part II: Experimental Analysis1996Rapport (Annet vitenskapelig)
  • 143.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden .
    On strength, stiffness and dent resistance of car body panels1995Inngår i: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 49, nr 1-2, s. 13-31Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There are cases in which practitioners wish to be able to predict the properties of a panel, should they replace one material by another. In this study, the yield strength, stiffness and dent resistance of double-curvature car body panels are treated both theoretically and experimentally. The results of the investigation show that the above-mentioned properties of a pressed panel can be predicted provided that the magnitude of the principal surface strains and the magnitude of the panel radii at the panel centre are known.

  • 144.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    On Strength, Stiffness and Dent Resistance of Car Body Panels1993Rapport (Annet vitenskapelig)
  • 145.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    On Strength, Stiffness and Dent Resistance of Car Body Panels1993Konferansepaper (Annet vitenskapelig)
  • 146.
    Asnafi, Nader
    Gränges Technology, Finspång, Sweden.
    On stretch and shrink flanging of sheet aluminium by fluid forming1999Inngår i: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 96, nr 1-3, s. 198-214Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this investigation, vertical stretch and shrink flanging of sheet aluminium by fluid forming are studied experimentally and theoretically. The theoretical part comprises both analytical modelling and finite-element simulations.

    The fracture limit in stretch flanging is determined by the plastic strain ratio, the strain hardening exponent, and the uniform strain. The greater the magnitude of these parameters, the greater will be the fracture limit.

    The maximum applied pressure determines the ’wrinkling’ limit in shrink flanging by fluid forming. The greater is this pressure, the greater ’wrinkling’ limit. This limit is certainly several times greater in magnitude than that in shrink flanging by conventional tools (a rigid punch and die).

  • 147.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden.
    On Stretch and Shrink Flanging of Sheet Aluminium by Fluid Forming1996Rapport (Annet vitenskapelig)
  • 148.
    Asnafi, Nader
    Industrial Development Center/Volvo Cars Body Components, Olofström, Sweden .
    On Stretch and Shrink Flanging of Sheet Aluminium by Fluid Forming1998Inngår i: Proceedings, working groups meeting - IDDRG, International Deep Drawing Research Group: Genval, Benelux, June 15 - 16, 1998, 1998Konferansepaper (Annet vitenskapelig)
  • 149.
    Asnafi, Nader
    Industrial Development Centre, Olofström, Sweden.
    On tool stresses in cold heading of fasteners1999Inngår i: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 6, nr 5, s. 321-335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this investigation, attention was focused on the tool stresses that emerge during manufacturing of fasteners. These stresses were studied both experimentally and theoretically. The theoretical part comprised finite-element simulation. This simulation showed that the zone at the die insert profile radius is so heavily loaded that plastic deformation is initiated in this region. In the experimental part, the emerging strains were measured in the region close to the interface between the die insert and the stress ring. The correspondence is good between the theoretical and experimental strains in this region. In spite of this and although 20 fasteners were cold-forged, the die insert did not fracture. Forming at production facilities showed that the die insert cracked after 9080 parts were produced. The results obtained in this investigation and the test conducted at production facilities indicate that high cycle fatigue, and not monotomic rupture, is the main cause of tool fracture in practice.

  • 150.
    Asnafi, Nader
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Proceedings of the 2nd International Conference on Material Engineering and Advanced Manufacturing Technology (MEAMT 2018)2018Konferanseproceedings (Fagfellevurdert)
1234567 101 - 150 of 1570
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf