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  • 51. Hedberg, Claes
    et al.
    Rudenko, Oleg
    Pulse response of a nonlinear layer2001In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 110, no 5, p. 2340-2350Article in journal (Refereed)
    Abstract [en]

    A simple analytical theory is developed for the description of non-steady state response of a thin nonlinear layer, which differs markedly in its linear properties from the surrounding medium. Such a layer can model the behavior of real inhomogeneities like a cloud of gas bubbles in a liquid, a crack or split plane in a solid, or the contact between two slightly tighted rough surfaces. Both weakly nonlinear pulse and harmonic responses are calculated and the general properties of the spectral and temporal structure of the scattered field are discussed. The exact strongly nonlinear solutions are derived for a special type of stress-strain relationship corresponding to the behavior of real condensed media under strong load. Profiles and spectra shown are in conformity with experimental results. The pulse response on the short delta-pulse shaped incident wave is calculated for arbitrary nonlinear properties of the layer. The possibilities to apply the sets of data on measured characteristics of pulse response in the solution of inverse problems are briefly discussed.

  • 52. Jönsson, Anders
    Modelling, Simulation and Experimental Investigation of a Rammer Compactor Machine2001Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This licentiate thesis considers the modelling, simulation and experimental investigation of a rammer compactor machine. The purpose is to develop an efficient and verified method for simulation of rammer compactor machines to be used in the product development process. The experience gained through this work is also intended to be useful for studying other types of dynamic compactor machines. Rammer compactor machines perform impact soil compaction. This is more efficient than static compaction. The machines are often used in places where a high degree of compaction is needed, and where the space for operation is limited. The complexity of this type of machine makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for predicting the dynamic behaviour of the machine. To be useful for optimisation the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner: experimental investigations are used to verify theoretical models and simulations; and theoretical models and simulations are used to design good experiments. This Complete Approach concept enables better decisions to be made earlier on in the development process, resulting in a decrease in time-to-market and improved quality. In this thesis, the Complete Approach concept is applied to a rammer soil compactor machine. An introductory iteration is described. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should prove useful in introductory optimisation studies. The thesis discusses reasons for the remaining discrepancy and suggests improvements in both the theoretical model and the experimental set-up for future iterations.

  • 53. Jönsson, Anders
    et al.
    Bathelt, Jens
    Broman, Göran
    Interacting with real time simulations – virtual reality in industry applications2003Conference paper (Refereed)
    Abstract [en]

    Modern manufacturing machines are highly multidisciplinary, and with demands on short time-to-market, product development based on traditional prototype testing has become impractical. By using virtual models, it is possible to test large numbers of variants and optimise the product with the aid of a minimum of physical prototypes. Due to the immense development of software and hardware for simulation and visualisation it should today be possible also for small and medium sized enterprises to use methods that just few years ago were too expensive and complicated. There is however still a great need for building knowledge and compe-tence. This work is an early step in a project aiming at a virtual water jet cutting machine to be used by the industrial partner for optimisation during the development process. The possibility of performing real-time simulations of this machine in a virtual environment, using a normal PC and commercial software, will be in-vestigated. Initially strongly simplified models of the system components are used and the focus is on the overall system model and the interaction between the operator and the virtual machine. It is shown that real-time interaction is possible with this system and with the obtained flexibility of the overall virtual model it should be easy to include more realistic component models for improved accuracy in future work. Preliminary results indicate however that to include, for example, flexibility within the mechanic structure, component modelling will be delicate. These models must describe relevant characteristics accurately enough while still being computationally effective enough for real-time interaction and systems optimisation to be possible. This will probably be a challenge in the continuation of the project, even with an expected continued strong devel-opment of computer capacity.

  • 54. Jönsson, Anders
    et al.
    Broman, Göran
    Experimental Investigation of a Rammer Soil Compactor Machine on Linear Spring Foundation2001Conference paper (Refereed)
    Abstract [en]

    Rammer compactor machines perform impact soil compaction, which is very efficient compared to static compaction. They are often used in places where a high degree of compaction is needed and the space for operation is limited. The complexity of this machine type makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for prediction of the dynamic behaviour of the machine. To be useful for optimisation as design parameters are changed during product development the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner. Experimental investigations are used to verify theoretical models and simulations. Theoretical models and simulations are used to design good experiments. This Complete Approach concept makes better decisions possible earlier in the development process, resulting in decreased time to market and improved quality. In this paper the Complete Approach concept is described. It is applied on a rammer soil compactor machine. An introductory iteration, with emphasis on the experimental part, is described. In the experimental set-up the rammer foot is attached to a linear spring foundation. This eliminates uncertainties related to soil modelling and makes a check of the model of the machine itself possible. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should be useful for introductory optimisation studies. Reasons for the discrepancy are discussed and suggestions for improvements of both the theoretical model and the experimental set-up in coming iterations are given.

  • 55. Jönsson, Anders
    et al.
    Broman, Göran
    Engström, Anders
    Modelling of a Soil Compaction Tamping Machine using Simulink1999Conference paper (Refereed)
    Abstract [en]

    A theoretical model for the dynamic behaviour of a soil compaction tamping machine is derived. The Matlab toolbox Simulink is used to solve the equations of motion. Simulink is used because it is possible to combine the kinetic model of the machine with a more complex FE-model. The theoretical model has been verified experimentally, where the soil compaction tamping machine was run on a simulated soil material. The agreement between the simulation and the experiment is very good, which implies that this simplified model of the machine can be used for a more complete study of the total system, including a more correct soil model.

  • 56. Jönsson, Anders
    et al.
    Broman, Göran
    Östholm, Stefan
    Multidisciplinary Simulation of Active Control of Machine-Tool Vibration in Turning2000Conference paper (Refereed)
    Abstract [en]

    The increasing computer power in modern manufacturing machines has given the possibility to integrate advanced computer based control systems. In this work a simulation model for active control of machine-tool vibration in turning operations is described. The model contains both the mechanical structure and the control system. The simulation is done with and without active control. The structure vibration is suppressed by simulating actuators. The simulation is done to get a first indication of the potentials of a proposed new tool holder design and to test the usability of such multidisciplinary simulations as a supporting tool for product development. The results show that it is possible to simulate the total system. The vibrations of the tool holder tip could be decreased significantly by using reasonable forces. The software used was found to be very user friendly and to be able to perform such coupled simulations in this way during product development must be considered to be a great advantage.

  • 57. Jönsson, Anders
    et al.
    Broman, Göran
    Östholm, Stefan
    Multidisciplinary Simulation of Active Control of Machine-Tool Vibration in Turning2000In: System and Control:Theory and Applications, ISSN 960-8052-11-4, p. 61-64Article in journal (Refereed)
    Abstract [en]

    The increasing computer power in modern manufacturing machines has given the possibility to integrate advanced computer based control systems. In this work a simulation model for active control of machine-tool vibration in turning operations is described. The model contains both the mechanical structure and the control system. The simulation is done with and without active control. The structure vibration is suppressed by simulating actuators. The simulation is done to get a first indication of the potentials of a proposed new tool holder design and to test the usability of such multidisciplinary simulations as a supporting tool for product development. The results show that it is possible to simulate the total system. The vibrations of the tool holder tip could be decreased significantly by using reasonable forces. The software used was found to be very user friendly and to be able to perform such coupled simulations in this way during product development must be considered to be a great advantage.

  • 58. Kao-Walter, Sharon
    A Visit to M.V. Lomonosov Moscow State University (June 2002)2002Other (Other academic)
  • 59. Kao-Walter, Sharon
    Mechanical and Fracture Properties of Thin Al-foil2001Report (Other academic)
    Abstract [en]

    Mechanical and fracture behaviour of thin Aluminium foil (with a thickness of 6-9 mm) was studied. Tensile tests and fracture toughness tests of different material thickness and different specimen size have been performed. Results influence by the size of specimen has been discussed.

  • 60. Kao-Walter, Sharon
    et al.
    Ståhle, Per
    Fracture Behavior of an Ultra Thin Al-foil- Measuring and Modelling of the Fracture Process2001Conference paper (Refereed)
  • 61. Kao-Walter, Sharon
    et al.
    Ståhle, Per
    Hägglund, Rickard
    Fracture toughness of a laminated composite2003In: Fracture of Polymers, Composites and Adhesives II, Elsevier , 2003, p. 355-364Chapter in book (Other academic)
    Abstract [en]

    The fracture toughness of a polymer-metal laminate composite is obtained by mechanical testing of a specimen containing a pre-crack. The result is compared with a calculated fracture toughness based on the measured fracture toughness of the individual layers. The laminate is a material used for packaging. It consists of a thin aluminium foil and a polymer coating. A centred crack panel test geometry is used. Each of the layers forming the laminate is also tested separately. It is observed that the load carrying capacity increases dramatically. At the strain when peak load is reached for the laminate only aluminium is expected to carry any substantial load because of the low stiffness of the LDPE. However, the strength of the laminate is almost twice the strength of the aluminium foil. The reason seems to be that the aluminium forces the polymer to absorb large quantities of energy at small deformation. The result is compared with the accumulated toughness of all involved layers. A more elaborate model is proposed in the light of non-linear material behaviour and development of a fracture process zone at the crack tip. Possible fracture of the interface between the layers is discussed.

  • 62.
    Larsson, Kristofer
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Silverbris, Andreas
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Yngnell, Stefan
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Avfuktning för återanvändning av processluft2001Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Sammanfattning Projektet som genomförts på uppdrag av och i samarbete med företaget ABB-I-R har innefattat att finna och dimensionera en befintlig avfuktningsenhet tillgänglig på marknaden, eventuellt med viss erforderlig anpassning och modifikation. Vidare har uppgiften innefattat att konstruera en applikation till basenhet Cutting-box Original IV. Slutligen ingick även testkörning och intrimning av framtaget lösningskoncept som en del i uppgiften. Principkonstruktion: Första konstruktionsetappen s.k. principkonstruktion inleds med en, enligt Fredy Olssons modell för produktutveckling, framtagen strukturerad uppgiftsutredning och problemställningsanalys. Denna beaktar såväl produktens förhållning till process, omgivning, människa och ekonomi, som sin egen tekniska livscykel uppdelad i etapperna alstring, framställning, avyttring och eliminering. Principkonstruktionen är sedan fortsättningsvis uppdelad i två övergripande problemavgränsningar. En första behandlar själva avfuktningsenhetens principiella verkningssätt, inkluderat anpassningar och modifikationer och en andra behandlar dennas appliceringen i form av placering, montage och röranslutningar till basenhet Cutting-Box. Härefter presenteras en sovrad sammanställning av specifika skall- och börkriterier för de två olika problemavgränsningarna, uppställd utifrån föregående uppgiftsformulering. Denna uppställning utgör underlag för val av produktens principiella verkningssätt, och principiella applikation. Högt värderade och prioriterade kriterier rör såväl tekniska krav på erforderliga kapaciteter för avfuktarkomponenten som erforderliga funktioner hos röranslutningar. Härefter följer en omfattande produktundersökning på idag befintliga lösningar/ produkter. I teorin finns ett större antal metoder för avfuktning av luft som inte berörs i detta arbete och som heller inte är praktiskt relevanta. I praktiken återstår egentligen endast tre tänkbara metoder: kondensavfuktning, adsorbtionsavfuktning resp. absorbtionsavfuktning. En fjärde metod har tagits med som egentligen inte kan klassas som avfuktningsmetod men som ändå är tillämpbar för ändamålet energiåtervinning, nämligen värmeväxling med torrare uteluft. Marknaden för luftavfuktning idag inriktar sig näst intill uteslutande åt adsorbtionsmetoden resp. kondensmetoden. Värmeväxlaraggregat i olika utföranden finns också i omfattande utsträckning. Vid nästkommande moment sker viktning i kriteriematriser av respektive principförslag. Det visar sig ganska tveklöst att kondensprincipen är lämpligast i denna situation. Detta delvis på grund av att kondensprincipen jämfört med övriga avfuktningsprinciper arbetar energisnålt. Den är också jämförelsevis billigare i inköp. Den behöver inte ge en temperaturökning av luften och erfordrar således inget externt kylelement vilket t.ex. adsorbtionsprincipen gör. Den kan hantera höga luftflöden och höga fuktighetshalter vid gällande tryck och temperaturer. Den är inte direkt känslig för sporadiskt inkommande damm eller små smutspartiklar. Metoden bygger på ett enkelt luftflöde där då inget sekundärt luftflöde behöver tillhandahållas utifrån (vilket oftast adsorbtionsmetoden och värmeväxlingsmetoden kräver), detta kriterie har av handledaren på företaget framhållits mycket angeläget . Befintliga energiåtervinningssystem direkt i industriprocesser som bygger på luftavfuktning har ej funnits, varvid själva applikationen framtagits rent idémässigt med hjälp av brainstorm. Vidare visar kriterieviktning att det förhåller sig lämpligast att applicera avfuktningsenheten genom en rördragning som förutom luftflödet genom avfuktaren har utformats med en här kallad ?Bypass Direct Flow? se fig. 10.2 (kapitel 10). Om ett luftflöde över avfuktningsenhetens avsedda maxflöde uppstår, skall en mindre mängd fuktig luft kunna ?smita förbi? i en direktdragning förbi denna och på så sätt ej utsätta avfuktaren för ett för stort påtvingat luftflöde. Då luftflödet istället ligger under avfuktarens avsedda maxflöde kan luftavfuktaren samtidigt suga fuktig luft direkt inifrån Cutting-boxen (detta visas i figur 10.2 med pilar), vilket medför ett kontinuerligt, maximalt utnyttjande av avfuktarens flödeskapacitet. Valda förslag presenteras mer ingående i kapitel 10. Primärkonstruktion: Andra konstruktionsetappen s.k. primärkonstruktion, behandlar först i ett inledningsskede, erforderlig justering och vidareutveckling av utkast från föregående principkonstruktionsetapp. Då det i fortlöpande produktundersökning på detta stadie visat sig att utrymmesbehovet på grund av höga kapacitetskrav och stora anslutningsrör omöjliggör en placering invid basmaskins vänstra kortsida, har en placering på dennas tak valts och kommenterats. Utifrån denna placering framtas rördragningens utformning med anslutningspunkter och exakta mått (se fig. 12.4). Komplett underlag för ett principiellt produktutkast möjliggör härefter en utformning av detta. Produktutkastet består av utvecklad principskiss (se fig. 13.2) följd av klassificeringslista vilken anger art och behandlingstyp på produktens alla ingående delar och enheter. Följande kapitel rör val av komponenter. För luftavfuktare som specialbehandlad färdig komponent bestäms företag ARIDUS som leverantör. Företaget är svenskt, har hög kundanpassning och erfarenh et av industriella tillämpningar. Modell för avfuktare väljs till Lak-120 alternativt Lak-250, beroende på var man vill lägga sig kapacitets och prismässigt. Viss erforderlig anpassning och modifikation av Aridus standard avfuktare görs också i samband med komponentvalet. Dessa rör främst problemet med trappvis temperaturstegring i det slutna systemet. För att undvika detta har ett av de i luftavfuktaren ingående återvärmande elementen flyttats ur denna och bidrar istället till uppvärmning av lokalen. Rördragningskomponenter (se fig. 14.19), delvis rutinmässigt behandlade, är valda ur företag Lindabs produktsortiment från produktserie Safe. Dessa presenteras i en komponentspecifikation. Detaljkonstruktionsarbete görs eftersom luftavfuktarens fötter ersatts med ett specialkonstruerat stativ (se bilaga 7 resp. 11 ) för förbättrat fastmontage och gynnsam belastning förlagd till basmaskinens bärande balkar. En slutlig sammanställning med ritningar och specifikationer på produkten är härefter uppställd. Slutligen ges förslag på vidare utveckling, rekomendationer vid testkörning och alternativa lösmningsförslag på möjliga uppkommande problem som kontinuerlig temperatur förändring eller kontinuerlit fuktstegring i det slutna systemet.

  • 63.
    Liljekvist, Andreas
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Larsson, Johan
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Sjöholm, Anders
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Moduluppbyggd reglagelåda med ergonomiskt utformad körspak2002Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Det här examensarbetet har genomförts i samarbete med Metso Dynapac AB i Karlskrona. På deras asfaltsvältar finns idag olika modeller av körspakar. De har samma grundfunktion och bör kunna samordnas till ett gemensamt reglage. Detta ger möjligheter att använda rationell tillverkningsmetod p.g.a. volymen. Ergonomi är ett konkurrensmedel, där placering och utformning är viktigt.

  • 64.
    Lindblad, Johan
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Newin, Anders
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Olsson, Per
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Upphängningssystem2002Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Examensarbetet som utförts på Institutionen för Maskinteknik vid Blekinge Tekniska Högskola i samarbete med Kockums AB har benämningen ? Upphängningssystem?. Dagens upphängning av rör, ventilationsrör och kabelbanor består av ett antal olika singelupphängningar utan större samordning. Detta har gjort att Kockums AB önskat få fram ett samordnat upphängningssystem som klarar av alla dessa upphängningstyper. Utifrån denna problemställning har vi arbetat oss fram till ett upphängningssystem bestående av ett multisystem och ett flertal singelupphängningar för rör, kabelbanor och ventilation. Multisystemet är ett skensystem som tillåter kombinerad upphängning av rör, kabelbanor och ventilationsrör. Vid utförandet av examensarbetet har vi använt oss av professor Fredy Olssons metoder för integrerad produktutveckling. Fredy Olssons metod är indelad i två faser, principkonstruktion och primärkonstruktion. I principkonstruktionen tog vi fram sjutton olika principförslag som utvärderades mot de ställda kriterierna. Av denna utvärderingen gick nio konstruktioner vidare. Dessa produktförslag valde vi sedan att vidareutveckla varvid vi gjorde en slutlig utvärdering. I primärkonstruktionen har sex olika förslag, vilka arbetats fram under principkonstruktionen, bearbetats till färdiga produkter i form av beräkningar, komponentval och materialval.

  • 65.
    Myrén, Marcus
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Olsson, Jörgen
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Modal Analysis of Exhaust System1999Other (Other academic)
    Abstract [en]

    A modal analysis is performed on an exhaust system for cars. Natural frequencies and mode shapes are correlated between experimental and finite element models. MAC-values are calculated. Theories and guidelines for modal analyses of exhaust systems are discussed.

  • 66.
    Mårtensson, Anders
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Rietz, Henrik
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    System med "Pop-up"-munstycken för helikopterplattform på korvett.2001Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Denna slutrapport är resultatet av ett samarbete mellan Kockums AB / Karlskronavarvet och Blekinge Tekniska Högskola (Institutionen för maskinteknik). Det av Kockums initierade projektet har benämnts till ?System med ?Pop-up?-munstycken för helikopterplattform på korvett?. Uppdraget har bestått i att utprova och verifiera ett befintligt munstycke, vars primära funktion är släckning av petroliumbränder (helikopterolycka) på ett stelthfartygs helikopterplattform. Munstyckets sekundära funktion består i att vattenbegjuta (sk. wash-down) stelthfartyget, för att minska dess IR-signatur och för användning vid NBC-sanering (Nuclear, Biological and Chemical). Munstyckena skall vara dolda i fartygsskrovet av två anledningar. Dels för att helikoptrar skall kunna landa säkrare på plattformen och dels för att det aktuella fartyget är av sk. stealth-typ vilket innebär att så många funktioner som möjligt skall byggas in och döljas i fartyget skrov. Kockums anser att befintligt munstycke är otillräckligt verifierat, tungt och dyrt. Med denna bakgrund har målsättningen med projektet varit att, med erhållna provresultat som grund, utveckla ett munstycke som uppfyller samtliga ställda kund-/myndighetskrav och önskemål. Det utvecklade munstycket skall presenteras som en virtuell modell för att påvisa dess uppbyggnad, verkningssätt och placering för optimal funktion. Sammanställning av de på produkten ställda skall- och börkriterierna visade att det befintliga munstycket inte uppfyllde flera av dessa kriterier. Främst består bristen av att munstycket inte uppfyller kravet på, vid helikopter-brand, skall täcka helikopterns fulla höjd med brandsläckningsvätska. Brandsläckningssystemet är idag inte kapacitetsmässigt dimensionerat för, inom kort, kommande regelverk inom detta område. Detta innebär att tidigare utförda beräkningar (kapacitet, placering mm) bör betraktas som ogiltiga och att då också det befintliga munstyckets kapacitet och funktion bör ifrågasättas pga förändrade tryck och flöden i brandsystemet. Resursbrist på Kockums AB har inneburit att verifierande prover av det befintligt munstyckets funktion och spridningskapacitet inte har kunnat utföras. Detta faktum har resulterat i att utvecklingsarbetet delvis har fått baserats på resultat ifrån utförd marknadsundersökning. Ett norskt företag, vid namn Pop Spray Fire Fighting System AS (PSFS), har utvecklat ett munstycke (PSFS-HV7) avsett för brandbekämpning på både land- respektive havsbaserade (tex fartyg och oljeriggar) helikopterdäck. Då provdata funnits tillgängligt för detta munstycke har huvuddimensioner (som påverkar munstyckets flödesbild) ifrån detta munstycke använts för konstruktion av wash-down respektive brand-släckningsmunstycke. I utvecklingsarbetet av munstyckena har särskild vikt lagts på material-undersökning, minimering av antalet ingående komponenter och maximering av antalet gemensamma komponeter för de båda munstyckena. Utvecklingsarbetet med modifierad dyse I och II har, jämfört med befintligt munstycke, resulterat i viktbesparingar tillsammans med ett lägre pris per enhet. Det kommer dessutom att innebära förenklad lagerhållning, installation och förenklat service /underhåll. Verifiering av kapacitet och funktionstester har ej kunnat utföras på de utvecklade munstyckena. Trots detta bedömer vi att munstyckena väl kommer att uppfylla ställda kriterier då huvuddimensioner ifrån det norska munstycket använts i konstruktionen. De på munstyckena ställda skall-/ börkriterier som har kunnat utvärderas påvisar en hög uppfyllandegrad.

  • 67. Nordebo, Sven
    et al.
    Mohammed, Abbas
    Lundbäck, Jonas
    On the Capacity of Polarization Diversity in Satellite Communications2002Conference paper (Refereed)
  • 68.
    Olofsson, Marcus
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Persson, Alexander
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Persson, Johan
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Persson, Joakim
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Fällbar ROPS med tak/FOPS2001Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This examination project is produced in co-operation with Svedala Compaction Equipment AB. The main goal for the project was to reduce the height of the ROPS on the CC 422 asphalt-roller. The reduced height provides a more free choice of roads for transportation of the asphalt-roller. So far have bridges, viaducts and other obstacles affected on the choice of roads. With guidelines from Svedala Compaction Equipment AB and Fredy Olsson?s model of concurrent engineering criteria were defined. These criteria were used in the grading of the different principal solutions. An evaluation resulted in a reduction of solutions from ten to two. These two solutions were to be more developed in the next face in the project ? the primary face. The primary face started with a further development of the solutions. This was followed by a decision were ?Sänkning rakt ned? was chosen for further development. The adjustment of the height is performed by hydraulics. The height-lock is performed by cotters. The new design of the ROPS provides a possibility of reducing the transport-height with 500 mm. The new ROPS will roughly estimated cost about 18 000 SEK.

  • 69. Olsson, Ulrika
    et al.
    Haller, Kristian
    Östholm, Stefan
    Dynamic Automated Measurement on Light Weight Test Panels1999Conference paper (Refereed)
    Abstract [en]

    This paper describes an automated approach to modal testing utilizing a robot control to position a Laser Doppler Vibrometer (LDV) beam. The LDV measures the velocity response of test panels to a broad band force excitation. The implementation of the laser beam approach involves moving the beam once for each member of the velocity-force set. It is critical that the beam is positioned precisely, and the measurement set is correctly correlated to the specimen geometry. A programmed robotic system was used for the laser positioning and for keeping the measurement set correctly identified with respect to the specimen geometry. The result clearly shows the possibility to automate time consuming modal measurement of lightweight structures by utilizing a robot to control a LDV.

  • 70.
    Outhier, Maxime
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Rydström, Vilhelm
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Sanz, Imanol
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    TRANSFERRING OF MOVEMENT FOR STEERING EQUIPMENT2001Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This Examination Thesis was done at the Blekinge Institute of Technology of Karlskrona. The work is a part of the education to Bachelor of Science in product development. The task consists of changing the steering wheel transmission of the DYNAPAC CA soil compactor machine made by Svedala Compaction Equipment AB. During the work we have followed the Fredy Olsson product development method. The work is divided in two parts: The Concept phase and The Primary Construction phase. In the Concept phase we first defined the project. After that we did investigations to find different solutions, which were electronic solution, hydraulic solution, gears and shafts, synchronous belts, single wire and double wires. Then, we made descriptions of all the proposals, next step was a primary evaluation of the product solutions. We used three matrixes to find out which solutions we were going to keep for the progress of the project and found the synchronous belt as the most advantageous steering system. In the Primary Construction we chose the most suitable belt using a criterions matrix. We designed the modifications of the different parts of the steering system with the I-DEAS CAD system. We also made some tests,calculations and cost analyses. Our final proposal is a new steering system, which is based on the mentioned synchronous belts and pulleys. We think that the found solution is going to work safe and successfully for a very long time. It is also harmless for the nature and the environment.

  • 71.
    Pettersson, Daniel
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Lejdeby, Mikael
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Zarate, Inigo Oz. de
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Delamarliere, Mathieu
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Bitumen Applicator2002Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This bachelor degree thesis was assigned to us in the fall semester of 2001. The purpose was to redesign a machine for the company Asea Brown Boveri (ABB) in Karlskrona. ABB HVC in Karlskrona is manufacturing high voltage cables. Amongst these the seacables are the largest and most complex. The seacables are heavy naval cables and lies on the bottom of the sea. For these heavy-duty applications the cables need good armouring. The armouring, which is made of steel, needs a corrosion protection layer that is very wear resistant. For this ABB uses industrial bitumen, a form of asphalt. The cables run through a whole production line where the bitumen is applied on the cables at a temperature of 160°C. In this working station the cable armouring wires are winded on the cable and the bitumen is applied. The present machine is old and needs replacement. In fact the whole AR 50 line is in plan for restoration. This project is to redesign the bitumen application machine and eliminate the present problems. The machine still works, but not satisfying. It is a hazardous workplace when the bitumen is a very dirtying media that sticks to almost everything and it is very hard to clean. It is also very hot and a splash could burn a person. There is also a problem with slag products from the armouring in the surplus bitumen. The main work has been concentrated on eliminating the larger problems and develop a well working machine that is easy to run and maintain. By applying Fredy Olssons method for product development the work has proceeded step by step. The work started with finding different concept solutions. To simplify the work the machine was divided in four parts, the container for storage and heating, the nozzle for transporting and spreading the bitumen on the cable, the reservoir for collection of the surplus bitumen and to separate the slag particles and the table to hold the distribution rings and the adjustment screw, this to get a better view of all parts and components. These ideas from this phase where evaluated with main focus on the criterions. For al the four units one solution was filtered out for further development. In the primary construction phase the concepts where transformed in to a whole machine. This phase contains research of components and detail construction of unique parts. Small adjustments of the concepts from the first stage had to be made to create the best solutions. The machine process can be described shortly. From a main tank outside the building the bitumen is transported to the container where it is reheated to 160°C. From this container the liquid is pumped up through a heated pipe and by a nozzle spread over the cable. On the cable two rings spread the bitumen as a smooth layer on the cable. The surplus bitumen will fall down in to the reservoir where the slag particles are separated. From here the surplus will run back to the container for recycling. To be added the first of the two rings also collects the incoming armouring wires and by the rotation of the cable they are winded around it. This leads to large loads on the construction when the cable traction force is 12 tons.

  • 72.
    Robertsson, Martin
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Skoglund, Örjan
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Möjligheter till reduktion av ljud från kuggväxel i markvibrator2003Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Bakgrunden till projektet är ett examensarbete initierat av Metso Dynapac. Företaget tillverkar maskiner för utläggning och packning av beläggnings- och fyllnadsmaterial, t.ex. vid asfaltering. En av de maskiner som företaget tillverkar är en markvibrator, vilken har problem med buller. En ingående komponent i maskinen består av en kuggväxel. Kuggväxeln bedöms av företaget vara en av källorna till buller, vilket fastställts genom mätningar. Pga. nya EU-direktiv krävs en sänkning av maskinens ljudnivå. I examensarbetet ingår därför att undersöka och föreslå lämpliga åtgärder i syfte att reducera ljudnivån från kuggväxeln. Rapporten inleds med en litteraturstudie inom området kugghjulsbuller vilken har till uppgift att undersöka, värdera och dokumentera faktorer som påverkar ljudnivån i kuggväxeln. I det kapitel som följer presenteras de krav som ställs på kuggväxeln. Kraven har utarbetats i samråd med företaget och skall uppfyllas då omkonstruktion av kuggväxeln sker. Befintlig kuggväxel undersöks sedan gällande geometri och hållfasthet både analytiskt och numeriskt. Även svagheter i konstruktionen har studerats och dokumenterats. Då dimensionering av nya kugghjul sker gäller de befintliga kugghjulen som referens, dvs. hållfasthetsmässigt skall de framtagna hjulen vara likvärdiga eller bättre. Dessutom skall konstruktion ske under samtidig bullerreduktion. För dimensionering av kuggväxeln har programvaran KISSsoft Hirnware tagits till hjälp. Programmet klarar de flesta förekommande maskinelement och har egenhändigt införskaffats av examensarbetarna. Ofta är det önskvärt att optimera konstruktionen, t.ex. genom att reducera massan. I detta fall var parametern som skulle studeras istället buller och att denna möjlighet gavs togs därför i grundligt övervägande vid valet av mjukvara. Ett stort antal lösningsförslag har tagits fram mha. programmet, där de kravuppfyllande och ur bullersynpunkt betraktade bästa lösningarna valts. De lösningar som utsetts är ett set kugghjul med rakskurna kuggar och ett set med snedskurna kuggar. De två tänkbara lösningarna har resulterat i ytterligare modifieringar av i kuggväxeln ingående komponenter. Förslagen har därför genomarbetats för att kunna presenteras som helhetslösningar. Vidareutvecklingen har inneburit beräkningar avseende lager, samt modifiering av de ingående delarna; drivande axel, hylsa, distans och excenterhus. Även gällande toleranser har till viss del undersökts. De två tänkbara lösningarna har utvärderats och kravuppfyllelsen kontrollerats, varefter rekommendation gjorts av den möjliga lösning som bedöms inneha störst förbättringspotential. Avslutningsvis presenteras rekommenderat förslag innehållande ritningsunderlag färdigt för tillverkning, samt bestämda produktionstoleranser. Kvarstår i arbetet gör för företagets del prototypframtagning och utprovning av produkten, vilket sker i form av nya bullermätningar på maskinen.

  • 73. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Nonlinear Dynamics of Grains in a Liquid-Saturated Soil2003In: Nonlinear dynamics, ISSN 0924-090X, E-ISSN 1573-269X, Vol. 35, no 2, p. 187-200Article in journal (Refereed)
    Abstract [en]

    A new kind of nonlinearity of inertial type caused by accelerated motion of interacting particles is described. The model deals with an ensemble of grains immersed into a vibrating fluid. First, the nonlinear vibration of two connected grains is studied. The temporal behaviours of displacement and velocity, as well as spectrum of vibration, are analysed. Numerical simulations are performed. Then an infinite chain of grains is considered and the corresponding differential-difference equation is derived. For the continuum limit the inhomogeneous nonlinear wave equation is solved and temporal profiles are calculated. A new resonant phenomenon is described and the resonant curves are constructed.

  • 74. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Enflo, Bengt
    Nonlinear standing waves in a layer excited by periodic motion of its boundary2001In: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 47, no 4, p. 452-460Article in journal (Refereed)
    Abstract [en]

    A new analytical approach is developed for the description of standing waves caused by arbitrary periodic vibration of a boundary. The approach is based on the nonlinear evolution equation written for an auxiliary function. This equation offers the possibility to study not only the steady-state acoustic field, but also its evolution in time. One can take into account the dissipative properties of the medium and the difference between one of the resonant frequencies and the fundamental frequency of the driving motion of the wall. An exact non-steady-state solution is derived corresponding to the sawtooth-like periodic vibration of the boundary. The maximal amplitude? values of the particle velocity and the energy of standing waves are calculated. The temporal profiles of standing waves at different points of the layer are presented. A new possibility of pumping a high acoustic energy into a resonator is indicated for the case of a special type of wall motion having the form of an ?inverse saw?. Theoretically, such a vibration leads to an ? explosive instability? and an unlimited growth of the standing wave. For a harmonic excitation, the exact non-steady-state solution is derived as well. The standing wave profiles are described by Mathieu functions, and the energy characteristics by their eigen-values.

  • 75. Rudenko, Oleg
    et al.
    Sobisevich, A.L.
    Sobisevich, L.E.
    Hedberg, Claes
    Enhancements of energy and Q-factor of a nonlinear resonator with increase in its losses2002In: Doklady Akademii Nauk, ISSN 0869-5652, Vol. 383, no 1, p. 330-333Article in journal (Refereed)
    Abstract [en]

    A phenomenon that is paradoxical at first sight is studied: an appropriately-organized energy outflow from a resonator cavity results not in the attenuation of nonlinear vibrations but in their noticeable enhancement. An increase in the resonator Q-factor and in the energy accumulated in it is well pronounced when the frequencies of the higher harmonics generated in a nonlinear medium are close to the natural frequencies of the resonator. An important example of a nonlinear system with the necessary properties is an acoustic resonator with selective losses.

  • 76. Rudenko, Oleg
    et al.
    Sobisevich, L.E.
    Sobisevich, A.L.
    Hedberg, Claes
    Nonlinear response of a layer to pulse action in diagnostics of small inhomogenities2000In: Doclady, Section Mechanics (Reports of the Russian Academy of Sciences) / Doklady Akademii Nauk, ISSN 0869-5652 , Vol. 374 ; 1-3, p. 194-197Article in journal (Refereed)
    Abstract [en]

    Giant nonlinear respons are observed at acoustic irradiation of microscopic gas bubbles in liquids, cracks and fluid-filled pores in solids; and compressed contact of rough surfaces, and is used in diagnostics of materials of industrial and geological structures. Reconstruction of characteristics of a scattering inhomogeneity requires an analyses of complicated inverse problems. The problem of plane-wave incidence upon a layer is simple and serves a model for more complicated inhomogeneities; its response enables us to reconstruct the spectral composition and field structure of other nonlinear scatterers.

  • 77.
    Sandberg, Magnus
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Währborg, Fredrik
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Dynamic Analysis of Handle Attachment for Brush Saws1999Other (Other academic)
    Abstract [en]

    The user of a brush saw is exposed to vibrations in hands and arms. Theoretical and experimental modal analysis is used to investigate the handle attachment. The theoretical models are simplified to decrease the time for solving them. The methods and models of this work will later be used in the design process to decrease vibrations.

  • 78.
    Tykesson, Annika
    et al.
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Dogertz, Julia
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    Lundin, Maria
    Blekinge Institute of Technology, Department of Mechanical Engineering.
    NBC-anläggning2003Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Projektet bestod i att utveckla en anläggning för personsanering av biologiska-, kemiska- och nukleära stridsmedel, en så kallad NBCanläggning. Arbetet har initierats av Marinens Sjösäkerhetsskola i Karlskrona. Under arbetets gång har Fredy Olssons produktutvecklingsmodell tillämpats. Projektets tyngdpunkt har legat i att söka komponentalternativ för de önskade ändamålen och för att uppfylla kraven. Anläggningen är långt ifrån produktionsklar, men ett omfattande grundarbete har gjorts inför ytterligare bearbetning och komplettering med beräkningar samt vissa komponentval.

  • 79. Wall, Johan
    Dynamics Study of an Automobile Exhaust System2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Low vibration levels are a critical objective in automobile exhaust system design. It is therefore important for design engineers to be able to predict, describe and assess the dynamics of various system design proposals during product development. The aim of this thesis is to provide a deeper understanding of the dynamics of automobile exhaust systems to form a basis for improved design and the development of a computationally inexpensive theoretical system model. Modelling, simulation and experimental investigation of a typical exhaust system are performed to gain such an understanding and to evaluate modelling ideas. Special attention is given to the influence of the bellows-type flexible joint on the dynamics of the exhaust system. The investigations show that the exhaust system is essentially linear downstream of the flexible joint. Highly simplified finite element models of the major components within this part are suggested. These models incorporate adjustable flexibility in their connection to the exhaust pipes and a procedure is developed for automatic updating of these parameters to obtain better correlation with experimental results. The agreement between the simulation results of the updated models and the experimental results is very good, which confirms the usability of these models. Furthermore, the investigations show the great reduction of vibration transmission to the exhaust system that the bellows-type joint, either with or without an inside liner, gives in comparison with a stiff joint. For the combined bellows and liner joint, vibration transmission is, however, higher than for the bellows alone. Inclusion of the liner also makes the exhaust system behaviour significantly non-linear and complex, whereas the system behaviour proves to be essentially linear when the joint has no liner. This shows the importance of including a model of the liner in the theoretical system model when the liner is present in the real system. The choice of whether or not to include a liner in the real system is obviously a complex issue. The advantages of reduced bellows temperature and improved flow conditions should be weighed against the disadvantages found in this work. By combining the above findings it is concluded that in coming studies of how engine vibrations affect the exhaust system, the latter may be considered as a linear system if the flexible joint consists of a bellows. If the joint also includes a liner, the system may be considered as a linear subsystem that is excited via a non-linear joint.

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