This report presents a thesis done at Husqvarna Groups component department. The purpose was to redesign an electrical test rig for a Husqvarna chainsaws so that it was robust enough to withstand tests for at least 50 hours at a speed of 14 000 rpm. The electrical test rig is driven by an electric motor that sets the rotating system in motion. The current test rig is designed to demonstrate that the relevant load conditions are achieved and the next step is to redesign the test rig so that it is robust enough to cope with component testing. So far, the tests has lasted for at most 1 minute and the coupling has been creating problems for the system since it opens up during tests because of the centrifugal forces. The choice of coupling is therefore to be reviewed. In previous tests the test rig was noted to vibrate more than expected during acceleration up to 14 000 rpm. The test rig is currently rigidly fixed onto a steel table during tests and this reduce the recreation of the chainsaw natural movement. The thesis therefore includes a review of the possibility of a vibration damping system. Background for the choice of the coupling and vibration damping system was based on a study containing analysis of current test rig and a previous thesis done on the test rig before its development. Theories and data collection was done through literature study of relevant articles about power of transmission and vibration. Interviews was carried through with knowledgeable persons from Husqvarna with experience of test rigs. The study then continued with the development of relevant calculations and by a concept study with creation of construction criteria lists. The concept study was finished off with a Pugh’s matrix with a comparison of the concepts.   The result from the concept study for the coupling which was recommended was a coupling called flex shaft. This consists of a hard twisted spring and is beneficial for designs that require nonlinear transmission, are capable of tests at high speed and can transfer the desired torque. Flex shafts are specially ordered based on special criteria’s, making it suitable for structures with multiple and complex requirements. The vibration damping system recommended from calculations and the concept study consisted of four vibration damping elements of rubber. These should be attached under the aluminum plate that the test rig is fixated on. Each vibration damping element need to have a max stiffness of 20.55 N/mm and to be able to bear a weight of 6.55 kg. If the recommendations are followed to create a robust test rig with the flexible shaft coupling and the proposed vibration damping system testing of components and analyzes will be more easily implemented at Husqvarna. This will also help the research and development forward in both a cost and time effective manner. / Denna rapport presenterar ett examensarbete utfört på Husqvarna Groups komponentavdelning.  Syftet var att omkonstruera en elektrisk testrigg för en Husqvarnas motorsågar så att den blev tillräckligt robust för att klara av körningar i minst 50 timmar med ett varvtal på 14 000 rpm. Den elektriska testriggen drivs av en elmotor som sätter det roterande systemet i en motorsåg i rörelse. Nuvarande testrigg är framtagen för att påvisa att relevanta lastfall uppnås och nästa steg är att omkonstruera testriggen så att den blir robust nog för att klara komponentprovning. Hittills har tester i max 1 minut genomförts och den koppling som används skapar problem för systemet då klokopplingen öppnar sig vid körning på grund av centrifugallasterna. Valet av koppling önskades därför att ses över. Vid tidigare körningar märktes även att testriggen vibrerade mer än väntat vid accelerationen upp till 14 000 rpm. I nuläget är testriggen stumt fastmonterad i ett stålbord vid körningar och dessa begräsningar tros försämra återskapandet av motorsågens naturliga rörelsemönster. Examensarbetet innefattar därför även att se över möjligheten för ett avvibreringssystem och hur detta skulle kunna utformas. Bakgrund inför valet av koppling och avvibreringssystem baserades på en förstudie innehållande analys av nuvarande testrigg och ett tidigare examensarbete som utförts på testriggen innan dess uppkomst. Teorier och datainsamling gjordes genom litteraturstudie där relevanta artiklar om kraftöverföring och vibrationer studerades samt att intervjuer med insatta personer från Husqvarna med erfarenhet av testriggar genomfördes. Studien fortsatte sedan med framtagning av relevanta beräkningar och genom en konceptstudie där konstruktionskriterielistor skapades och koncepten sedan jämfördes genom Pugh’s matris. Resultatet som framkom från konceptstudien för koppling och rekommenderades var en koppling kallad flexaxel. Denna består av en hårt tvinnad fjäder och är fördelaktig vid konstruktioner som har ickelinjär kraftöverföring. Flexaxeln klarar även av körningar på höga varvtal samt att föra över det önskade vridmomentet. Denna typ av koppling specialbeställs utefter ställda kriterier, vilket gör den lämplig för konstruktioner som ställer flera och komplexa krav. Avvibreringsystemet som rekommenderades framkom från beräkningar samt konceptstudie och bestod av fyra stycken avvibreringselemnet i gummi. Dessa ska fästas under den aluminiumplatta testriggen är fastmonterad på och vardera avvibreringselement behöver ha en maxstyvhetet på 20,55 N/mm samt kunna bära en vikt på minst 6,55 kg. Om rekommendationerna följs för att skapa en robust testrigg med flexaxeln som koppling och det föreslagna avvibreringssystemet kommer tester av komponenter och analyser lättare kunna genomföras på Husqvarna. Detta kommer även kunna effektivisera forskningsarbete och utvecklingsprocesser framåt på ett både kostnads- och tidsmässigt sätt.

Abstract Progressive collapse implies that a local damage on a building leads to a continuing collapse. This can include the whole or a part of the building. It was first in 1968, after a gas explosion in a 22 story building, Ronan Point, London that led to a progressive collapse that made the world aware of this problem and that it needed to be addressed. The event made that certain standards was implemented in several countries to decrease the risk of progressive collapse. The standards for progressive collapse arrived in Sweden 1972. In Sweden there is two standards that concerns dimensioning about progressive collapse, which are 1991-1-7 and 1992-1-1. Although the standards are hard to interpret and design engineers have had to draw their own conclusions. This paper does only focus on rules about vertical and horizontal joints. In the paper the difficulty that comes with dimensioning the different standards are interpreted and made clear. The interpretations that have been made in this paper is suggestions and to show how well the theory is matched to the practice, to showcase this I’ve made some prefabricated cases. The most important conclusions of this paper is: The actors need to have more knowledge about progressive collapse It’s a clear that we need a standardized method, because practitioners are doing it in many different ways Today’s standards need to be supplemented from different areas, which is shown in chapter 5.1.1 There is also further studies needed in this area, progressive collapse Keywords: Progressive collapse, Vertical joints, Horizontal joints, Accidental action

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The aim of this study was to map the school library research field for the last 20 years.The research questions asked were:1. Which researchers and publications can be identified in the research base of school library research in the time period 1995-2014, and what relations can be identified between them?2. Which researchers and publications can be identified in the research front of school library research in the time period 1995-2014, and what relations can be identified between them?3. Which terms can be identified in school library research in the time period 1995-2014?To answer these questions, a bibliometric study of the research field was done through publications retrieved from the database Web of Science. The metadata of the documents were analyzed in VOSviewer, a software program used to find relations between publications, researchers and subject terms. The research methods used were co-citation analysis, bibliographic coupling and co-word analysis.The results indicate that Lance and Kuhlthau dominate the research base with their publications about information literacy, information searching and school library impact studies. The research front is focused on use of electronic resources, digital media and information literacy. Clyde and Montiell-Overall are the main researchers.

This thesis is about folding an ergonomic stall fork shaft in the middle. Reason for the folding of the shaft is partly a customer wish but the main reason is the high cost of shipping. The cost of shipping will be relatively low if the package size is kept below the size of which the shipping company recommends. If you want to transport a package that is larger than the recommend size, the shipping cost well rise drastically.In this case, the cost of a package with size of one meter is deemed to be a profitable shipping cost. The problem is that the total length of the entire stall fork is 1.5 meters, which increases the shipping cost by about 100 SEK per package. Therefore, the stall fork must be folded in the middle to become cheaper to ship.The task is to get on a good and inexpensive solution to a clutch mechanism that allows customers to very easily and simply connect the two shafts together. Because of the shaft being ergonomic, it reduces physical abrasion damages and therefore is the main selling argument. That’s why it is very important not to bring any changes to the ergonomic design or, in worst case, as little as possible.The result was a coupling out of a polymer material that divides the shaft approximately from the middle, has a low weight and is easy for the consumer to assemble the two parts of the shaft. The work was carried out by studies of different couplings to be able to come up with a number of different proposals for splitting of the shaft. Furthermore were different materials closely examined and manufacturing methods that the coupling can be manufactured by.The result was a prototype of coupling out of a polymeric material that divides the shaft approximately in the middle, has a low weight and is easy for the consumer to assemble the two shaft halves. The coupling consists of parts, male, female and a core in the middle to make the link robust.

<p>Syftet med detta arbete var att undersöka metoder för modellering och realtidssimulering av fordonskomponenterna koppling och däck. Avsikten skulle sedan vara att implementera utvalda modeller i simulink för användning tillsammans med en befintlig fordonssimulator. Arbetet innehåller en litteraturstudie som ger fysikalisk förståelse för fordonskomponenterna samt vägledning vid valet av modelleringsmetod.</p><p>Utmaningen med kopplingen var att modellera övergången mellan låst och</p><p>slirande tillstånd. Efter utvärdering av olika metoder valdes en metod som använder samma systemstruktur för båda fallen, dvs ett system med två frihetsgrader.</p><p>Däcksmodellen valdes med hänsynen att ett trovärdigt beteende skulle uppnås utan att kräva för mycket beräkningskraft. En metod byggd på fysikaliska resonemang är svår att få verklighetstrogen med begränsad komplexitet. Valet föll därför på metoden Magic Formula som är en metod baserad på experimentella mätningar som är vanligt använd i realtidstillämpningar.</p><p>Ett problem vid modelleringen av både koppling och däck är sista steget i simuleringen innan kopplingen låser sig respektive däcket går från slirande till rullande. Orsaken är att simuleringen görs diskret med fix steglängd och en hög sannolikhet för att övergången mellan tillstånden "missas" och en oscillering uppstår. Problemet löses med hjälp av en prediktering av nästkommande beräkningssteg.</p><p>Med modellerna implementerade och sammankopplade med den övriga fordonsmodellen erhålls en acceptabel körkänsla vid realtidssimulering på en helt vanlig hemdator. Med detta anses syftet med detta arbete vara uppfyllt.</p>

By combining traditional Internal Combustion Engine technology with electric motors, Koenigsegg Automotive AB can benefit from certain advantages that arise from this type of configuration, benefits that can then be implemented in their super sportscar, Regera. Example of an advantage is that the internal combustion engine can be scaled down, which gives a significant weight saving, but no further compromise on the overall effect as a result. Another example is that the electric motor's character of "direct power transmission" is used in a rapid acceleration where a conventional petrol engine has a certain delay. The purpose of the degree project has been to develop a concept for a torque-transmitting joint/coupling. The project is based on the fact that today's connection between the different motors tend to tune in on each other's natural frequencies, which under certain conditions leads to an amplitude increase in vibrations. This in turn gives off noise and in the long run this can lead to the joints becoming exhausted and eventually break down. Nevertheless, the company must also have the possibility to use the concept at other points where today they also use boom connections in the car. The work in this degree project has been limited to dealing only with the concept development process of the joint/coupling. The goal of the project is that the finished concept will satisfy all requirements determined by the product specification, this will be realized by a concept development process, CAD modeling and a simpler design analysis of the concept prototype. Based on the literature study, the main causes of the problem were identified. To find a suitable concept, five proposals were made for the design of the joint/coupling. The selected concepts were generated with inspiration from the frame of reference and the generation process, the concepts are illustrated in the report using models in CATIA V5. The result of the thesis was two theoretical concepts on a torque-transmitting joint between a shaft and a hub. The concepts AH1 and AH2 principles are intended to be incorporated in the car model and give rise to a functional improvement with less noise, a longer service life, better strength / weight ratio but at the same time be easy to assemble / disassemble in the car without having to make too extensive modifications. The goal of the concept development is for the concept to meet all requirements determined by the final product specification. / Genom att kombinera traditionell förbränningsmotorteknik med elmotorer kan Koenigsegg Automotive AB dra nytta av vissa fördelar som uppkommer med den här typen av konfiguration, fördelar som sedan kan implementeras i deras supersportbil, Regera. Exempel på en fördel är att förbränningsmotorn kan skalas ner, vilket ger en betydande viktbesparing, men ingen vidare kompromiss på den totala effekten som resultat. Ett annat exempel är att elmotorns karaktär av ”direkt kraftöverföring” kan nyttjas vid en häftig acceleration där en konventionell bensinmotor har en viss fördröjning. Syftet med det här examensarbetet har varit att utveckla ett koncept för ett vridmomentsöverförande förband/koppling. Projektet grundar sig i att dagens förband mellan de olika motorerna tenderar att stämma in på varandras egenfrekvenser, vilket under vissa förhållanden leder till en amplitudökning av vibrationer. Detta ger i sin tur ifrån sig missljud och i förlängningen kan detta leda till att förband utmattas och så småningom leda till brott. Likväl ska företaget även ha möjligheten till att använda konceptet på andra punkter där de idag också använder sig utav bomförband i bilen. Arbetet i detta examensarbete har avgränsats till att enbart behandla konceptutvecklingsprocessen av förbandet/kopplingen. Målet med projektet är att det färdiga konceptet skall tillfredsställa samtliga krav bestämda av produktspecifikationen, detta ska realiseras av en konceptutvecklingsprocess, CAD-modellering och en simplare konstruktionsanalys av konceptprototypen. Utifrån litteraturstudien identifierades de främsta orsakerna till problemet. För att finna ett lämpligt koncept framställdes fem förslag på utformningen av förbandet/kopplingen. De utvalda koncepten genererades med inspiration från referensramen och genereringsprocessen, koncepten illustreras i rapporten med hjälp av modeller i CATIA V5. Resultatet av examensarbetet blev två teoretiska koncept på ett vridmomentsöverförande förband mellan en axel och ett nav. Koncepten AH1 och AH2 principer är tänkt att inkorporeras i bilmodellen och ge upphov till en funktionsförbättring med mindre buller, en längre livslängd, bättre förhållande mellan styrka/vikt men samtidigt vara lätt att montera/demontera i bilen utan att behöva göra allt för omfattande modifikationer. Målet med konceptutvecklingen är att konceptet skall bemöta samtliga krav bestämda av den slutgiltiga produktspecifikationen.

Crosstalk is defined as an unwanted coupling between the conductors. By this it is meant that signals from one of the signal conductors (a generator in this case) are coupled to another signal conductor (receptor), or conductors (receptors), depending on the number of conductors in the vicinity of the generator. Crosstalk in this way affects the signal level on the receptor and thereby affects the total system performance within the system. This can happen in several ways, one of which is through edge coupling. Edge coupling is a process where two signal conductors are placed beside each other in the same layer while the ground conductor could have been placed either under these conductors, in a separate layer like Mclin (Microstrip coupled lines) and Sclin (Coupled striplines), or beside the signal conductors as in Cpwcpl2 (Coplanar wave guide coupled lines). This then means that edge coupling occurs through the sides where the generator and the receptor are facing each other. Broadside coupling is another way, where it occurs when the signal conductors are broadside faced to each other in different layers with reference planes above and below these signal conductors. Coupling of the signals from the generator to the receptor can occur through capacitive coupling or inductive coupling. Capacitive coupling, also known as electrical coupling, occurs due to the difference in the characteristic impedance of the generator (usually 50 or 100 §Ù) and its heavy load (1 k§Ù or more) which results in high voltage difference between the generator and the reference conductor (ground). This leads to the creation of a charge across the generator and the receptor-facing sides and finally results in the electric field coupling between them. On the other hand, inductive coupling, also known as magnetic coupling, occurs when the load is less than the characteristic impedance of the generator, and this thereby results in a heavy current flow through the generator which in return results in a strong magnetic field around itself and so leads to magnetic coupling to the receptor. The aim in this thesis is to measure both the capacitive and inductive coupling load¡¯s impacts on both the edge coupling and the broadside coupling models through crosstalk on the receptor. This thesis starts with the background and corresponding theory and equations to the crosstalk coupling. Later on it tests both the edge- and broadside coupling models with different physical properties exploitation. Inductive and capacitive loads are used to measure the resulting crosstalk coupling. Particularly to see the effect of capacitive and inductive coupling in reality in multi layered PCB, a Sbclin (Broadside coupled striplines) model has been used with different angular placement of the generator. Finally mclin physical models are compared with the simulated models and corresponding differences are discussed. It can be concluded that crosstalk effect increases or decreases with physical properties exploitation. Crosstalk also increases with the wrong termination of the load.