Current landing and braking systems are associated with the approach, flare and rollout. Automatic and independent brake systems prevent skidding but do not restore the aircraft to the original trajectory. None use the normal aerodynamic surfaces to augment braking effectiveness to steer the aircraft during sudden changes in runway surface conditions. Many aircraft accidents occur during landing. The task of bringing the aircraft to a safe taxing speed from touchdown in variable weather conditions is the most difficult manoeuvre that a pilot has to make. There is no opportunity to recover or reattempt the manoeuvre. It is the only phase of the aircraft operation that has not been effectively improved through the use of autopilot control systems. Improving this regime of operation through the use of formally redundant aerodynamic control surfaces is the subject of this thesis. This thesis describes the development and testing of a controller, auto-pilot and ABS combination that uses ailerons to control the normal loading differential between the main gear of a B747-100 for the purpose of increasing the directional control so that is it possible to either minimising the centre line off-set or to maintain heading of a landing aircraft. The aileron based differential nonnal loading controller uses the brake line pressure differential as an input variable to control the ailerons during touchdown. During the II maximum braking case, the brake line pressure is proportional to the difference in runway friction coefficient, normal loading, and brake disk stack friction coefficient. Landing aircraft are extremely non-linear in function. To overcome this, a model and Controller that generates the appropriate non-linear mathematical description of the aircraft during the landing phase and generates an effective controller that effectively generates an increase in normal gear force on touch down of 100% and thereby allowing the aircraft to be controlled in direction during hazardous conditions was developed. The outcome of the work is that the use of a control scheme and unconventional use of ailerons can significantly improve aircraft landing characteristics during adverse landing weather conditions and reduce the number of accidents. Current advances in future aircraft design are tending towards tailless aircraft such as Boeing's Blended Wing Body aircraft and a similar study by Airbus. These aircraft do not have sufficient rudder or engine yaw control at landing speeds. This work provides a method of steering the aircraft from touchdown to taxi speed through normal force and brake augmentation.

Strengthening of existing structures has become an important aspect of civil engineering. Various methods exist and have been developed in the last few decades one of which has become increasingly popular- strengthening using fibre reinforced polymers. Their excellent mechanical properties and resistance to different environmental conditions make them a viable alternative to the traditional materials like concrete and steel. In this study the effect of elevated temperatures on the behaviour of FRP strengthened reinforced concrete beams is investigated. The behaviour of reinforced concrete beams strengthened with FRF laminates has been investigated by different researchers in the last two decades. Ultimate load, failure modes and improved techniques for strengthening have been the main areas of interest. As a result of the extensive research several classifications and design guidelines have been proposed to ensure better performance and prevent premature failures of the systems. One important aspect of the strengthening is the susceptibility of polymers to significant and rapid reduction of their strength when exposed to elevated temperatures and fire. Little research has been done up-todate on the residual properties of FRP strengthened systems after heating and cooling. Three experiments have been conducted for the purpose of this study. The bond strength of CFRP strengthened systems is first investigated for temperature range of 20°C to 300°C. The behaviour of small-scale strengthened beams during the heating process is presented next. The third experiment is then designed to determine the residual flexural capacity of the heated and cooled minibeams. The results are presented and compared indicating residual strength of the systems to 30% compared to their performance at room temperature

No description available.

This report looks at the possibility of designing a universal adapter for Flat Blade windshield wipers in cooperation with European Automotive Supplier AB. To understand and see if this is possible, a research and an extensive patent search where done. Then to add structure to the project a Ganttschematic were developed. To generate good and solid ideas, different methods for product development were looked upon. When a method was chosen and applied, a series of concepts emerged. Now the focus was to design and construct all the pieces. The desired manufacture procedures were looked upon as well as materials. Lot of time where spent on designing a lock mechanism to meet the demands European Automotive Supplier AB hade given. To choose the right concept the team used a set of selection matrix for the different ideas. After the choices were made, different prototypes were made of the concepts. Then they were tested, and improvement on them was done to make the end product better.

Det här examensprojektet har utförts på Volvo CE, Hauler & Loader Division, Arvika. Projektet ingick som ett avslutande moment i maskiningenjörsprogrammet vid Karlstads universitet. Volvo i Arvika tillverkar hjullastare vilket man har gjort sedan mitten av 60-talet. Fabriken har idag ca 1150 anställda som tillsammans levererar över 6000 hjullastare per år. Produktionsvolymen i Arvikafabriken ökar allt mer vilket medför att ett behov av många investeringar för att klara denna volymtillväxt har uppstått. Den huvudsakliga tillverkningen på svetsavdelningen består av fram- och bakramstillverkning. Problemet är att tillverkningen är trångbodd och att vissa ramflöden är i behov av förbättring. Projektets uppgift bestod av att undersöka möjligheter och konsekvenser av att installera två nya svetsrobotar i befintlig byggnad och på sikt skapa en separat framram resp. bakramsverkstad. Arbetets huvudmål är att få höjd kapacitet i svetstillverkningen av ramar. Resultatet av projektet visar att möjlighet finns att installera två nya svetsrobotar i de befintliga lokalerna, en robot för framramsvetsning samt en för bakramsvetsning. Ramtillverkningen är separerad med en verkstad för framramar i byggnad 1 samt en verkstad för bakramar i byggnad 2. (se bilaga 8, 50 och 51). Flera flöden har förbättrats genom att arbetsstationer har flyttats vilket i sin tur har inneburit mindre transportbehov i verkstaden. Uppdelningen av tillverkningen av fram- och bakramar har lett till ett tydligare flöde. De nya flödena syns i produktionsscheman och layoutflödesscheman (bilaga 52-69). Kostnaden för att genomföra projektet uppskattas till omkring 26 milj. kr. Ett ytterligare koncept, ”koncept 2”, har utretts som innehåller en större utbyggnad av bakramsverkstaden för att klara en större expansion av tillverkningen. Det kommer att kosta ca 38 milj. kr. / This master’s thesis was performed at Volvo CE, Hauler & Loader Division, Arvika. The project was a part of the Mechanical engineering program at the University of Karlstad. Volvo in Arvika is manufacturing wheelloaders and has done that since back in the sixties. Today they are about 1150 employees who together deliver over 6000 loaders a year. The production volume at the Arvika-plant is increasing and therefore there is a need for new investments in the plant. At the plant’s welding department the main manufacturing is the welding of front- and rear frames. The problem is that the manufacturing is cabined and some of the frame flows is in need of improvement. The task of the project was to examine the possibilities and identify the consequences of installing two new welding robots in the existing building and create separate front and rear frame workshops. The main reason for that is to reach a higher capacity in the manufacturing of frames. The result of the project shows that there are possibilities to install two new welding robots in the existing building, one for front frame welding and one for rear frame welding. The frame manufacturing has been separated with a workshop for front frames in building 1 and a workshop for rear frames in building 2 (see appendices 8, 50 and 51). Several flows has been improved due to workstations have been moved resulting in less need of transports in the workshop. The separation of front and rear frame manufacturing causes the flow of frames to be more clear and visible. The new flows are shown in production diagrams and layout-flow diagrams (see appendices 52-69). The cost for going through with the project is estimated to around 26 million sek. An additional concept, “concept 2”, has been investigated which contains an extended workshop for rear frames to manage a larger expansion of the production. It will cost around 38 million sek.

I arbetet görs en jämförelse mellan platsbyggda- och prefabricerade våtrum. Jämförelsen görs utifrån kriterierna ekonomi, kvalité och miljöpåverkan.

Taper making of boat masts is currently made with high work- and cassation costs. The main reasons are complex settings and varied demand, another is the craft like production method which makes the fixture use low. Due to a higher demand when new masts are being produced the work cost will sink relative to the turnover given that the workforce is unchanged. This assumes a higher productivity in the fixtures. To adapt the production to a higher demand and lower cassation costs measures will have to be made. A measure related to lower cassation costs is standardisation of the rail steering. To reduce the time for taper making the measure preloading is the single most affecting measure. The production of boat masts varies highly over the year with a top rate in spring and bottom rate in the winter. Taper making is also very craft like which makes the volume flexibility low due to the skill of the operators. Currently there are three operators who fully possess the ability. The others, mainly at another function of the mast division, can only relieve the taper operator. Among the suggested measures open fixture is mentioned in order to reduce the handling of masts. Currently, when handling longer masts, an AGV will have to be stopped by the operator in due to avoid collision. This problem occurs because of the fact that the fixture is being loaded in the length direction of the mast. With a new fixture, capable of cross loading, the time for handling will be reduced but the amount of time is difficult to estimate. / Koning av båtmaster görs i dagsläget med höga kassations- och arbetskostnader. De huvudsakliga orsakerna är svåra inställningar och varierad efterfrågan, en annan orsak är att tillverkningen är hantverksmässig vilket ger lågt fixturutnyttjande. I takt med att nya masttyper börjat konas kommer arbetskostnaderna minska relativt intäkterna givet att de nya volymerna kan hanteras med nuvarande bemanning. Detta förutsätter högre produktivitet i fixturerna. För att anpassa koningen mot en högre produktionsvolym och lägre kassationskostnader krävs åtgärder. Ett viktigt åtgärdsförslag för minskade kassationskostnader är standardisering av skenornas krökning. För tidsbesparing är åtgärden förspänning av master den enskilda åtgärden med störst påverkan. Tillverkning av master varierar kraftigt med säsong, där vår utgör topp medan vintern utgör dal. Då all koning sker mot kundorder råder därmed en viss överkapacitet. Tillverkningen är hantverksmässig vilket medför låg volymflexibilitet då koning kräver utbildad personal. I dag finns endast 3 operatörer vid mastavdelningen som behärskar koning, övriga kan visserligen avlasta men för att koning skall kunna utföras krävs närvaro av någon av dessa tre. Bland åtgärdsförslagen nämns öppen fixtur vilket kom till för att förenkla hanteringen av master. I dagsläget måste en AGV-vagn, som används vid pressens verktygshantering, stoppas av operatör vid koning av längre master. Detta för att masten måste laddas i längdled vilket kräver extra utrymme. En öppen fixtur förenklar förflyttningen av mast avsevärt men vilken tidsbesparing som nås är svår att uppskatta.

Syftet med detta examensarbete är att visa på hur Totebo AB kan effektivisera material-hanteringen runt en UV-lackeringslina genom att införa en automatisk lösning. En automatisk lösning skulle också minska det monotona arbete som dagens lösning kräver. Totebo AB agerar som underleverantör inom planmöbelindustrin i Sverige och har en väldigt stor produktmix. Planmöbler är uppbyggda av platta träfiberskivor som monteras ihop till kompletta möbler. Ett förslag på lackeringslinans layout har tagits fram där den stora utmaningen har varit att anpassa den automatiska utrustningen till att klara alla 9000 produktvarianter samtidigt som lösningen måste vara driftsäker och ekonomiskt försvarbar. Arbetet har även utmynnat i dessa slutsatser: • Den största produktionsökningen fås genom att maximera utnyttjandet av lackeringslinans bredd vilket inte kan göras i dagsläget • Automatisk in- och utmatning för lackeringslinan ger följande fördelar: o Stor procentuell ökning av produktionen o Möjlighet till att kunna köra linan snabbare i framtiden o Inget monotont arbete för operatörerna o Driften av lackeringslinan blir mindre operatörsintensiv • Utveckling av en metod samt utveckling av en maskin för att kunna separera på träfiberskivor som ”limmats” fast i varandra efter kantlackering

Detta examensarbete är utfört vid Korroterm AB som är beläget i Linghem utanför Linköping. Företaget är en mindre underleverantör med cirka 25 anställda som specialiserat sig på ytbehandling av metalldetaljer med termoplast. Syftet med detta arbete har varit att undersöka möjligheterna med induktionsuppvärmning för deras produktion och utveckla en effektiv utrustning som tillämpar denna teknik. Ett mål är att utrustningen skall klara att automatiskt hantera och belägga detaljer av en mindre skokartongs (med mått kring 30*30*30cm) storlek. Genom litteratur, muntlig kommunikation och praktiskt arbete har studier inom induktionsteknik och termoplastbeläggning utförts. Inriktningen på dessa studier har varit att få förståelse för grunderna, hur de fungerar och vilka begränsningar som finns med teknikerna. För framtagning av konceptlösningar till utrustningen har ”Systematisk Konceptutveckling” av Ulf Liedholm används med en viss modifikation. Då problemet lätt blivit väldigt stort och komplicerat föll det sig naturligt att en uppdelning till delsystem gjordes, vilket gav en bättre överblick av hela systemet. Ett antal koncept togs fram för varje delsystem för att sedan sammanställas till en konceptlösning för hela utrustningen. Som resultat av examensarbetet ges en rekommendation till företaget Korroterm AB att fortsätta utveckla befintlig utrustning som tillämpar induktionsuppvärmning istället för att investera i en ny. Efter en undersökning av de detaljer som idag finns i produktionen framkom det gällande geometri, antal och frekvens att inga lämpliga detaljer fanns för denna utrustning. Det visade sig dock att det fanns en potential för tillämpning av induktionsuppvärmning för mindre detaljstorlekar. En studie för att undersöka möjligheterna att belägga dessa i nuvarande utrustning bör utföras. / This thesis work has been written on assignment of Korroterm AB. The company is situated in Linghem which is located just east of Linköping. Korroterm AB is a small subcontractor with around 25 employees who is specialised in surface treatment with thermoplastic coatings on metal objects. The purpose with this thesis work has been to study induction heating to learn what possibilities it offers for the production on Korroterm AB and to implement the technique in an automated production line. The goal for this equipment is that it should be able to handle parts with an estimated size of a small shoebox (30*30*30cm). Thru a study of literature, verbal sources and practical work an understanding of thermoplastics and induction heating has been made. The focus point of the study has been on the basics, how they work and what limits the techniques have. A method in ”Systematisk Konceptutveckling” by Ulf Liedholm has been used with a small modification. The solution for the whole problem would easily become very large and complicated therefore it was divided in to smaller parts which gave a better view of the system. Several concepts where then developed for each part of the system and then assembled into a concept for the whole equipment. As a result of this thesis a recommendation was given that the company Korroterm AB should keep developing the existing equipment that implements induction heating instead of investing in a new. After an investigation for suitable parts in the production today with regards to size, number and frequency it became clear that no suitable parts for the equipment were to be found. However a potential for implementing induction heating were discovered for the smaller detail sizes. A study of these should be made to see the possibilities of treatment in existing induction heating equipment.

One major limitation in the use of externally pressurized air bearings (EPB) is their susceptibility to vibrations problems. The most destructive vibration that develops in a gas bearing is self-excited whirl, which commences when the damping force in the bearing becomes zero. The main aim of this research was to undertake a theoretical investigation of cylindrical whirl in a balanced vertical axis EPB, and ways of delaying its onset. In order to do this, it was necessary firstly to find the bearing static stiffness and damping coefficients by means of a compressible flow analysis of the gas. To do this, by employing Mathematica, a novel approach used the 'shooting method' in order to solve the governing differential equation (which included functions of a complex variable). The results obtained compared very favourably with previous theoretical published work that had employed finite difference methods. Having found the bearing coefficients, it was possible to solve the bearing dynamic differential equations and thus create stability maps. This procedure was carried out on various bearing arrangements aimed at raising the stability threshold. These included: A series arrangement involving a non-rotating externally pressurized sleeve round the rotor as well as a series arrangement in parallel with the main bearing. The series-parallel configuration resulted in a bearing with a threshold speed and stiffness between the extremes of a simple EPS and a series EPB, all three designs being of the same length. An optimum adjustment of the series-parallel geometry, created threshold speeds three to four times that of a simple version. This in itself was an excellent achievement. Finally, a further increase in threshold frequency, up to seven times that of an equivalent simple EPB, was attained by an additional novel design round the sleeve of a passive eddy current magnetic damper.