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  • 1.
    Absalyamova, Viktoriya
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Energy Analysis within Industrial Hydraulics and Correspondent Solar PV System Design2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Energy efficiency and renewable energy use are two main priorities leading to industrial sustainability nowadays according to European Steel Technology Platform (ESTP). Modernization efforts can be done by industries to improve energy consumptions of the production lines. These days, steel making industrial applications are energy and emission intensive. It was estimated that over the past years, energy consumption and corresponding CO2 generation has increased steadily reaching approximately 338.15 parts per million in august 2010 [1]. These kinds of facts and statistics have introduced a lot of room for improvement in energy efficiency for industrial applications through modernization and use of renewable energy sources such as solar Photovoltaic Systems (PV).The purpose of this thesis work is to make a preliminary design and simulation of the solar photovoltaic system which would attempt to cover the energy demand of the initial part of the pickling line hydraulic system at the SSAB steel plant. For this purpose, the energy consumptions of this hydraulic system would be studied and evaluated and a general analysis of the hydraulic and control components performance would be done which would yield a proper set of guidelines contributing towards future energy savings. The results of the energy efficiency analysis showed that the initial part of the pickling line hydraulic system worked with a low efficiency of 3.3%. Results of general analysis showed that hydraulic accumulators of 650 liter size should be used by the initial part pickling line system in combination with a one pump delivery of 100 l/min. Based on this, one PV system can deliver energy to an AC motor-pump set covering 17.6% of total energy and another PV system can supply a DC hydraulic pump substituting 26.7% of the demand. The first system used 290 m2 area of the roof and was sized as 40 kWp, the second used 109 m2 and was sized as 15.2 kWp. It was concluded that the reason for the low efficiency was the oversized design of the system. Incremental modernization efforts could help to improve the hydraulic system energy efficiency and make the design of the solar photovoltaic system realistically possible. Two types of PV systems where analyzed in the thesis work. A method was found calculating the load simulation sequence based on the energy efficiency studies to help in the PV system simulations. Hydraulic accumulators integrated into the pickling line worked as energy storage when being charged by the PV system as well.

  • 2.
    AL-Shareefi, Hussein
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Neutral network corrosion control by impressed cathodic protection2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
  • 3.
    Alzén, Axel
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Effektivisering av en produktionsprocess: Analys och förbättringsförslag till en verkstadsindustri2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Isakssons AB is the manufacturer of custom-designed products and efficient solutions in stainless steel, constructional metalwork and environmental technology. The company is currently going through an expansion phase, which leads to greater requirements for the production. In order to cope with this expansion, they have chosen to rebuild their premises, and these changes must be adapted for the production to enable further growth for the company.  The purpose of this study is to give improvement proposals to a more effective production process at a manufacturing company with varying products. In order to create understanding for the process, flowcharts, process mapping’s and time studies have been executed. By performing a zero state analysis, improvement opportunities have been discovered, and changes have been proposed from these.  The results from the frequency studies show that the operators spend a lot of time on work that is non valuable for the product. By creating more workstations for manufacturing and introducing visual workplace aids, these non valuable activities can be reduced. Furthermore, the re-locating of machines and inventory have been suggested, in order to create an easier flow through the premises.

  • 4.
    Andersson, Carolin
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Från oljehydraulik till vattenhydraulik: Utveckling av ett portabelt hydraulikaggregat2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The report describes the work behind the development of a portable water hydraulic system that will be used to open and close a floodgate if the regular hydraulic system used for this is inoperative. The aim was to achieve the same performance as a portable oil hydraulic system, which could be achieved with the exception that oil could not be avoided completely.

    The project was carried out in collaboration with Mobin Hydraulic AB, which develops hydraulic systems for opening and closing floodgates. Mobin specializes in water hydraulics, which is a more environmentally friendly alternative compared with oil hydraulics. As an interest was also on the market where eco-friendly solutions were increasingly demanded, the portable water hydraulic system was of interest to both Mobin and the market.

    The problems were about how the flow was to be controlled and what pump and hydraulic engine could be used in the system. The components would be adapted to water and harmonize with a predetermined petrol engine while delivering desired performance.

    By studying hydraulics and water properties and impact on the hydraulic system in combination with taking part in Mobin's experience, an image of the system's structure and components was created.

    Based on a component search, calculations and design of concepts a concept selection was made where the selected components, component dimensions and placements in the system were displayed. Due to the limited availability of water hydraulics components, gearboxes were used to get the right speed and torque. One of the gearboxes contained oil and therefore it was not possible to completely avoid oil use.

  • 5.
    Andersson, David
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Effektiviserad balresthantering2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Arctic Paper Grycksbo is a company that produces paper. The pulp which is used to produce the paper is purchased. The pulp arrives to Arctic Paper in bales which are wrapped with something called wrapping paper. The wrapping paper is similar to the pulp inside of the wrapping, which means it can be used to produce paper. Damage on the bales due to transportation and handling leads to usable pulp being removed from the bales which falls to the ground. The pulp which is removed from the bales remains on the ground (pulp rests) until workers pick it up and place it in a recycling container. This container is then to be emptied and the pulp recycled, if the procedure is working as intended.

    The current recycling procedure has proven to be in need of improvement. This has led to a need of an improvement, either by improving the method/procedure to recycle the pulp, or through preventing the pulp being removed from the bales in the first place. The purpose with this thesis is to investigate- and suggest solutions to which possibilities for improvements there is.

    An investigation of which alternative to achieve this improvement is the better- and calculations of the annual recycling potential has been done. Different concepts has then been generated based on information gathered from the investigation and calculations.

    A new way of handling the pulp which is to be recycled has been suggested in consultation with technicians from Arctic Paper. The suggested new method/procedure enables easier recycling in terms of manual labour and reduces the total costs of the procedure.

  • 6.
    Andersson, Grober
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Framdrivningssystem för Articulated Funiculator i SL deep station: Framtagning och urval av koncept2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out in collaboration with Tyréns project Articulated Funiculator developing emerging vertical transport which in this case is meant to be used in SL deep station in Stockholm.The aim of this work is to is to develop propulsion concepts for Articulated Funiculator and through concept selection sort out the optimum for SL deep station. To achieve the purpose, studies have been undertaken of literature and reports followed by workshops and customer surveys. Then a pairwise comparison has been made, QFD, concept generation and a two-stage concept selection made.Result is that the optimum propulsion system for SL deep station in Stockholm is a system of linear motors mounted between the tracks.

  • 7.
    Andersson, Martin
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Konceptutvärdering av gjutformshantering: Utformning och dimensionering av entresolplan enligt eurocode2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ABB Components in Ludvika manufactures bushing for transformers. During the manufacturing, several steel molds are used. The molds are stored on a steel mezzanine floor constructed by several columns and beams. Due to that the amount of these molds has increased the existing way to handle and store these molds is impaired based on a safety and effectivity perspective. ABB have received two concept that propose how these problems could be solved. One is based on a solution with a special floor made of spheres. The other one is from a company called ELE Engineering AB that proposes a conveyor belt that is attached to the underside of the mezzanine floor. This will enable for 60 new molds to be stored. This work aims to evaluate how the mezzanine is affected by the weight of the new molds, how it should be strengthened and to evaluate which of the concept is recommended.

    Based on a series of simulations it is suggested that the mezzanine floor is reinforced with 21 new beams and 5 pillars to cope with the stresses the molds give rise to. The European standard EN-1090 has been the basis for how these columns and beams should be designed and attached. Further the two concepts will be evaluated based on effectivity, price and safety. Based on a concept evaluation ELEs solution is recommended despite lack of information about the floor with spheres.

  • 8.
    Argårds, Andreas
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Kartläggning av ytjämnheten efter kallvalsning för olika kallvalsade kvalitéer samt trimvalsningens påverkan på ytjämnheten2010Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Syftet med detta arbete är att kartlägga ytjämnheten på stålbanden efter kallvalsning samt hur den erhålla ytjämnheten påverkas av trimvalsningen. Detta för att undersöka om det är möjligt att minska ner användandet av någon valsyta i Tandemverket vid SSAB Borlänge. Genom att mäta ytjämnheten på stålband av olika kallvalsade kvalitéer efter kallvalsning och trimvalsning, mäta ytråheten på texturerade valsar före och efter användning samt genomföra test med nya ytkombinationer har ett antal resultat genererats. Två test där Docol 200 band som skulle levereras med bandyta 23 valsades med en grövre yta i Tandem (valsyta 48 istället för 34) än vad som är brukligt och sedan trimvalsades med ordinarie valsyta visade att det är möjligt att klara kraven på Ra-värde för bandyta 23 även på band som kallvalsats med en grövre valsyta än i vanliga fall. Dock är det inte säkerställt att kraven för yta 23 alltid kan uppnås på band kallvalsade med grövre valsyta. Trimvalsning med valsyta 57 i den kontinuerliga glödgningslinjen har ingen betydande påverkan på ytjämnheten för Docol 600 & 800 DP, dock påverkar den ytan för Docol 200 eftersom att dessa band har mindre spridning i Ra-värde efter trimvalsning jämfört med innan. Trimvalsning med valsyta 57 höjer toppantalet på bandens yta. Band av en högre hållfasthetsklass får lägre Ra-värde jämfört mot mjukare stålsorter. Band med stor tjockleksreduktion i Tandem får lägre Ra-värde, detta gäller speciellt Docol 200 där trenden är tydligast. Ra-värdet på de texturerade valsarna i Tandem sjunker mycket i början när de används, test har visat att redan under kalibreringen kan Ra-värdet minska med 0,8 µm – 1,3 µm.

  • 9.
    Awda, Fadi
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Omkonstruktion av luftkylning för enfasreaktor2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The task of this thesis was to review the failure of three reactor units that were caused by

    moisture and dirt that entered the reactor through the cooling system. The purpose was to find

    a solution that would allow the reactor to stay on site without being affected by moisture or

    dirt.

    The company did not have resources to provide a quick solution for the project and therefore

    time and money is a big factor. The specifications from the customer strictly forbid any

    assemblies outside of the site and that nothing in their surroundings are affected by the work.

    To come to a conclusion the reactor had to be broken down to pieces and after that concepts

    were made to affect the environment around the reactor or the design.

    The safety that the customer requires is that the cooling equipment should be at least as

    efficient as the current one and that we make sure that this type of failure will not be repeated.

    The problem was solved by adding a temperature device that measures the heat in the reactor

    that controls the fan and redirects the airflow inside the reactor through redesign to make sure

    that moisture and dirt won't occur inside the reactor – to avoid internal flash over.

  • 10. Bergdahl, Anders
    et al.
    Kenger, Patrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Onori, Mauro
    The use of DFA/DFAA Analysis for early start up of Assembly System Design2005In: International Forum on Design for Manufacture and Assembly, Providence - Warwick, Rhode Island, USA, 2005Conference paper (Refereed)
    Abstract [en]

    Assembly system design and development is still characterized by uncertainty resulting in increased lead-times in the design and development process and ineffective assembly system solutions. One important reason for this situation is that companies do not use methods for assembly system design and development in the extent needed, simply because there are no methods applicable. Methods developed by academia are still too complicated and not distinct enough, in quantifiable means, concerning the link to assembly system design. In this research four case studies in four different companies have been executed with the objective to find out more about how industry handles assembly system design and if there are possibilities for improvement. The findings in the case studies unambiguously point out that there is a need for a guideline supporting the assembly system design, development and re-design phases. The case studies do also indicate that the information from DFA/DFA2 analysis, valuable for the assembly system design process, is not used within the subsequent assembly system design phase. An assembly system design guideline that uses information and results from the DFA work, together with internal and external demands, would facilitate the assembly system design and development process. This paper will introduce a framework for such a method.

  • 11.
    Caron, Simon
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Accelerated aging of thick glass second surface silvered reflectors under sandstorm conditions2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Concentrated solar power systems are expected to be sited in desert locations where the direct normal irradiation is above 1800 kWh/m2.year. These systems include large solar collector assemblies, which account for a significant share of the investment cost. Solar reflectors are the main components of these solar collector assemblies and dust/sand storms may affect their reflectance properties, either by soiling or by surface abrasion. While soiling can be reverted by cleaning, surface abrasion is a non reversible degradation. The aim of this project was to study the accelerated aging of second surface silvered thick glass solar reflectors under simulated sandstorm conditions and develop a multi-parametric model which relates the specular reflectance loss to dust/sand storm parameters: wind velocity, dust concentration and time of exposure. This project focused on the degradation caused by surface abrasion. Sandstorm conditions were simulated in a prototype environmental test chamber. Material samples (6cm x 6cm) were exposed to Arizona coarse test dust. The dust stream impacted these material samples at a perpendicular angle. Both wind velocity and dust concentration were maintained at a stable level for each accelerated aging test. The total exposure time in the test chamber was limited to 1 hour. Each accelerated aging test was interrupted every 4 minutes to measure the specular reflectance of the material sample after cleaning. The accelerated aging test campaign had to be aborted prematurely due to a contamination of the dust concentration sensor. A robust multi-parametric degradation model could thus not be derived. The experimental data showed that the specular reflectance loss decreased either linearly or exponentially with exposure time, so that a degradation rate could be defined as a single modeling parameter. A correlation should be derived to relate this degradation rate to control parameters such as wind velocity and dust/sand concentration. The sandstorm chamber design would have to be updated before performing further accelerated aging test campaigns. The design upgrade should improve both the reliability of the test equipment and the repeatability of accelerated aging tests. An outdoor exposure test campaign should be launched in deserts to learn more about the intensity, frequency and duration of dust/sand storms. This campaign would also serve to correlate the results of outdoor exposure tests with accelerated exposure tests in order to develop a robust service lifetime prediction model for different types of solar reflector materials.

  • 12.
    Dahlblom, Linus
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Utveckling av infästningsplattor för montering av solpaneler på tätskiktstak2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Solar panels are becoming more and more common. Unfortunately, there are currently no solutions adapted to secure the panels on membrane roofs. Instead, they are attached with methods that are meant for personal safety, which are oversized for the purpose. In this work a mounting plate that is adequately sized for mounting solar panels is developed. This is done using a product development process that is designed to define the loads on the panels and from there develop a solution which is shaped and sized for the purpose. The result is a product that withstands the loads with a good margin to a considerably lower price than the original solutions.

  • 13.
    Darth, David
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Värmehantering - Datorstödd dimensionering av kapsling för batteriladdare2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis-work, the possibility of integrating a heat sink in the encapsulation of a batterycharger has been investigated. To manage the thermal load, a plate-finned heat sink has been dimensioned. Two design concepts have been developed, with two different heat sinks integrated in the design. The concepts thermal performance has been simulated in Solidworks Flow Simulation to identify surface-temperatures, component-cooling, flow conditions and radiation. The results from the calculations and the simulations shows that both of the concepts, at an ambient temperature of 30ᵒC, performs a sufficient heat flux to keep the internal components under 93ᵒC. The battery-charger’s encapsulation temperature would not exceed 54ᵒC under these conditions. For further development, a concept with the heat sink covered by a “lid” has been recommended.

  • 14.
    Domkin, Konstantin
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Physically based models of metal plasticity2003Licentiate thesis, monograph (Other academic)
  • 15.
    Edlund, Johan
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Utveckling av en variabel oljepump för tävlingsmotorer2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Racing engines often use dry sump lubrication systems in which pumps supply oil to and fromthe engine via an external tank. Dry sump pumps consist of several separate displacement pumpstages that are driven by the crankshaft of the engine, usually via a reduction gearing. Asignificant portion of the power taken from the crankshaft by a dry sump pump is due to thepump stage force feeding the engine with oil from the external tank due to the supply pressurerequired by the engine. So if the power required to drive the pressure stage could be reduced itwould have a large impact on the total power used by the dry sump pump. One way to reduce thepower used by an oil pump is to replace the regular displacement pump with a pump having avariable displacement. Since the oil pump is driven at a speed that is proportional to the speed ofthe crankshaft the pump has to be dimensioned with a high displacement to provide adequate oilflow and pressure at low engine speeds leading to a pump that is oversized at high engine speeds.Normally the excess capacity of the pump at high speed is dealt with by a pressure relief valve,but this does little to reduce the power used by the pump. While variable displacement pumpsare becoming more and more common among production engines having a wet sump none haveso far been used in a dry sump lubrication system for a racing engine. With a racing engine acompact size and low weight are important, particularly when regulations mandate the maximumsize of the pump such as in NASCAR. To fit with NASCAR regulations and it’s 3.5 x 3.5 x 10inch maximum dimensions a variable vane pump using a tilting cam ring to control displacementwas selected as a replacement for the gear pump with pressure relief. While the standaloneprototype met the 3.5 x 3.5 inch requirement, the pump stage was longer and heavier than thegear pump it was supposed to replace.

  • 16.
    Efraimsson, Kim
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Development of foldable center section for train coupler2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To safely convey trains in an urban area, a number of factors must be considered. One of these is that parts pointing out from the cart may cause harm to people or the train’s surroundings. An example of such a part is the train coupler located in the front or back of the cart. To avoid this problem, train couplers with the ability to be folded and hidden behind a hatch on the cart are used. To fold the coupler, a center section with a folding joint and locking mechanism is used.

    The main problem with existing foldable center sections is that over time, a play develops in the joint and locking mechanism as a result of wear damages. The play enables the coupler to move in an undesirable fashion which causes, among other things, the train ride to be unpleasant for passengers.

    The purpose of this project was to develop a new concept for a foldable center section which aims to reduce or eliminate the wear damages and play mentioned above. This report describes the development process, which theories were used, which methods were used and the final result of the project.

    The result of the development project is a concept for a new variant of foldable center section with associated 3D models, overview drawings and a validation plan for a finished prototype. The developed concept differs from existing solutions in many ways. The goal to reduce wear damages and its consequences was achieved with the new concept. However, the result is not optimal. This is discussed in the conclusion of the report.

  • 17.
    Elemam, Aboubker
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Development of a ESES Solar Thermal Lab on Full Scale System2011Independent thesis Advanced level (degree of Master (One Year)), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    The main aim of this project is to develop an ESES lab on a full scale system. The solar combisystem used is available most of the time and is only used twice a year to carry out some technical courses. At the moment, there are no other laboratories about combisystems. The experiments were designed in a way to use the system to the most in order to help the students apply the theoretical knowledge in the solar thermal course as well as make them more familiar with solar systems components. The method adopted to reach this aim is to carry out several test sequences on the system, in order to help formulating at the end some educating experiments. A few tests were carried out at the beginning of the project just for the sake of understanding the system and figuring out if any additional measuring equipment is required. The level of these tests sequences was varying from a simple energy draw off or collector loop controller respond tests to more complicated tests, such as the use of the ‘collector’ heater to simulate the solar collector effect on the system. The tests results were compared and verified with the theoretical data wherever relevant. The results of the experiment about the use of the ‘collector’ heater instead of the collector were positively acceptable. Finally, the Lab guide was developed based on the results of these experiments and also the experience gotten while conducting them. The lab work covers the theories related to solar systems in general and combisystems in particular. 

  • 18.
    Engström, Fredrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Ökad tillgänglighet i maskiner för skärande bearbetning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this work is to develop principles for an approach that can continuously increase the availability of the company's machines. By studying the theory of this subject, measurements has designed to produce what the companies availability is in their four main machines. The approach shown in this work is based on three different parameters that affect the value. It is production dependent stop, maintenance dependent stop and resource shortages. By doing this way, the company can be able to have a clearly arranged data to work with, which they easily can see how to enhance availability. It has also been raised a little bit about the reliability and the mean down time where it is also possible to obtain facts to increase availability. What this work have come to is that it can be very different things that affect availability negative but by doing it this way they can see these things and put into action after that.

  • 19.
    Fahlvik, Adam
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    3D-skrivare för prototyptillverkning i plast 20162016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis project has been to investigate which new 3D printing equipment

    would be of greatest use for the company Dalelven Produkutveckling AB.

    Through interviews with the company's project leaders the company's needs for new equipment has been identified.

    Information about 3D printers, processingmethods and perihpal equipment has been gathered and sorted. With the support of theories from Quality Function Deployment 3D printers have been evaluated and sorted in categories in accordance with the company's needs.

    Dalelven need to be able to create prototypes in several kinds of plastic. In comparison between the most interesting 3D printers Stratasys polyjet printers from their Objet Connex series got the highest score (exluding HP's “Multi Jet Fusion” printers that not yet are for sale).

    In a comparison between 3D printers that print with thermoplastics it was observed that a couple of relatively unknown companies is producing 3D printers with in some categories better specifications than the established companies alternatives.

  • 20.
    Folmerz, Mattias
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Oljeläckage torkparti PM12: Utvärdering av oljeläckage i torkparti PM122017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stora Enso Kvarnsveden is a paper mill located at Dalälven in Kvarnsveden. The utility currently has two producing machines, and this study deals with one of them, which is PM12. At PM12 there is a problem with oil leaks in the machine's drying section. Leakage occurs through the bearing houses who are there to support the dryer's rollers. In this study, it has been investigated what the leakage is due to focusing on its bearing seals.

    The purpose of this study has been to investigate why leakage occurs and to generate concepts to reduce or eliminate leaks. The study has included various measurements and investigations to address the problem. A literature study has been conducted to identify causes and solutions. Concepts have been generated from the literature study as well as the measurements that have been taken.

    After this study it´s not fully realized why the leakage occurs, but it had come a long bit on the way. Proposals for continued work have been given, where it is recommended more specifically what kind of measurements that should be done and the concepts that should be further developed.

  • 21. Ginsburg, Alexander
    et al.
    Börjesson, Fredrik
    Erixon, Gunnar
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Size Ranges in Modular Products - A Financial Approach2004In: The 7th Workshop on Product Structuring – Product Platform Development, Chalmers University of Technology, Gothenburg, 2004Conference paper (Refereed)
  • 22.
    Hansson, Fredrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Tillämpad motoroptimering: Optimering av tillämpad BLDC-motor2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The report contains a description and analysis of a particular type of engine that is optimized for an electric single-passenger vehicle. Work is based on the existence of a developed prototype of the vehicle and also the engine but it cannot be considered to be sufficiently optimized for the purpose. The goal and the purpose of this report is to investigate the prototype's limitations and shortcomings and what specific target values are determined to be, if possible fulfilled. These are then used to analyze and develop an improved design.

    Specific software have been used to help in the work to make a model in 3D CAD and also to simulate the performance of a theoretical model. The accuracy of the simulated model cannot be verified as no real model has been constructed. The simulated model shows that there is great opportunity to improve performance while the design has been made smaller and lighter. The creation of a 3D CAD model also allowed that strength analyzes have been done on selected components that can be considered to be highly stressed. Thus, the structure has also been verified that it can work for the intended use without a risk of breakdown or wear out prematurely.

    Finally, an estimate of the cost of manufacturing was made that's very simplified but still provides an indication of how much it might be. The calculation is based on the values that the software generates by the input of material prices. To help further, a local company was contacted for a quote in order to provide a more accurate result. Then, it is only a rough estimate and since there is not an existing production line available there will be an estimated value. The estimated cost is still within reasonable values but it can still be improved. There is potential to optimize the cost and also the design further, but the aim of this work was to develop a product that meets the requirements which was fully achieved.

  • 23.
    Hassling, Magnus
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Löppönen, Pauli
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Simulering av olika underhållsstrategier inom processindustri2008Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Syftet med detta examensarbete är att utvärdera om simulering av flöden på en emballeringsavdelning kan vara till hjälp för att kunna planera in stopp av packmaskiner så att förebyggande underhåll kan utföras. Med hjälp av simulering har kölängder, kötider och beläggningsgrader hos emballeringsavdelningen kunnat predikteras. Genom att skapa olika hypotesgrundade scenarion i simuleringsmodellen har ett antal resultat genererats. Resultaten av simuleringarna har gett värdefull information till underhållsavdelningens planerare. Informationen bör kunna vara ett viktigt beslutsunderlag för att kunna avgöra vid vilka tillfällen som de planerade stoppen kommer att ge upphov till minst störning av driften. Arbetet har visat att simulering av flöden är ett bra hjälpmedel för att kunna planera in stopp för förebyggande underhåll. För att kunna uppfylla syftet har en simuleringsmodell skapats över emballeringsavdelningen. Genom studier av processer och genom informationshämtning från kunnig personal har en användbar modell kunnat skapas. Även studier av underhållsteorier och simuleringslitteratur har varit till hjälp för att kunna uppfylla syftet med detta examensarbete. De utförda analyserna bygger till stor del på rekommendationer hämtade från den simuleringslitteratur som studerats men även på tips och stöd från författarnas handledare som har lång erfarenhet inom området.

  • 24.
    Holmberg, Tommy
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Utformning av ett standardbibliotek: Fundament- och apparatkombinationsoptimering vid en HVDC-station2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis objectives was to assist with general optimizations and efficiency improvements regarding the development of an HVDC station. Through the optimization of work methods and the clarification of calculation document my thesis will show the possibility to free resources directly from the quotation and project stages. This methods has great potential to be applied to many of the future HVDC-projects that the company has the opportunity to win, and with the implementation of the LEAN tool: Continuous improvements, the methods have the future opportunity to be even more efficient.

  • 25.
    Höök, Therese
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Implementeringsplan för ett flexibelt produktionssystem vid Boggs Mekaniska AB2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med examensarbetet är att undersöka det nuvarande produktionssytemet och identifiera förbättringsförslag som skapar utrymme för en mer effektiv och flexibel produktion, och sammanfatta dessa i en implementeringsplan. En ökad flexibilitet i produktionen anses nödvändig för att i framtiden kunna möta efterfrågan som i framtiden kommer att ställa krav på snabbare leveranser.

    Vid kartläggning av nuvarande system framgår det att den genomsnittliga omställningstiden är lång inom produktionssystemet, vilket skapar problem då det råder stor artikelvariation hos Boggs Mekaniska AB. I och med de långa ställtiderna körs i dagsläget stora partier där seriestorlekarna varierar mellan 50 och 10000 stycken detaljer. Mycket utav den tillgängliga produktionstiden läggs i dagsläget på onödiga och icke värdeskapande aktiviteter som bedöms bero på en ostrukturerad arbetssituation för produktionspersonalen. Det råder även långa omställningstider vid flertalet maskiner. Produktionen är i stor utsträckning personalbunden och helt beroende av rätt operatör på rätt plats. Produktionsplaneringen upplevs bristfällig, främst beroende på otillräcklig kunskap i affärssystemet monitor, men även på grund av att omplaneringar och ändrade körordningar ställer till det i produktionen.

    För att hitta rätt lösning för produktionssystemet genomfördes en omfattande datainsamling i form av observationer, enkät, intervjuer, fokusgrupp, litteraturstudier, tidsstudier. Vidare kombinerades flertalet välkända förbättringsverktyg och metoder för att säkerhetsställa att rätt lösningar tillämpas utifrån den givna situationen. Några av de viktigaste analys- och förbättringsverktyg under arbetet gång har varit SMED analys och 5S och JIT.

    Arbetet resulterade i en implementeringsplan för hur arbete med 5S, smedanalys, och en ny layout bör se ut för att möjliggöra mindre partistorlekar, fler omställningar och ett ökat antal färdigställda ordrar på kortare tid, och på så vis göra produktionen mer flexibel. Vidare arbete bör genomföras främst enligt de steg som presenteras i JIT-modellen men även vad gäller produktionsplaneringen då den i dagsläget upplevs som bristfällande. Arbete med produktionsplaneringen anses ha betydande förbättringspotential gällande reducering av genomloppstiden.

  • 26.
    Iliev, Dimitar
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Discrepancies in solar irradiation data for Stockholm and Athens2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The aim of this study is to evaluate the variation of solar radiation data between different data sources that will be free and available at the Solar Energy Research Center (SERC). The comparison between data sources will be carried out for two locations: Stockholm, Sweden and Athens, Greece. For the desired locations, data is gathered for different tilt angles: 0°, 30°, 45°, 60° facing south. The full dataset is available in two excel files: “Stockholm annual irradiation” and “Athens annual irradiation”. The World Radiation Data Center (WRDC) is defined as a reference for the comparison with other dtaasets, because it has the highest time span recorded for Stockholm (1964–2010) and Athens (1964–1986), in form of average monthly irradiation, expressed in kWh/m2. The indicator defined for the data comparison is the estimated standard deviation. The mean biased error (MBE) and the root mean square error (RMSE) were also used as statistical indicators for the horizontal solar irradiation data. The variation in solar irradiation data is categorized in two categories: natural or inter-annual variability, due to different data sources and lastly due to different calculation models. The inter-annual variation for Stockholm is 140.4kWh/m2 or 14.4% and 124.3kWh/m2 or 8.0% for Athens. The estimated deviation for horizontal solar irradiation is 3.7% for Stockholm and 4.4% Athens. This estimated deviation is respectively equal to 4.5% and 3.6% for Stockholm and Athens at 30° tilt, 5.2% and 4.5% at 45° tilt, 5.9% and 7.0% at 60°. NASA’s SSE, SAM and RETScreen (respectively Satel-light) exhibited the highest deviation from WRDC’s data for Stockholm (respectively Athens). The essential source for variation is notably the difference in horizontal solar irradiation. The variation increases by 1-2% per degree of tilt, using different calculation models, as used in PVSYST and Meteonorm. The location and altitude of the data source did not directly influence the variation with the WRDC data. Further examination is suggested in order to improve the methodology of selecting the location; Examining the functional dependence of ground reflected radiation with ambient temperature; variation of ambient temperature and its impact on different solar energy systems; Im pact of variation in solar irradiation and ambient temperature on system output.

  • 27.
    Jansson, Anneli
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Kapacitetsförbättring med effektivare materialhantering2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To cope with anticipated future increase in production LogMax should improve material handling around the assembly. The questions that the study will answer are: How can LogMax streamline the assembly to meet the production increase? What methods can be easily implemented to improve materials handling? Capacity enhancement means to shorten assembly times for each unit, which can be done in several ways. The report provides three suggestions on how LogMax can place assembly lines (work – cells), roller conveyors for pallets of materials for the assemblers and where pre – assembly can be done. Even their advantages – and disadvantages are described. Methods for improvement are to: (1) introduce of Lean Manufacturing, which reduces, inter alia, time – wasting engines to retrieve details of the inventory, (2) introduction of 5 S in tool cabinets, and (3) introducing Kanban – board, which serves to check and balance the assembly lines. For further assistance with balancing are proposed that LogMax can balance assembly lines using group of mounting. Calculations show that LogMax need to have at least 14 manned workstations per day to achieve the headline goal 2017.

  • 28.
    Kalrot, Mikael
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Studie om hydraulmedietsinverkan på prestanda vid gnistbearbetning2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    EDM is a method that is frequently used in service of nuclear power plants. The method

    is preferred because it causes minimal thermal and force impact on the detail, making it

    suitable to use where resistance to fatigue is of importance. The processing method is

    well proven, but the control of the tool is done via an ungainly hose/cable package

    which is not optimal. One possible step on the way to improving the method is to

    replace the hydraulic fluid, which today consists of de-ionized water and UltraSafe

    glycol mixture, to only consist of de-ionized water. With this new hydraulic fluid, the

    hydraulic part of the hose/cable package could be eliminated (or at least reduced) as

    the pump that supplies the hydraulic pressure to the tool can be moved to the tool. This

    study shows that there are no apparent problems for such development. Material

    removal rate, surface roughness and ease of use, using water as hydraulic fluid are

    comparable with UltraSafe, though other obvious advantages are present, particularly

    such as the environment areas and the workplace environment.

    The report has been commissioned by Westinghouse Electric Sweden AB in Västerås,

    Sweden and will be presented to the commissioner.

  • 29.
    Kalrot, Theres
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Produktutveckling av gripfingrar: för ökad användarvänlighet vid produktionsomställningar2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The degree project has been conducted at Högskolan Dalarna in cooperation with Mora Automation and Robotics AB in Orsa and deals with product development of gripping components for robotic management. The work concerns their range of gripping components, and the goal has been to develop a concept proposal that enhances and simplifies the conversion process with today's gripping segments. Shorter product life expectancy and greater variability spread increasingly demand for flexibility in manufacturing processes. This leads to more frequent changes in production equipment and also the robots found in the production. Adaptation of the robot and its equipment to changes in production must be possible in a simple and reliable way, and the purpose of the report is therefore to investigate the difficulties encountered in the conversion of the robot's gripping device and to propose design changes that could prevent them. Through interviews and observations of the product in use, problem areas in the conversion process have been identified. The biggest challenge can be found in achieving a correct and symmetrical positioning of the gripper fingers on the base jaws. A simple dimensionless grading on the jaws and gripping fingers can provide better adjustment options and lead to significant improvements without the development project being too resource-intensive.

  • 30.
    Kenger, Patrick
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    The way we design: a design process and manual for industrial product development2018In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 20182018, Linköping: The Design Society, 2018Conference paper (Refereed)
    Abstract [en]

    The design work made by designing engineers need to be clearly defined and structured. The design process to follow should naturally lead to a systematic design work that reduce wasteful work, and reuses competence and knowledge from previous design work. The design process should lead to a design work that is made with as little lead-time and cost as possible, yet with a resulting part or product with the right quality. In a time when products become more complex regarding performance, tolerances, material, and with more technological and digital things built into the products, this design process becomes even more important. The Way We Design (TWWD) presented in this paper is one contribution to such a design process for the day-to-day design work. The work behind TWWD is based on both research and industrial practice. The process is built on 11 (A to K) number of checkpoints which gives details on the design work and is customised for the specific company.

     

    Included in TWWD, as addition to the design work itself, are details regarding documentation and templates, standards, and directives. TWWD also include details of the design requirements from other departments within the company, such as sales, purchasing, assembly, manufacturing, painting and service. In this way, the designers can incorporate the requirements from their internal colleges and reduce much of the rework due to misinterpretations or design errors that are detected downstream in the manufacturing process or even at the customers. The TWWD process has been implemented at some companies as their manual for how to perform the design work. The results indicates that it is possible to reduce the design lead-time ranging from 5% to 20%, and with better precision in doing the right things and to reduce wasteful work. The design engineers at a medium and at a large company says that it is the resulting design quality that is the most beneficial from TWWD.

  • 31.
    Kenger, Patrick
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Erixon, Gunnar
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Studies of Design and Assembly Defects on Integrated and Modular Architectures2005In: 15th International Conference on Engineering Design, ICED 05, Melbourne: International Conference on Engineering Design (ICED) , 2005Conference paper (Refereed)
    Abstract [en]

    It is known that despite companies’ efforts to improve the quality of their products, design and assembly defects results in large repair costs both in terms of repair and providing feedback to the origin of the defect. The purpose of this paper is to study these types of defects and the defect rates in design and assembly. The paper presents a web based questionnaire answered by 29 companies. The result shows that the defect rate (defects per product) spanned from 0.01 to 10. Also, design and assembly defects covered 46%, 23% respectively, of all occurred defects. A case study is also presented, performed at a company who recently implemented a modular architecture. In this company, defects from 5 700 integrated product architectures are compared with defects from 431 modular architectures. The average defect rate increased by 21.5% – from 0.65 to 0.79 – when a more modular architecture has been implemented. Furthermore, the study showed that the assembly defects have decreased while the design defects increased. The results presented in this paper will also support the development of the MPV (Module Property Verification) method which is briefly described.

  • 32.
    Kenger, Patrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Beneftis of modularity and module level tests2005In: Emerging solutions for future manufacturing systems, International Federation for Information Processing., 2005, Vol. 159, p. 379-386Conference paper (Refereed)
    Abstract [en]

    Many companies implement a modular architecture to support the need to create more variants with less effort. Although the modular architecture has many benefits, the tests to detect any defects become a major challenge. However, a modular architecture with defined functional elements seems beneficial to test at module level, so called MPV (Module Property Verification). This paper presents studies from 29 companies with the purpose of showing trends in the occurrence of defects and how these can support the MPV.

  • 33.
    Kenger, Patrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering. KTH, Industriell produktion.
    Module property verification: A method to plan and perform quality verifications in modular architectures2006Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Modular product architectures have generated numerous benefits for companies in terms of cost, lead-time and quality. The defined interfaces and the module’s properties decrease the effort to develop new product variants, and provide an opportunity to perform parallel tasks in design, manufacturing and assembly. The background of this thesis is that companies perform verifications (tests, inspections and controls) of products late, when most of the parts have been assembled. This extends the lead-time to delivery and ruins benefits from a modular product architecture; specifically when the verifications are extensive and the frequency of detected defects is high. Due to the number of product variants obtained from the modular product architecture, verifications must handle a wide range of equipment, instructions and goal values to ensure that high quality products can be delivered. As a result, the total benefits from a modular product architecture are difficult to achieve.

    This thesis describes a method for planning and performing verifications within a modular product architecture. The method supports companies by utilizing the defined modules for verifications already at module level, so called MPV (Module Property Verification). With MPV, defects are detected at an earlier point, compared to verification of a complete product, and the number of verifications is decreased.

    The MPV method is built up of three phases. In Phase A, candidate modules are evaluated on the basis of costs and lead-time of the verifications and the repair of defects. An MPV-index is obtained which quantifies the module and indicates if the module should be verified at product level or by MPV. In Phase B, the interface interaction between the modules is evaluated, as well as the distribution of properties among the modules. The purpose is to evaluate the extent to which supplementary verifications at product level is needed. Phase C supports a selection of the final verification strategy. The cost and lead-time for the supplementary verifications are considered together with the results from Phase A and B.

    The MPV method is based on a set of qualitative and quantitative measures and tools which provide an overview and support the achievement of cost and time efficient company specific verifications. A practical application in industry shows how the MPV method can be used, and the subsequent benefits

  • 34.
    Kenger, Patrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Verifiera Modulerna i Produkten: Tidig felelimineringspunkt2004In: Svenskt Monteringsforum, Stockholm, 2004Conference paper (Other academic)
  • 35.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Bergdahl, Anders
    Product verification and defect repair - status and considerations2004In: 2nd International Precision Assembly Seminar, IPAS, Bad Hofgastein, Austria, 2004Conference paper (Refereed)
    Abstract [en]

    Product verifications have become a cost-intensive and time-consuming aspect of modern electronics production, but with the onset of an ever-increasing miniaturisation, these aspects will become even more cumbersome. One may also go as far as to point out that certain precision assembly, such as within the biomedical sector, is legally bound to have 0 defects within production. Since miniaturisation and precision assembly will soon become a part of almost any product, the verifications phases of assembly need to be optimised in both functionality and cost. Another aspect relates to the stability and robustness of processes, a pre-requisite for flexibility. Furthermore, as the re-engineering cycle becomes ever more important, all information gathered within the ongoing process becomes vital. In view of these points, product, or process verification may be assumed to be an important and integral part of precision assembly. In this paper, product verification is defined as the process of determining whether or not the products, at a given phase in the life-cycle, fulfil the established specifications. Since the product is given its final form and function in the assembly, the product verification normally takes place somewhere in the assembly line which is the focus for this paper.

  • 36.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Bergdahl, Anders
    Onori, Mauro
    Modular Product Verifications Based on Design for Assembly2005In: International Forum on Design for Manufacture and Assembly, Providence - Warwick, Rhode Island, USA, 2005Conference paper (Refereed)
    Abstract [en]

    The desire to conquer markets through advanced product design and trendy business strategies are still predominant approaches in industry today. In fact, product development has acquired an ever more central role in the strategic planning of companies, and it has extended its influence to R&D funding levels as well. It is not surprising that many national R&D project frameworks within the EU today are dominated by product development topics, leaving production engineering, robotics, and systems on the sidelines. The reasons may be many but, unfortunately, the link between product development and the production processes they cater for are seldom treated in depth. The issue dealt with in this article relates to how product development is applied in order to attain the required production quality levels a company may desire, as well as how one may counter assembly defects and deviations through quantifiable design approaches. It is recognized that product verifications (tests, inspections, etc.) are necessary, but the application of these tactics often result in lead-time extensions and increased costs. Modular architectures improve this by simplifying the verification of the assembled product at module level. Furthermore, since Design for Assembly (DFA) has shown the possibility to identify defective assemblies, it may be possible to detect potential assembly defects already in the product and module design phase. The intention of this paper is to discuss and describe the link between verifications of modular architectures, defects and design for assembly. The paper is based on literature and case studies; tables and diagrams are included with the intention of increasing understanding of the relation between poor designs, defects and product verifications.

  • 37.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Coda, Mariana
    An approach to evaluate product verifications2004In: IV Internatioal Congress on Mechanical Engineering Technologies, Varna, Bulgaria, 2004Conference paper (Refereed)
    Abstract [en]

    Companies implement a module product assortment as a part of their strategy to, among others, shorten lead-times, increase the product quality and to create more product variants with fever parts. However, the increased number of variants becomes a challenging task for the personnel responsible for the product verifications. By implementing verifications at module level, so called MPV (Module Property Verification) several advantages ensue. The advantages is not only a decrease in cost of verifications, but also a decrease in repair times, occupied space, storages with spare parts, and repair tools. Further, MPV also give an increased product quality due to an increased understanding of which defects that may occur. As an approach to implement MPV, this paper discusses defects and verification processes based on a study at a Swedish company. It also describes a matrix which is used to map relations between company specific cost drivers and so called verification factors. The matrix may indicate cost drivers which have a large impact on the total cost of product verifications.

  • 38.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Erixon, Gunnar
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Lennartsson, S
    Module Property Verification: A Conceptual Framework to Perform Product Verifications at Module level2003In: The 14th International Conference on Engineering Design, Stockholm, 2003Conference paper (Refereed)
  • 39.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Hagström, Lina
    Integrated Product Development in Truck Industry - A Case Study on Product Development Processes2003Report (Other academic)
    Abstract [en]

    This paper presents the result from a case study at Scania on product development processes. The objective with the case study was to gather information on Scania’s product development process (PDP) including the use of CAD and simulation tools, and project work. The objective was also to find any deviations or different interpretations among the employees on the PDP. To gather the information, semi-structured tape-recorded interviews have been used to ensure that individual interpretations from the interviewees could be gathered. Scania uses a defined and structured PDP which facilitates concurrent and cross-functional work. The PDP is implemented and followed to various degrees. The newly employed personnel may have difficulties with communication, both to find and to give information. Although, newly graduated personnel may find it easier to adapt to changes, and also to use a structured process which they have studied at universities. It was also known during the case study that the PDP is a major support for the newly employed personnel, which in turn decreases the time to get into the same working process as the more experienced personnel. Employees with decades of experience know the right sources from which to both give and gather information. Also, the terminology and definitions in the product development process may not be used as intended. This makes it difficult for other project members or teams who need to interpret the information received. At the same time, the routines among the more experienced personnel, which have been set-up throughout the years, make them more inflexible in adapting changes. The findings in the case study as well as challenges with implementing the PDP are known to Scania and are a part of the continuing work with improvement.

  • 40.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Karlsson, Anders
    Human error driving the development of a checklist for foreign material exclusion in the nuclear industry2007In: Human Factors and Ergonomics in Manufacturing, ISSN 1090-8471, E-ISSN 1520-6564, Vol. 17, no 3, p. 283-298Article in journal (Refereed)
    Abstract [en]

    In this article we describe an approach to develop a checklist for foreign material exclusion. Foreign material is material that should not be part of, or supplied with, the product because it can affect the performance of, for example, nuclear fuel rods of nuclear plants. The research itself was initiated by the presence of different types of human errors. Specifically in the nuclear industry, where there is zero tolerance for errors, work to continuously improve safety and quality is of major importance. Our approach should support such work. As a theoretical base, we have considered team errors as well as individual errors. The suggested practical approach is based on foreign materials that originate in or are introduced into a product or a process.

  • 41.
    Kenger, Patrik
    et al.
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Onori, M
    Module Property Analysis in the Assembly Process2003In: Proceedings of the International Precision Assembly Seminar, Bad Hofgastein, Austria, 2003Conference paper (Refereed)
  • 42.
    Lagestam, Mathias
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Process analysis at SSAB South Africa PTY LTD: Pinpointing wastes and reasons for varying lead times2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SSAB South Africa is a 100 % subsidiary to the Swedish company SSAB AB. SSAB South

    Africa works independent with a strict result responsibility and a strict yearly budget. SSAB

    South Africa sells SSAB AB’s products as they are, but they also offers value added services on

    the steel as cutting, grinding, chamfering, and drilling, in order to reach more customers and to

    add value for the customer.

    The purpose of this thesis was to analyze the production process at SSAB South Africa.

    Contributors for held back efficiency and for varying lead times shall be highlighted and

    suggestions for improvement will be given. This in order to contribute to the work with getting a

    more trustworthy and efficient process.

    To achieve the purpose with this thesis, the process has been analyzed in different steps during

    1.5 months. The work began with creating an overview of the whole process, and continued with

    a more detailed analyze of every process.

    The overall conclusion of the process is that it is not robust. Basically what it means is that the

    process is sensitive for changes and variations and many factors affects its full potential. For

    example, it is a lot of unnecessary movement and handling of material and information, which

    can be eliminated and the whole process will work more efficient and trustworthy.

    The thesis successively describes and analyzes the whole process and in the final part of the

    thesis 6 suggestions on how to improve the process at SSAB South Africa, are given.

  • 43.
    Lange, Mark W
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Construction of a Design for Brand Perspective2006In: 1st Nordic Conference on Product Lifecycle Management, NordPLM'06, Gothenburg, Sweden, 2006Conference paper (Refereed)
    Abstract [en]

    The success of a product in its intended market has a clear relation to the strength of its perceived image or brand, which is enabled by an end-user’s perception the product’s sense-able properties. In other words, it is through our perception of a product’s properties that we consider it appealing. Through the application of semiotic sign theories, brand is proposed to be in a relation to the properties of products, where sense-able properties are the objects of design. This paper considers these perceptive properties of a product, where a product serves as an iconical vehicle of brand in opposition to it symbolizing a function. The value of this research result is found in its attempt to derive a perspective of design that integrates product realization from an Engineering position and product association from a Marketing position in a model called Design for Brand.

  • 44.
    Larsen, Lisa
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Hysteres hos cykelergometrar: Problemlösningsstudie baserad på DMAIC och försöksplanering2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The subject of study in this project was a phenomenon that Monark Exercise has had problems with during the development of a new cycle ergometer. The problem is a hysteresis that occurs depending on whether you raise or lower the resistance to a certain level. A test rig for cycle ergometers in the test environment on Dalarna University sports laboratory has been used for experiments to solve the problems.

    The purpose of the study was to understand why the hysteresis exists and how to eliminate or reduce it without affecting the accuracy of the cycle ergometer.

    Through the use of the problem solving method DMAIC and design of experiments, an understanding of the problem and the factors that affect the hysteresis has been built. The results from the study showed that the material in the break belt had the largest impact on the hysteresis. A prototype for a new break belt has been made and the verifying tests showed that it reduced the hysteresis by 80 % without affecting the accuracy of the cycle ergometer. The study also resulted in suggestions for further work to reduce the hysteresis even more as well as to make the cycle ergometer more robust to noise factors.

  • 45.
    Larsson, Olof
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Analys av produktionsbegränsande sektor centrumströläggare2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The company Bergkvist-Insjön owns a major sawmill located in Insjön, Dalarna, Sweden. The manufacturing process consists of refining the softwood timber to finished lumber with the residual products bark, wood chips and sawdust. The logs goes through the production line where each activity is done in a logical order. The sectors containing the machines performing the operations in the production line has been upgraded at different years when there was a need and financial scope to invest. The newest major investment comprises a modern sawing line (2006), which has a higher capacity than the older sawing line. The older sawing line was taken out of service when the new line was introduced. With the production increasing over time, the upgrade has led to previously trouble-free areas have become bottlenecks by the new standards that the new sawing line applies on some type of cuts and timber classes. The sectors that follow the sawing line are affecting the stopping time of great extent and the company has started to focus on making improvements to bottlenecks after the sawing line. The company's own studies have shown that there is potential for improvement in a sector called stick feeding at the center stick stacker. The capacity at the stick feeding is suspected to be low in some types of posts with associated timber classes. The report's main aim consists of investigating if the stick feeding limits the production, and if the production is limited describing the extent to which it occurs. The results of the report indicate that the stick feeding section limits the saw line production and the scale of it is being described. Through the stick feeding, dunnage also passes by up to the dunnage removal process. The flow of dunnage with the dunnage removal process disrupts the supply of sticks which pulls down the stick feeder’s capacity. The company wants to investigate the capacity decrease for the stick feeding due to the flow of dunnage and the dunnage removal process. The report's secondary aim will be to investigate the loss of capacity at the center stick stackers stick feeding sector due to the problems caused by dunnage. The sawing lines current downtime due to lack of capacity at the center stick stacker can be related to the results in this work and lays the foundation for future improvements where different solutions can be developed and compared.

  • 46.
    Larsson, Olof
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Effektiv tillverkning på Hydroforming Design Light: Ett layout förslag2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The company Hydroforming Design Light has got a request for proposal concerning producing a new product in a number of 80 000 units per year. Today the company has a functional layout, which is not optimal for producing high volume – low variation products. This thesis aims to result in a new, more efficient layout. The goal of the new layout is to combine high resource- and flow efficiency. A product oriented layout is proposed instead of today’s functional layout. By placing all of the equipment needed for the production in the same area the distance of transportation is reduced. A quality control before the bottleneck makes sure it’s time is not wasted by processing defective material. A production schedule for high resource- and flow efficiency is proposed. One conclusion in this thesis is that there is more than the layout to create an efficient production.

  • 47.
    Lehtola, Henrik
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Effektivisering av underhåll på central verkstad: En analys av arbetet på UH mek resurs2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stora Enso Kvarnsveden maintenance operations, more specifically, Maintenance mech resource which means the central workshop needs to be streamlined and improved because of the current situation on the paper market with lower prices and demand.The aim of this work is to examine and investigate opportunities to make the group mech resource more competitive.With the help of a situation analysis and the desired position which is presented in the maintenance strategy for Stora Enso Sweden, suggestions for improvements is found with the help of perceived problems. Perceived problems and disorders through conversations and interviews have appeared in the daily work of both supervisors and mechanics of mech resource.Then an analysis of how the daily work appears today compared to the desired position and the perceived problems it has today been made and lastly present proposals for measures and solutions to these perceived problems.

  • 48.
    Leonel, Akoto Chama
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Determination of Thermal and Blue Light Photochemical Hazard Protection needed by Automatic Welding filters2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Recent developments in biological research, has shown that the initial maximum permissible exposure (MPE) limits for protection of workers from risks associated with artificial optical radiations were more stringent than needed. Using the most recent MPE limits for artificial optical radiation this piece of work was focused on the investigation of the level of visible light attenuation needed by automatic welding filters in case of switching failure. Results from the comparison of different exposure standards were employed in investigating the need of Vis/IR and blue light transmittance requirement for automatic welding filters. Real and arbitrary spectra were taken into consideration for the worst and best case scenarios of artificial optical radiations. An excel worksheet developed during the execution of this project took into consideration the exposure from different light sources and the precision of the spectrometer used in measuring the transmittances of a welding filter. The worksheet was developed and tested with known product properties to investigate the validity of its formulation. The conclusion drawn from this project was that attenuation in the light state will be needed for products with the darkest state shade 11 or higher. Also shown is that current welding filter protects the eye well enough even in the case of switching failure.

  • 49.
    Levin, Emil
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Utveckling av tillverkningsmetodik för industriella ljuddämparstavar2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    HIAK is a manufacturer of industrial silencers where the main component is several square silencer bars. In order to produce these silencer bars outside of Hedemora the manufacturing methodology must be updated. Therefore, alternative methods must be found to replace the present methodology and the best way of bending and joining steel sheets for this application are studied.A comparison of different bending and joining methods is made with the specifications available for the silencer bar, along with other limiting factors like material and surroundings. Each method is analysed to bring forth advantages and disadvantages and the most promising methods are presented through several concepts.Some parts of the present bending process are already the most effective solution and should not be replaced unless other changes in design requires it. Other parts of the bending process are not suitable to use other than within the current location in Hedemora because of how specialised the process is. There are however several bending methods available to replace the current specialised process for keeping the functions using a simpler process.Joining methods used today are difficult to replace because of the design of the silencer bar as a result of its needed specifications. Suitable methods to replace todays process are either too sensitive around high temperatures or too sensitive to vibrations. To be able to use a different joining method a change in design is most likely needed.

  • 50.
    Lindgren, Lars-Erik
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Domkin, Konstantin
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Hansson, Sofia
    Dislocations, vacancies and solute diffusion in physical based plasticity model for AISI 316L2008In: Mechanics of materials (Print), ISSN 0167-6636, E-ISSN 1872-7743, Vol. 40, no 11, p. 907-919Article in journal (Refereed)
    Abstract [en]

    A physical based model for the evolution of flow stress of AISI 316L from room temperature up to 1300 °C, strains up to 0.6 and strain rates from 0.0005 up to 10 s-1 is developed. One set of tests have been used for model calibration and another more complex set of tests for its validation. The model is based on a coupled set of evolution equations for dislocation density and (mono) vacancy concentration. Furthermore, it includes the effect of diffusing solutes in order to describe dynamic strain ageing (DSA). The model described the overall flow stress evolution well with exception of the details of the effect of the DSA phenomenon. Its numerical solution is implemented in a format suitable for large-scale finite element simulations.

12 1 - 50 of 79
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