This thesis deals with material parameter estimation for non-linear material models, which is an extremely important part of a finite element analysis. The aim of this work is to both estimate parameters and to quantify the their accuracy. The latter enable a total assessment of how the accuracy at different stages in i.e. the life prediction process affects the final estimated life. Thereby it is also possible to estimate the cost and value of improvements in material data in the different stages of the calculation. The thesis comprises an introductory part and two appended papers. The first paper discusses the influence on parameters and estimated life dependent on the choice of cost-function in the optimisation process. In the second a method for stress integration with regard to transverse recovery is discussed. / Godkänd; 1999; 20070320 (ysko)

This work covers integrated computer-aided applications for design and analysis in particular different integrated design systems for thermal and structural simulations. Two different design systems have been integrated to improve efficiency in product development, i.e. reduced lead-time and higher quality of the product. In the design systems CFD are used as input to FEA and vice versa. The integrated design systems have been demonstrated in two different thermal-structural applications and been evaluated in industrial situations. / <p>Godkänd; 1999; 20070403 (ysko)</p>

Godkänd; 1996; 20080328 (ysko)

The transport industry needs to change. Since the start of industrialism, fossil emissions from vehicles and transport have increased exponentially. Emissions affect both humans, animals and nature. This need to be reduced to stop global warming.This report presents a solution for the transport industry that enables completely environmentally neutral transport and fuel – hydrogen and fuel cells.The project team has examined technical parts of the fuel cell industry to determine how to create such an efficient fuel cell system as possible. The goal of the project is to carry out sustainable integration of fuel cells in a vehicle product that uses batteries as primary energy storage. Today’s consumption and use of lithium-ion batteries will pose future challenges, the group therefore wants to develop a proactive product that results in an extended lifespan and creates benefits by combining two technologies. The report handles the entire development process from idea to finished product with a final part before a market introduction.This result has become a prototype vehicle that is ready for hydrogen operation. An implementation plan has also been developed for how to implement fuel cells and hydrogen in an existing or future electric vehicle. The result is thus a comprehensive solution for how to transition to fully sustainable transport.With a concrete result and sustainable development in focus, the project team has created a product that will show leadership and inspire the transport industry to change and transform towards hydrogen gas energy.

For economic and environmental benefits, sawmills can reduce their waste by sawing with thinner bandsaw blades. When altering the cutting tooth geometry, it is vital to monitor the sawing process in realistic wood conditions such as frozen (green), non-frozen (green) and dried. The fundamental way to monitor the sawing process is to analyse the cutting forces when single cutting teeth interact with the wood. The three cutting forces acting on a sawtooth are the main, normal, and lateral forces. The main force can be split into two: 1) cutting by the main edge and 2) cutting by the side edges (the side force). The objective of this thesis work was to examine the main, side and normal forces in different wood conditions while cutting with different tooth geometries. In sawing, it is desired for the main and side forces to be minimised, and the normal force should remain close to zero. Two abundant Scandinavian wood species were considered: Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in non-frozen, frozen and dried conditions. The heartwood and sapwood were tested separately for non-frozen and frozen wood. The altered tooth geometries were the cutting width, clearance, band thickness, and the radial and tangential clearance angles.The main force was approximately 75% lower for the narrowest cutting tooth of 1.6 mm compared to the reference 2.87 mm wide tooth used in the industry. Narrow cutting teeth could, however, result in faster tool wear and vibrations. The main force was higher in pine than spruce due to the higher density of pine. Frozen sapwood showed distinctly higher main forces. The radial and tangential clearance angles had a negligible effect on the main force. There was a slight reduction in the main force in frozen sapwood at high radial and tangential clearance angles of 6◦. In frozen sapwood, the normal force was highly negative and self-feeding was observed. The normal force was less negative for narrower cutting teeth and at high radial and tangential clearance angles of 6◦. The cutting width, clearance and radial and tangential clearance angles did not have a notable effect on the normal forces in the remaining wood conditions, and the forces remained close to zero. The elastic spring-back plays an important role in side cutting and can be as high as 4 mm. Frozen wood has less elastic spring-back and, therefore, less side cutting. The percentage of side cutting to the main force was between 55% - 75% for dried wood. Lower clearance and lower radial and tangential clearance angles resulted in more side cutting due to increased contact between the teeth and elastic spring-back.The results show that special consideration needs to be taken when sawing frozen sapwood in the winter. Furthermore, the side cutting force plays a larger role when the cutting width is reduced and in dried wood and needs to be studied in more detail to understand its impact on the cutting process better.v

Cibes Lift AB sells personal lifts and currently uses full-scale elevators for demonstration, for example at fairs. Now they want to come up with a mini-elevator that will facilitate the work of demonstrating the Cibes A5000 and also demonstrate the installation of screen walls, which is not possible with the full-scale elevator since the risk of accidents are high and the installation is permanent by pop rivets. In order to facilitate the work, systematic methods were developed to get a clear picture of the course of action, starting with a zero-state analysis of the problem to later immerse ourself in the subject of miniature models using a literature study. Subsequently, interviews and all data from the work were compiled and reviewed with the quality house method to create measurable criteria that could facilitate the draft proposals and the design phase. A risk analysis was also made with regard to constructing a safe product. Once the concepts were completed, one of them was chosen by Cibes. Forthgoing the construction of the elevator was broken down into modules to allow the work to be easily distributed. The result of the work is a construction of a 1:3 scale miniture lift that is capable of demonstrating operation between two floors and display the inner workings of liftsystem propulsions system and installation of a screen wall. The strength of the construction is calculated for the possible impact of a person that the miniature model can be subjected to. And a risk analysis was conducted to facilitate the construction of a safe product. Something that the project would have benefited from is that the zero-state analysis of the design would have been done at an earlier stage to facilitate scheduling and predict any help that might have been needed or knowledge that could be learned before work commenced. / Cibes Lift AB säljer personhissar och använder sig i nuläget av fullskaliga hissar för demonstration vid exempelvis mässor. Nu vill de ta fram en miniatyrhiss som kan underlätta arbetet vid demonstration av Cibes A5000 och även klara av demonstration av installation av skärmväggar vilket inte nu är möjligt med den fullskaliga hissen då skaderisken är stor och installationen är permanent av skärmväggarna med poppnitsförband. För att underlätta arbetet togs systematiska metoder fram för att få en klar bild över arbetets gång vilket började med en nulägesanalys av problemet för att senare fördjupa sig i ämnet miniatyrmodeller med hjälp av en litteraturstudie. Sedan utfördes intervjuer och all data från arbetet sammanställdes och granskades med metoden kvalitetshuset för att skapa mätbara kriterier som kunde underlätta konceptförslagen och konstruktionsfasen även en riskanalys gjordes med hänsyn till att konstruera en säker produkt. När sedan koncepten var klara valdes ett av dem ut av Cibes för att sedan konstruktionen av hissen bröts ner i moduler för att arbetet skulle kunna enkelt fördelas. Resultatet av arbetet är en konstruktion av en miniatyrhiss i skala 1:3 som klarar av demonstration av drift mellan två våningar och visning av draganordningen samt installation av en skärmvägg. Konstruktionens hållfasthet är beräknad för möjlig personpåverkan som miniatyrmodellen kan utsättas för. Och en riskanalys genomfördes för att underlätta konstruktionen av en säker produkt. Något som arbetet skulle ha gynnats av är att den mer grundläggande nulägesanalysen av konstruktionen skulle lagts i ett tidigare skede i arbetet för att underlätta tidsplaneringen och förutspå eventuell hjälp som kunde tänkas behövas eller kunskap som skulle kunna läras in innan arbetet påbörjades.

The world of transport solutions is changing. Scania CV AB (Scania) is trying to drive the shift towards a more sustainable future. One implemented strategy has been to work with gas vehicles, trucks and buses Scania sell trucks that is operating on liquified gas. The fuel is liquified at minus 158 degrees Celsius and the density is between 430-478 Kg/m3 [1]. To determine which tank interface that would be preferable to used in Scania vehicles this master of science thesis was initiated. The scope of the project included both a theoretical as well as a practical methodology to incorporate in the product development process. The stakeholders considered are divided into three groups, production, service and users. The improvement is clear when examining each stakeholder needs where the biggest difference is for production.

In order to meet today’s environmental standards, diesel vehicles must capture the soot and ash emitted from the engine in what is known as a diesel particulate filter (DPF). The continual ash loading of this filter and subsequent exhaust backpressure, increase in fuel consumption, etc. is seen as an unavoidable expense. Replacing the DPF is time consuming and costly, representing significant lost profits to the vehicle owner. However, by reducing the volume of ash in the DPF, the pressure drop and fuel penalty can be curtailed while simultaneously increasing filter life. The thesis paper has presented a study intended to select the ideal method for reducing DPF ash volume in the context of system level integration on a Scania truck. By following an adaptation of the TRIZ method, this work has selected an ideal solution for improving DPF performance. A brief study of two experimental methods for ash volume reduction is presented. From this study, awide-ranging concept generation phase was undertaken to evaluate the ways these methods could be implemented on a vehicle. Through collaboration with industry experts at Scania, a system of criteria was established to select the most promising concept. One concept was chosen for demonstration: water injection into the DPF through a sensor hole in the silencer housing. The proposed injection strategy is such that when the vehicle comes in for scheduled maintenance, this water injection tool can be used to improve vehicle performance and reduce filter changes. In keeping with the criteria and design constraints, this solution eliminates the complication of additional vehicle components, while still effectively reducing ash volume. An initial prototype and subsequent on-vehicle testing is presented which demonstrates that wetting the DPF in this manner is a viable means of reducing ash volume. The result of this test shows that this method can reduce DPF backpressure from ash by 60% after just 3 minutes of water injection. From these results, suggestion for future improvement to the performance and ergonomics of the injection tool is presented.

Additive manufacturing (AM) is acquiring a lot of importance in the manufacturing field. It makes the whole manufacturing process easier and effectively brings down the manufacturing cost compared to the traditional methods. It also provides the manufacturer with the freedom of customization according to each customer. In addition, the implementation of Topology Design Optimization helps in further reduction of costs by reducing the material consumption and energy needed to manufacture the product. In this thesis, products of TylöHelo AB, a leading manufacturer of sauna and steam are studied and optimized. TylöHelo products are manufactured using injection molding methods, in this process, molds are prepared initially, and later molten plastics are shaped using these molds. Molds are expensive and hard to manufacture too. In these types of techniques, the rate of manufacturing is high, but customization is very hard for each new type of design. A new mold has to be printed for each new design. Due to the high cost of mold designing and manufacturing, customization is very rarely seen. In this thesis, a certain product of TylöHelo sauna assembly is selected and redesigned using Topology Optimization to achieve both reduced manufacturing cost and good mechanical properties without compromising on the functional behavior. Solid mechanics simulation is performed to assess the mechanical properties of the part optimized and is compared to the original part. Furthermore, Fused Deposition Modeling (FDM), an extrusion-based AM, is used for fabricating the part and then implemented in the assembly of the sauna room. Finally, a detailed cost analysis is presented to provide an estimation of savings incurred for the company. This thesis identified two new topology optimized design based on manual methods and using the software. The results show that the new designs had nearly 58 to 67% cost reduction compared to the original 3D printed design and 64-69% reduction in mass of the product. This also means that the 3D printed topology optimized part can match the prices set by the injection molding. However, the 3D printed part quality and high-volume production can still be a challenge. This thesis also provides a guideline for the redesign manufactures, trying to incorporate Additive manufacturing in their production line.

Purpose – The purpose of the study is to investigate how a deviation process can be streamlined and integrated into a manufacturing company’s daily work. Two questions have been created to answer the purpose: How should defective products be handled effectively? How can the deviation process become a natural part of the daily work?   Method – The study is formed as a single case study from the case company’s problem. Different methods for data collection have been used, such as; literature review, interviews, observations, document studies and a comparison to another manufacturing company. An understanding of the problem area has been reached through the literature review. Five people with different work roles at the case company were interviewed with the aim to understand the communication picture, obtain a complete image of the daily work and its challenges. Observation has been performed on two occasions, in order to gain insight into the work steps covered by the deviation management. Document studies have been used to create empirical data. Finally, a comparison with another producing company has been drawn out with the intention of gaining insight into how the deviation management is designed in another company.   Findings – In order to achieve a more efficient handling of deviations at the case company, three main problems have been identified. The first problem is communication, which includes the lack of a common reporting system, resource shortage, communication between management and employees, as well as between departments. The communication can be improved by implementing a new reporting system, assign an extra employee for the deviation handling and through an increased understanding from the management about the employee’s needs. The second problem is standardized work that deals with the lack of a common working method and work steps for handling deviations. A standardized working method in which both defects and misunderstandings are reduced can be achieved through a systematically designed storage shelf and a new flow chart, which has been developed. The third problem is education that involves difficulties in assessing and reporting defective material. In order to reduce uncertainty about the assessment and reporting of defects in production and to release time for other departments, increased training for employees is required.   Implications – The study has drawn attention to a lack of existing theory regarding deviation management. It has been noted that the root cause of the problem is due to more reasons than assumed from the beginning and thus new knowledge has been developed. Companies with similar problems as the case company can apply some of the study's suggestions for action.   Limitations – The limitations that are found in the study include confidentiality where the case company has chosen not to be named by the company name and not to disclose certain information. Since the study is a single case study, the generalisability is limited to a certain extent.   Keywords – Internal deviation handling, Deviation handling, Defects, Waste, Standardized work, Reporting system, Communication. / Syfte – Studiens avsikt är att undersöka hur en avvikelseprocess kan effektiviseras och integreras i daglig drift hos ett producerande företag. Två frågeställningar har skapats för att besvara syftet: Hur bör defekta produkter hanteras på ett effektivt sätt? Hur kan avvikelseprocessen bli en naturlig del i det dagliga arbetet?   Metod – Studien är en enfallsdesign utformad efter fallföretagets problem. Olika datainsamlingsmetoder har använts i form av litteraturstudie, intervjuer, observationer, dokumentstudier samt jämförelse med ett annat företag. En förståelse skapades kring problemområdet med hjälp av litteraturstudie. Fem personer med olika arbetsroller inom fallföretaget intervjuades för att förstå kommunikationsbilden, få en komplett bild av det dagliga arbetet och dess utmaningar. Observation har utförts under två tillfällen. Detta för att få insikt kring arbetsstegen som avvikelsehanteringen omfattar. För att skapa empiriskt underlag har dokumentstudier använts. Slutligen har en jämförelse med ett annat producerande företag genomförts med avsikt att få en inblick i hur hanteringen kan se ut hos ett annat företag.   Resultat – För att uppnå en effektivare avvikelsehantering har tre huvudsakliga problem identifierats. Det första problemet är kommunikation vilket innefattar avsaknaden av ett gemensamt rapporteringssystem, resursbrist, kommunikation mellan ledning och anställda samt mellan avdelningar. Kommunikationen kan främjas genom ett nytt rapporteringssystem, en extra resurs avsatt för avvikelsehanteringen samt en ökad förståelse från ledningen kring de anställdas behov. Det andra problemet är standardiserat arbete som handlar om avsaknaden av ett gemensamt arbetssätt och arbetssteg för hantering av avvikelser. Ett standardiserat arbetssätt där både defekter och missförstånd reduceras kan uppnås genom en systematiskt utformad lagerhylla samt ett nytt flödesschema, vilket tagits fram. Det tredje problemet är utbildning som omfattar svårigheter kring bedömning och rapportering av defekt material. För att minska osäkerhet kring bedömning och rapportering av defekter i produktion samt att frigöra tid för andra avdelningar krävs utökad utbildning för anställda.   Implikationer – Studien har uppmärksammat en brist av existerande teori kring avvikelsehantering. Det har uppmärksammats att grundproblemet beror på fler orsaker än vad som antogs från början och därmed har ny kunskap framtagits. Företag med likande problem som fallföretaget kan applicera en del av studiens åtgärdsförslag.   Begränsningar – Studiens begränsningar innefattar sekretess där fallföretaget valt att inte nämnas vid namn samt att inte offentliggöra viss information. Eftersom studien är en enfallsdesign begränsas generaliserbarheten till en viss del.   Nyckelord – Intern avvikelse, Avvikelsehantering, Defekter, Slöseri, Standardiserat arbete, Rapporteringssystem, Kommunikation.