This report is a Bachelor thesis executed at Jönköping University during the spring of 2017 by Jenny Larsson and Molly Sandbacka. The thesis was conducted as a final part of the education program for the Degree of Bachelor of Science in Mechanical Engineering, specialisation Product Design and Development. The most dangerous and physically demanding work assignment allowed in Sweden is to work as a firefighter. The firefighters carries oxygen cylinders on their backs and from there the oxygen is transported to a breathing mask and to a pressure gauge. The pressure gauge indicates how much oxygen is left and gives the firefighters an idea over ​​how long they can work. More features could be applied on the device if it were to be digitalised. A digitalisation laid the foundation of the Bachelor thesis performed on behalf of the technical consulting company Combitech in Jönköping. The aim with this project was, from problem to prototype, to construct a component within a pressure gauge. The component shall distribute the oxygen from the cylinders to partly an analogue gauge and partly a digital pressure sensor. Another section of the project was to choose material and suggest how the device should remain tight. Based on theories of the product development process different methods has been used to deliver two concept proposals with different advantages regarding function, manufacturing and cost. One concept has a freely rotating system that promotes the function, while the other concept is easier to manufacture and thus a cheaper alternative. The project has also resulted in three recommended metals: low alloy steel, medium carbon steel and brass quality already used on one of the components of the pressure gauge. The concepts and materials are presented and analysed by simulations, prototypes, risk analysis and value analysis. The results of the Bachelor thesis have contributed with a component so the equipment of the firefighter can be modernised through a lighter, more flexible and digitalised pressure gauge. Furthermore, the other components of the pressure gauge and the full device need to be tested to check that the specifications are met. / Denna rapport behandlar det examensarbete som utförts vid Jönköping University under vårterminen 2017 av Jenny Larsson och Molly Sandbacka. Examensarbetet genomfördes som en avslutande del av utbildningen till högskoleingenjör och teknologie kandidat inom Maskinteknik produktutveckling och design. Att arbeta som rökdykare är en av de allra farligaste och fysiskt mest krävande arbetsuppgifter som tillåts i Sverige. På ryggen bär rökdykare en eller två syrgastuber och därifrån transporteras syret till en andningsmask och till en tryckmätare. Denna mätare indikerar hur mycket syrgas som finns kvar och ger då rökdykaren en uppfattning över hur länge rökdykaren kan arbeta. Digitalisering av denna mätare skulle medföra att fler funktioner skulle kunna appliceras. Detta lade grunden för examensarbetet som genomfördes på uppdrag av teknikkonstultbolaget Combitech i Jönköping. Syftet var att konstruera, från problem till prototyp, en komponent som ska förgrena syrgas till dels en analog manometer, dels en digital trycksensor inuti en tryckmätare. Examensarbetet skulle även innefatta materialval och förslag kring hur mätaren ska förbli tät. Genom metoder utifrån teorier om produktutvecklingsprocessen har arbetet resulterat i två konceptförslag med olika fördelar gällande funktion, tillverkning och kostnad. Det ena konceptet har en inbyggd svivelfunktion vilken främjar funktionen, medan det andra konceptet är enklare att tillverka och därmed ett billigare alternativ. Arbetet har även resulterat i tre på lufttrycksförgreningen applicerbara metaller: låglegerat stål, medium kolstål och en mässingskvalité som redan används på en av delkomponenterna i tryckmätaren. De båda koncepten samt materialen presenteras och analyseras genom simuleringar, prototyper, riskanalys och värdeanalys. Examensarbetets resultat har bidragit med en komponent så att rökdykarens utrustning kan moderniseras genom en smidigare, lättare och digitaliserad tryckmätare. Vidare behöver tryckmätarens övriga komponenter och den fulla enheten testas för att kontrollera så att kravspecifikationen uppfylls.

This master thesis treats the development of a new component in a tidal energy power plant. The technology that the component should be used in extracts energy from tidal an low velocity currents. This is done by that a turbine is placed on a kite which is pushed forward in the water due to the lifting force acting on the wing. A tether connects the kite with a bottom joint that is placed on a foundation at the seabed. The bottom joint used today is heavy and expensive, which was the main reason to that this thesis was initiated. In this work, the possibility of using a polymer based design for the connection between the tether and foundation was investigated. The optimal outcome of the project was that the polymer solution should provide a spring function to the power plant. A lot of conventional product development methods have been used in the project. The project was divided into five parts: planning, product specification, concept generation, concept choice and conceptual design. In order to understand what was required of the solution in terms of the spring function, a model that aimed to represent what effect a spring function would have on the power plant was developed. According to the model, a spring function in the tether direction could increase the velocity of the kite in its trajectory. The model is based on some simplifications which is assessed to need further investigation. The spring function was translated to that the component should be able to elongate as a response to the force acting in the tether direction. In the concept choice phase it was chosen to proceed with a design similar to that of a bend stiffener. It was decided that a spring function was not required of the component, though desirable. A material selection was performed and the most optimal material for a single part that should be able withstand the tension, allow rotation, and provide a spring function was concluded to be TPU(ester, aromatic, Shore 50D). In the attempt to understand what was needed to be considered if the spring function should be solved by a material response in a polymer component, relevant theory was collected. A numerical analysis in Abaqus was performed which indicated that such a solution was unreasonable. It was then decided to proceed with the development of a bend stiffener, where the tether should be connected directly to the foundation. The thesis finally concludes with a conceptual design of a bend stiffener. The most suitable material for a bend stiffener was concluded to be TPU(ether, aliphatic, Shore 60D). The initial dimensions were determined by the maximum angle and tension combination that the tether would be exposed to. A static analysis was performed in Abaqus to illustrate the function of the product. The analysis indicated that a bend stiffener could provide the required function. However, the stress in the component became high, which indicated that the bend stiffener material might fail due to the applied load. In order to fully evaluate this, it was concluded that a more accurate material model was required.

Sustainability within automotive industry has been an important topic that is covered in several studies. Due to the multi-aspect nature of sustainability and the variety of the factors need to be taken in consideration when choosing a material, the decision-making process could be challenging. This study focuses on lubricants within the automotive industry and proposes a framework consisted of three milestones that aspire to assist automotive manufacturers in sustainable lubricant selection. The study uses LCA as an environmental assessment tool for fully formulated lubricants and multicriteria decision matrix to include other criteria indicators in the decision-making process quantitively. The study also contributes to the literature by performing LCA for fully formulated lubricants. The framework was applied on well-established case company within the automotive industry (Volvo Cars Corporation) in Sweden. The results showthe importance and significant impacts of the inclusion of the additives in LCA studies done on lubricants using CV joint grease as a case study. It also shows the effect of the organisational preferences on the final results of the framework.

Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. This may be achieved through the use of compliant corrugations. An innovative padding concept is investigated for such applications. Also, recent attention given to the potential for using origami in engineering applications may provide new corrugation configurations that are advantageous for energy absorption and force distribution. This work explores three areas related to these concepts.First, the parameters of a compliant, corrugated padding concept are investigated using Finite Element Analyses (FEA) and physical testing. The shape of the corrugation cross section is explored as well as the wavelength and amplitude by employing a full factorial design of experiments. FEA results are used to choose designs for prototyping and physical testing. The results of the physical testing were consistent with the FEA predictions although the FEA tended to underestimate the peak pressure compared to the physical tests. A performance metric is proposed to compare different padding configurations. The concept shows promise for sports padding applications. It may allow for designs which are smaller, more lightweight, and move better with an athlete than current technologies yet still provide the necessary protective functions.Second, the elastic energy absorbing properties of a particular origami folding pattern, the Miura-ori, is investigated. Analytical models for the kinematics and force-deflection of a unit cell based on two different modes of elastic energy absorption are derived. The models are used to explore the effects of the key geometrical parameters of the tessellation. Physical prototypes are compared to the analytical models.Third, a three-stage strategy is presented for selecting materials for origami-inspired corrugations that can deform to achieve a desired motion without yielding, absorb elastic strain energy, and be light weight or cost effective. Two material indices are derived to meet these requirements based on compliant mechanism theory. Using Finite element analysis, it is shown that the properties of Miura-ori pattern has advantages for energy absorption and force distribution when compared to a triangular wave corrugation. While the focus of these studies is the Miura-ori tessellation, the methods developed can be applied to other tessellated patterns used in energy absorbing or force distribution applications.

The mechanical properties of a 2D material can be altered with Kirigami, a Japanese paper cutting art. Such altered materials are called metamaterials – where a certain geometry is imposed on a material to change its material properties.This thesis documents the effects of a specific Kirigami pattern cut into a range of different 2D materials, such as plastic films or paper – the results of which will be used to evaluate the suitability of each material candidate to a product, the ‘IV strip’, designed and produced by Ortrud Medical AB.The strip contains a patterned ‘spring’ area, which has reduced stiffness due to the patterned defects imposed on it, and a force indication zone. The force indication zone will not be considered.The material selection study used a Pugh’s Evaluation matrix method to choose the best candidate. A few materials were chosen due their suitability in criteria such as robustness of results, tearing force and patient comfort. One material was selected for further experimentation due to its interesting stress/strain characteristics.A further study was then carried out to assess the possibility of tuning the pattern dimensions to alter the tensile properties of the metamaterial. This study includes both computational and experimental methods to verify the feasibility of a simulation model. The study found that it is possible to draw relationships between cut length and stiffness of the pattern. Whilst the computational and experimental results were similar for very small deformations, the FEM simulation struggles at higher deformations because of the lack of available material properties for the program input. / De mekaniska egenskaperna hos ett tvådimensionellt material kan ändras med hjälp av Kirigami, som är en japansk klippkonst i papper. Material där man med geometriförändringar ändrar materialegenskaperna kallas metamaterial. I det här examensarbetet dokumenteras inverkan av ett Kirigami-mönster i olika material, bland annat plast och papper. Resultaten kommer att användas för att utvärdera om något passar att användas till ett stasband framtaget av Ortrud Medical AB. Remsan har en mönstrad ”fjäderyta”, som påverkar styvheten, och en kraftzoon. I det här arbetet studeras enbart det mönstrade området. För att utvärdera materialen och välja det mest lämpade, användes Pughs utvärderingsmatris. Materialen utvärderas bland annat med avseende på robusthet, dragmotstånd och patientkomfort. Ett av materialen valdes ut för ytterligare provning på grund av dess intressanta deformationsbeteende.I det här arbetet tillämpas både experimentella och analytiska metoder. Resultaten användes sedan för att verifiera en FE-modell av systemet. Modellen och experimenten gav liknade resultat vid små deformationer, dock begränsades verifieringen av materialdatabasen. En delstudie visade att det är möjlighet att ställa in mönsterdimensionerna, så att töjningsegenskaperna hos metamaterialet kan justeras.

De mekaniska egenskaperna hos ett tvådimensionellt material kan ändras med hjälp av Kirigami, som är en japansk klippkonst i papper. Material där man med geometriförändringar ändrar materialegenskaperna kallas metamaterial. I det här examensarbetet dokumenteras inverkan av ett Kirigami-mönster i olika material, bland annat plast och papper. Resultaten kommer att användas för att utvärdera om något passar att användas till ett stasband framtaget av Ortrud Medical AB. Remsan har en mönstrad ”fjäderyta”, som påverkar styvheten, och en kraftzoon. I det här arbetet studeras enbart det mönstrade området. För att utvärdera materialen och välja det mest lämpade, användes Pughs utvärderingsmatris. Materialen utvärderas bland annat med avseende på robusthet, dragmotstånd och patientkomfort. Ett av materialen valdes ut för ytterligare provning på grund av dess intressanta deformationsbeteende. I det här arbetet tillämpas både experimentella och analytiska metoder. Resultaten användes sedan för att verifiera en FE-modell av systemet. Modellen och experimenten gav liknade resultat vid små deformationer, dock begränsades verifieringen av materialdatabasen. En delstudie visade att det är möjlighet att ställa in mönsterdimensionerna, så att töjningsegenskaperna hos metamaterialet kan justeras. / The mechanical properties of a 2D material can be altered with Kirigami, a Japanese paper cutting art. Such altered materials are called metamaterials – where a certain geometry is imposed on a material to change its material properties.  This thesis documents the effects of a specific Kirigami pattern cut into a range of different 2D materials, such as plastic films or paper – the results of which will be used to evaluate the suitability of each material candidate to a product, the ‘IV strip’, designed and produced by Ortrud Medical AB.  The strip contains a patterned ‘spring’ area, which has reduced stiffness due to the patterned defects imposed on it, and a force indication zone. The force indication zone will not be considered. The material selection study used a Pugh’s Evaluation matrix method to choose the best candidate. A few materials were chosen due their suitability in criteria such as robustness of results, tearing force and patient comfort. One material was selected for further experimentation due to its interesting stress/strain characteristics. A further study was then carried out to assess the possibility of tuning the pattern dimensions to alter the tensile properties of the metamaterial. This study includes both computational and experimental methods to verify the feasibility of a simulation model. The study found that it is possible to draw relationships between cut length and stiffness of the pattern. Whilst the computational and experimental results were similar for very small deformations, the FEM simulation struggles at higher deformations because of the lack of available material properties for the program input.

No description available.

Detta examensarbete fokuserar på att minska vikten på en undervattens rengöringsrobot (bottensug) som kallas W50. För närvarande väger den ungefär 28 kg, och vårt mål är att reducera vikten till strax under 20 kg. Om det primära målet inte uppnås, kommer detta arbete att presentera alternativa förslag eller koncept som kan underlätta för WEDA AB att fortsätta sin strävan efter en lättare och mer effektiv bottensug. Genom en kombination av konstruktionsanalys, materialval och marknadsundersökningar av andra möjliga tillverkare undersöker vi olika möjligheter att minska vikten utan att kompromissa med prestanda och funktionalitet så mycket. Resultatet och förslagen från detta arbete kommer att bidra till att optimera W50:s totala vikt, samtidigt som den fortsätter att vara kraftfull och effektiv jämfört med sina konkurrenter. Produktutveckling och produktframtagning har varit ett lyckat försök, nya komponenter har tagits fram och befintliga produkter har utvecklats med nya material eller omkonstrueras. / This thesis focuses on reducing the weight of an underwater cleaning robot (bottom suction) called W50. Currently it weighs approximately 28g, and our goal is to reduce the weight to just under 20 kg. If the primary goal is not achieved, this work will present alternative proposals or concepts that can make it easier for Weda AB to continue its quest for a lighter and more efficient bottom suction. Through a combination of design analysis material selection and market research of other possible manufacturers, we investigate various possibilities to reduce weight without compromising performance and functionality as much. The results and suggestions from this work will help to optimize the overall weight of the W50, while continuing to be powerful and efficient compared to its competitors. Product Development has been a successful attempt, new components have been developed and existing products have been developed with new materials or redesigned.

Material selection is one of the major points that should be taken into account seriously in the engineering design stage. Each material has various properties such as mechanical, thermal, electrical, physical, environmental, optical and biological properties. However, it is a well known fact that only a limited number of design engineers have a thorough knowledge on all these properties of a specific material, which is planned to be used in the manufacturing of the product. Therefore, the design engineer should be guided in selecting the most suitable material. In the scope of this thesis, the aim was to develop an algorithm and a software package for material selection to help the design engineer in his decision making process. In the program, since steel is a widely used material in industry, it was selected as a material class among whole engineering materials, and a database covering all the necessary properties of various steels was constructed. These properties include chemical, mechanical, thermal, electrical and physical properties for steels. The database developed by using Microsoft Access also contains steels of 29 different steel standards and can be updated if the user wants. The software package was developed for Windows environment by using Microsoft Visual Basic 6.0. In the program, steels can be searched for the list of suitable steels by entering application areas and properties such as chemical component, yield strength, heat capacity and electrical resistance. In addition to this, lists of steels can be created by selecting the appropriate name of the steel standards. Force and load calculations for various deformation processes such as forging, rolling, extrusion and drawing can also be carried out in the relevant modules within the program.

abstract: The focus of this research is to investigate methods for material substitution for the purpose of re-engineering legacy systems that involves incomplete information about form, fit and function of replacement parts. The primary motive is to extract as much useful information about a failed legacy part as possible and use fuzzy logic rules for identifying the unknown parameter values. Machine elements can fail by any number of failure modes but the most probable failure modes based on the service condition are considered critical failure modes. Three main parameters are of key interest in identifying the critical failure mode of the part. Critical failure modes are then directly mapped to material properties. Target material property values are calculated from material property values obtained from the originally used material and from the design goals. The material database is searched for new candidate materials that satisfy the goals and constraints in manufacturing and raw stock availability. Uncertainty in the extracted data is modeled using fuzzy logic. Fuzzy member functions model the imprecise nature of data in each available parameter and rule sets characterize the imprecise dependencies between the parameters and makes decisions in identifying the unknown parameter value based on the incompleteness. A final confidence level for each material in a pool of candidate material is a direct indication of uncertainty. All the candidates satisfy the goals and constraints to varying degrees and the final selection is left to the designer's discretion. The process is automated by software that inputs incomplete data; uses fuzzy logic to extract more information and queries the material database with a constrained search for finding candidate alternatives. / Dissertation/Thesis / Collection of Images used in Thesis / M.S. Mechanical Engineering 2011