This master’s thesis is the continuation of a preliminary study conducted in the fall of 2011. The project is defined by NTNU in cooperation with Laerdal Medical. Laerdal Medical AS is a major manufacturer of medical equipment and training products based in Stavanger, Norway. They now want to make an addition to their spinal product line and offer a lower cost, but quality alternative to their existing spineboard (the BaXstrap spineboard).A spineboard is a long, flat and rigid board mainly used for the immobilization and transportation of trauma patients with suspected spinal injuries.As a basis for comparison of stiffness of the old and proposed new alternative, phys- ical tests of the BaXstrap spineboard were conducted.The new spineboard concept proposes a transition from the current rotational molding process of the BaXstrap to injection molding the new spineboard in two parts and joining them by hot plate welding.Through a part breakdown approach to the spineboard, constraint and possibilities for all design features of the spineboard were reviewed. This was based on extensive re- search through current literature, standards, competitor reviews, discussions with Laerdal and user interviews. From two final design concepts, a curved and tapered spineboard with features continued from the BaXstrap was chosen and another design iteration was performed.The results of this project has, in addition to en extensive product specification, been a CAD model, CAE analysis and a physical foam mock-up of the final design iteration of the proposed new spineboard. CAE analysis showed that the new spineboard can have better resistance to torsion and bending than the BaXstrap.Descriptions of the CAD model structures and how to prepare mesh and load cases for CAE analysis of the spineboard will be used as a basis for further development of the spineboard at Laerdal Medical.

<p>Micro Electro Mechanical Systems (MEMS) produced to date include IR detectors, accelerometers, pressure sensors, micro lenses, actuators, chemical sensors, gear drives, RF devices, optical processor chips, micro robots and devices for biomedical analysis. The track for tomorrow has already been set and products like 3D TV, physician on a chip, lab on a chip, micro aircraft and food safety sensors will be developed when the technology matures and the market is ready.</p><p>Todays MEMS fabrication is typically based around a silicon substrate and borrow batch fabrication processes from the IC industry. Many of the developed MEMS products have never left a laboratory environment because they are fragile in the macro environment. The way to deal with this is to provide proper packaging so that they can be handled. This poses one of the major challenges in the MEMS industry. Not many packaging techniques have been commercially developed for MEMS and companies that have overcome the packaging problems very seldom reveal their packaging techniques. Functional problems that could be associated with a MEMS structure are often amplified by the package. The reason for this is often associated with packaging stress. Packaging stress related problems is what has kept many promising products from emerging on the market. Even the commercially available pressure sensors and accelerometers have packaging stress problems, but most of them have been overcome. A first step towards solving these challenges is to localise, quantify and understand the critical packaging stresses that act in a packaged MEMS device.</p><p>The goal of this work was to understand how packaging stresses act in a plastic moulded MEMS chip. The work has been threefold; simulation of transfer moulding, static stress analysis of the plastic capsule after moulding and modelling of the piezo-resistive behaviour of a MEMS pressure sensor.</p><p>This dissertation is divided into 9 chapters. Chapter 1 introduces the concept of level-0 and level-1 packaging and looks at different techniques of obtaining the different packaging levels. It introduces the Small Outline Package (SOP) which is the package that has been simulated in this dissertation.</p><p>Chapter 2 gives the background in the theory that has been used to complete this work. It starts by discussing the chemistry and mechanics of thermosetting polymers. Then the rheological behaviour of Epoxy Moulding Compounds (EMC) in a transfer moulding process is discussed. </p><p>The experimental results from the thermomechanical material characterisation of the EMC are presented in Chapter 3. The material was found to have a Tg of 130^oC and coefficient of linear expansion of /oC and /oC below and above Tg respectively. It was further found that the material showed linear viscoelastic behaviour. Stress relaxation tests were run to obtain the relaxation coefficients needed for accurate modelling. The material was found to behave in a thermo rheologically simple manner and the WLF shift function was used to describe the time-temperature superposition principle.</p><p>Chapter 4 addresses the applicability of the plastic processing simulation code, C-Mold, for simulations of MEMS packaging in a SOP. It was found that the 2.5D simulation technique used by the software was inadequate for simulating the polymer filling of the SOP in question. This conclusion was drawn because 3D flow effect were observed in the moulding cavities. The cause for the 3D flow effect was the height of the SOP which was relatively large in order to accommodate for the MEMS device. However, the software proved to be very useful for balancing the runner system.</p><p>Chapter 5 starts with the development of a novel method for calculating the accurate piezoresistance for implanted silicon piezo-resistors. The method let each finite element in a piezoresistor region represent one resistor in a resistor network. The total resistance was then found by simple resistor summation. This method was then utilized on a silicon diaphragm pressure sensor, which had four piezo-resistors implanted into the top surface. The resistors on the diaphragm formed a Wheatstone bridge and the change in piezo-resistance, as a result of applied pressure and hence change in the stress field, was transformed into an electrical signal by proper post processing. The model was built from the design specifications of a commercially manufactured die. The results were compared to the production measurements and matched the data within one standard deviation. It was found that the level-0 package had an effect on the output signal. This work is believed to be the first to report an estimation of the distortion effect that a level-0 package has on a sensor signal with temperature.</p><p>Chapter 6 presents the model of the complete MEMS pressure sensor component encapsulated by EMC in a SOP. The EMC was treated as being elastic and temperature dependent. The method that was developed and calibrated in Chapter 5 was used as an indirect measure of the accuracy of the FEM model. It was evident that the package had a profound effect on the sensor signal. This was consistent with the actual measured data. The match of the signal data was not satisfactory. The signal values for two of the four service temperatures lay outside 3 standard deviations of the experimentally measured results. The estimated sensitivity of the die also fell outside 3 standard deviations for three of the four service temperatures.</p><p>A special vector plot was developed to understand how the pressure, or packaging stress, from the EMC effected the signal and sensitivity of the sensor die. The numerical simulations were done assuming a stress free temperature of 175^oC, the moulding temperature. The packaging stress was found to increase with decreasing temperature. This was the effect of the subsequent increase in ΔT as the service temperature decreased.</p><p>The signal at zero pressure was found to shift as a function of temperature. This was caused by the packaging stress and a corresponding stress-field-shift on the diaphragm. The origin for this shift was an uneven packaging stress between the front and the back side of the sensor die. At -7^oC, the pressure on the front and the back was 30 and 20MPa respectively. This caused an uneven bending moment on the membrane long sides and resulted in a shift in the stress field.</p><p>Chapter 7 elaborated the model one step further by treating the EMC as a viscoelastic material. The result of using the viscoelastic material model showed a reduction in the packaging stress due to stress relaxation. Viscoelastic materials are temperature and strain-history dependent. It was therefore necessary to run the model through the same processes posed by the manufacturing of the MEMS and SOPs. These included a set of thermocycles between -40^oC and 125^oC before the signals as a function of temperature and pressure were taken. The thermocycles were found to have a positive effect on signal shifting. Less signal distortion was seen with more cycles. The estimated and measured signal- vs. temperature-values matched within two standard deviations. The estimated sensitivities did not match the experimental measurements any better than those obtained for the elastic case. It was also found that sensitivity was nearly independent on packaging stress, but significantly dependent on pressure loading conditions.</p><p>The use of the viscoelastic model gave an improvement in simulated signal accuracy over the elastic model. It became clear that the EMC had to be treated as a viscoelastic material.</p><p>Chapter 8 concerned the change in material properties of the EMC and the impact this had on the FEM results. It was found that the behaviour of the MEMS pressure sensor was greatly affected by such changes.</p><p>Chapter 9 present the concluding remarks of this study.</p>

Micro Electro Mechanical Systems (MEMS) produced to date include IR detectors, accelerometers, pressure sensors, micro lenses, actuators, chemical sensors, gear drives, RF devices, optical processor chips, micro robots and devices for biomedical analysis. The track for tomorrow has already been set and products like 3D TV, physician on a chip, lab on a chip, micro aircraft and food safety sensors will be developed when the technology matures and the market is ready. Todays MEMS fabrication is typically based around a silicon substrate and borrow batch fabrication processes from the IC industry. Many of the developed MEMS products have never left a laboratory environment because they are fragile in the macro environment. The way to deal with this is to provide proper packaging so that they can be handled. This poses one of the major challenges in the MEMS industry. Not many packaging techniques have been commercially developed for MEMS and companies that have overcome the packaging problems very seldom reveal their packaging techniques. Functional problems that could be associated with a MEMS structure are often amplified by the package. The reason for this is often associated with packaging stress. Packaging stress related problems is what has kept many promising products from emerging on the market. Even the commercially available pressure sensors and accelerometers have packaging stress problems, but most of them have been overcome. A first step towards solving these challenges is to localise, quantify and understand the critical packaging stresses that act in a packaged MEMS device. The goal of this work was to understand how packaging stresses act in a plastic moulded MEMS chip. The work has been threefold; simulation of transfer moulding, static stress analysis of the plastic capsule after moulding and modelling of the piezo-resistive behaviour of a MEMS pressure sensor. This dissertation is divided into 9 chapters. Chapter 1 introduces the concept of level-0 and level-1 packaging and looks at different techniques of obtaining the different packaging levels. It introduces the Small Outline Package (SOP) which is the package that has been simulated in this dissertation. Chapter 2 gives the background in the theory that has been used to complete this work. It starts by discussing the chemistry and mechanics of thermosetting polymers. Then the rheological behaviour of Epoxy Moulding Compounds (EMC) in a transfer moulding process is discussed. The experimental results from the thermomechanical material characterisation of the EMC are presented in Chapter 3. The material was found to have a Tg of 130oC and coefficient of linear expansion of /oC and /oC below and above Tg respectively. It was further found that the material showed linear viscoelastic behaviour. Stress relaxation tests were run to obtain the relaxation coefficients needed for accurate modelling. The material was found to behave in a thermo rheologically simple manner and the WLF shift function was used to describe the time-temperature superposition principle. Chapter 4 addresses the applicability of the plastic processing simulation code, C-Mold, for simulations of MEMS packaging in a SOP. It was found that the 2.5D simulation technique used by the software was inadequate for simulating the polymer filling of the SOP in question. This conclusion was drawn because 3D flow effect were observed in the moulding cavities. The cause for the 3D flow effect was the height of the SOP which was relatively large in order to accommodate for the MEMS device. However, the software proved to be very useful for balancing the runner system. Chapter 5 starts with the development of a novel method for calculating the accurate piezoresistance for implanted silicon piezo-resistors. The method let each finite element in a piezoresistor region represent one resistor in a resistor network. The total resistance was then found by simple resistor summation. This method was then utilized on a silicon diaphragm pressure sensor, which had four piezo-resistors implanted into the top surface. The resistors on the diaphragm formed a Wheatstone bridge and the change in piezo-resistance, as a result of applied pressure and hence change in the stress field, was transformed into an electrical signal by proper post processing. The model was built from the design specifications of a commercially manufactured die. The results were compared to the production measurements and matched the data within one standard deviation. It was found that the level-0 package had an effect on the output signal. This work is believed to be the first to report an estimation of the distortion effect that a level-0 package has on a sensor signal with temperature. Chapter 6 presents the model of the complete MEMS pressure sensor component encapsulated by EMC in a SOP. The EMC was treated as being elastic and temperature dependent. The method that was developed and calibrated in Chapter 5 was used as an indirect measure of the accuracy of the FEM model. It was evident that the package had a profound effect on the sensor signal. This was consistent with the actual measured data. The match of the signal data was not satisfactory. The signal values for two of the four service temperatures lay outside 3 standard deviations of the experimentally measured results. The estimated sensitivity of the die also fell outside 3 standard deviations for three of the four service temperatures. A special vector plot was developed to understand how the pressure, or packaging stress, from the EMC effected the signal and sensitivity of the sensor die. The numerical simulations were done assuming a stress free temperature of 175oC, the moulding temperature. The packaging stress was found to increase with decreasing temperature. This was the effect of the subsequent increase in ΔT as the service temperature decreased. The signal at zero pressure was found to shift as a function of temperature. This was caused by the packaging stress and a corresponding stress-field-shift on the diaphragm. The origin for this shift was an uneven packaging stress between the front and the back side of the sensor die. At -7oC, the pressure on the front and the back was 30 and 20MPa respectively. This caused an uneven bending moment on the membrane long sides and resulted in a shift in the stress field. Chapter 7 elaborated the model one step further by treating the EMC as a viscoelastic material. The result of using the viscoelastic material model showed a reduction in the packaging stress due to stress relaxation. Viscoelastic materials are temperature and strain-history dependent. It was therefore necessary to run the model through the same processes posed by the manufacturing of the MEMS and SOPs. These included a set of thermocycles between -40oC and 125oC before the signals as a function of temperature and pressure were taken. The thermocycles were found to have a positive effect on signal shifting. Less signal distortion was seen with more cycles. The estimated and measured signal- vs. temperature-values matched within two standard deviations. The estimated sensitivities did not match the experimental measurements any better than those obtained for the elastic case. It was also found that sensitivity was nearly independent on packaging stress, but significantly dependent on pressure loading conditions. The use of the viscoelastic model gave an improvement in simulated signal accuracy over the elastic model. It became clear that the EMC had to be treated as a viscoelastic material. Chapter 8 concerned the change in material properties of the EMC and the impact this had on the FEM results. It was found that the behaviour of the MEMS pressure sensor was greatly affected by such changes. Chapter 9 present the concluding remarks of this study.

Laerdal Medical lager dukker/pasientsimulatorer til medisinsk utdanning. Dette er meget avanserte dukker som i tiår har blitt anerkjent for sitt realistiske utseende og oppførsel. I den forbindelse ønsker bedriften å utvikle nye øyne som brukes i dukkene, slik at de blir enda mer virkelighetsnære. Denne oppgaven forsøker derfor å utvikle et fungerende konsept for Laerdal Medical, som innebærer at begge øynene har synkrone bevegelser i fire retninger (opp, ned, fram og tilbake), samt individuell åpning og lukking av øyelokk. I tillegg skal øynene ha iris som kan utvides og trekkes sammen. Hovedvekten av oppgaven handler om hvordan man kan lage en fungerende og funksjonell 3D-modell av konseptet, i henhold til hva Laerdal Medical ønsker. Modellen har blitt utviklet i tegneprogrammet NX, og det blir vist mange figurer underveis for å forklare hvordan de ulike delene og mekanismene settes sammen i modellen. Avslutningsvis gis en forklaring på hvordan det er tenkt at konseptet skal monteres, og hvilke materialer som kan brukes. Modellens bevegelser er testet ut, og det er gjort målinger for å se hvor stor plass modellen vil ta i dukkens hode.

1.1 Strukturen av den integrerte HT-vurderingen Konklusjonen av del én av denne oppgaven var at HT-vurderingen bør inngå som en parallell del av konseptutviklingen, som en integrert del av detaljdesignfasen og som et eget steg i form av to sjekklister. På denne måten vil integreringen av HT-vurderingen skje på en naturlig måte som gir ekstra fokus på HT i konseptutviklingen og som forsikrer at HT.komponenter vil virke godt med resten av produktet gjennom tett samarbeid i detaljutviklingsfasen. To sjekklister virker som kontrollpunkter etter første og andre fase. Resultatet av den første kan vise at HT ikke bør anvendes og utviklingen fortsetter som før. Den andre sjekklisten kontrollerer om de valgene man har gjort i konseptutviklingen er riktige. En generell firefases modell er valgt som mal for integreringen, slik at HT-vurderingen kan kombineres med de fleste andre utviklingsmetodikker. 1.2 Innholdet i HT-vurderingen 1.2.1 Sjekklistene Ved å undersøke primæregenskaper ved produktet og dets komponenter benyttes sjekklister for å vurdere om produktet sammenfaller med de sterke sidene ved HT. Ved å benytte en sjekkliste før konseptutviklingen har man mulighet til å finne et behov for HT tidlig i utviklingen. Sjekklisten etter konseptutviklingen benyttes for å kontrollerer om resultatet av konseptutviklingen ser ut til å gi god utnyttelse av HT. 1.2.2 Morfologisk tabell med fokus på ytelse Komponentene som best egner seg for HT avdekkes i første rekke gjennom bruk av en morfologisk tabell. De komponentene i det vinnende konseptet som krever HT tas med i en ny runde med konseptutvikling for HT-komponenter. 1.2.3 Designmetodikk for HT I konseptutviklingsfasen for HT-komponenter benyttes en designmetodikk for HT som baserer seg på tommelfingerreglene ”Kun bruk materiale der det er nødvendig”, ”Kun bruk additivt der det er nødvendig” og regelen om minimum 45 graders helning for å unngå støttestruktur. 1.2.4 Kriterier for god HT-design Kvaliteten av et utviklet HT-design kontrolleres og forbedres gjennom bruk av et sett med kriterier for som må oppfylles for at designet vil gi god utnyttelse av teknologien. Pliktkriteriene er generelle kriterier som er en fordel i alle tilfeller, og må innfris for å oppnå den beste utnyttelsen av teknologien. Ekstrakriteriene er de kriteriene som gir den økte ytelsen av produktet. Minst ett av disse kriteriene bør innfris for at utviklingen av teknologien skal være god. Pliktkriterier: - Lite materialsvinn/redusert maskinering - Enkel ettermaskinering - Minimal bruk av additiv tilvirkning Ekstrakriterier: - Skreddersøm - Avansert geometri - Lav vekt - Forenkler sammenstilling - Økt styrke

En løsning for to hoved lager og en bunnplate for NOWITECH 10MW referanse turbinen er foreslått basert på dimensjonering i henhold til ekstremlaster. Ekstremlastene er basert på ekstrapolerte laster under vanlig strøm produksjon for normale og ekstreme turbulens forhold spesifisert i IEC61400-3:2008 - Design requirements for offshore wind turbines [1]. Bunnplaten består av to komponenter med en total vekt på 82.4 tonn, bunnplaten har hittil ingen yaw-løsning for overføring av laster til tårnet. Styrkeanalyser er utført basert med ekstremlastene og den høyeste von Mises spenningen ble funnet til å være 208,3MPa. En konfigurasjon av et kulelager og et dobbelt konisk rullelager ble valgt ut ifra SKF sin produktkalatog. Tilslutt er videre arbeid for bunnplaten diskutert.

Filament winding is a fabrication method for composite material structures, in which fibres are wound around a rotating mandrel. It is a versatile and dexterous process especially well-suited for creating and optimizing parts with a linear rotational axis. Products like pressure tanks, golf clubs or violin bows are commonly created using this technique. The winding itself is done through software solutions that generate a CNC program for the part in question. There are several such software solutions commercially available, all with different modes of operation and functionalities. However, they are also proprietary and offer little to no access into their inner logic. To optimise a part before production Finite Element Analysis software is often used. The part in question is modelled; material, forces and constraints are applied; and an analysis is run. Currently (June 2012), there are few options available for analysing filament wound products. Modelling a part with accurate filament winding layup generally has to be done manually, in a very time-consuming process. In this thesis, the author has performed a pilot study into the development of filament winding software. Software has been developed, capable of integrating both with a filament winding machine and with Finite Element Analysis software, and operating as a link between the two. The software has functionalities to extract geometrical variables from an Abaqus mandrel model; to write G codes and create a CNC program file; simulate a filament winding process in the Abaqus viewport; and, using a CNC program file, add accurate and corresponding layup to an Abaqus part. The main goal of this thesis, however, has been to create something that will serve as a basis from which others can continue development. The intention being that the software will be open source, so that anyone and everyone using it may change, improve and add on to it.

Sperre AS produserer i stor grad hele ROV konstruksjonen sin i aluminiumslegeringen AA6082-T6. Dette er et velegnet materiale for oppgava, men med noen mangler.Denne oppgava fokuserer p&#229; elektronikksylindrene til ROV-en, disse er per idag produsert i den ovennevnte aluminiumslegeringa. Man vil i framtida ned p&#229; store havdyp, ned mot 6000 meter. N&#229;r man skal s&#229; dypt vil disse elektronikksylindrene p&#229;f&#248;re konstruksjonen mye vekt og volum, b&#229;de direkte pga st&#248;rre masse aluminium og indirekte ved at man trenger mye oppdriftsmateriale.Ved &#229; benytte seg av kompositt og egna produksjonsmetode vil man kunne produsere samme tanken, med sv&#230;rt mye bedre egenskaper. I denne oppgava er det sett p&#229; metall-innerforing for spinning av kompositt p&#229; utsida og derfor oppn&#229; &#248;nska styrke, samt generelt design av sylinderen. Det er ogs&#229; foresl&#229;tt design uten innerforing, men da produsert ved hjelp av kompositt-duk. Hvilket materiale som er best egna til innerforing og hvilken kompositt som har de beste egenskapene er ogs&#229; vurdert.Som deloppgave er det utf&#248;rt mekanisk testing p&#229; sveist aluminiumslegering for &#229; verifisere DNV standardencite{DNV271}, samt vurdere om man ved forenkla varmebehandling kan gjenopprette noe av styrken til metallet.

The governing purpose of the thesis is to develop a chair concept based on a tilting mechanism called VAPAC. This chair concept has many potential ergonomic and environmental benefits that should be included and developed in the design. The report starts with an analysis of different segments within the chair market. Based on an evaluation, office chairs was chosen as the segment for the VAPA-Chair. Due to an interesting tilting idea suggested by the Supervisor/Concept originator, a test rig was built in order to try out a chair concept using straps for the tilting mechanism. This assignment was not originally one of the main tasks in the problem definition of this thesis . Due to curiosity and expectations for the idea, it was chosen to include this assignment in the thesis. A user survey reviled that this tilting idea offered an exciting and comfortable sitting experience. The concept using straps as tilting stringers was therefore developed further and important lengths and angles regarding the tilting mechanisms were settled. A problem occurred due to the risk of the chair tilting completely around if the user leans too much forwards or backwards in the chair. Making the stringers stiff so that they can withstand pressure when introduced to a load solved this problem. The tilting function was still the same as with the regular straps because the stringers were attached in joints, allowing the stiff straps to rotate freely. An Idea using turnbuckles as stringer was developed. This solution ensured the required stiffness as well as possibilities for height adjustment and a stop mechanism for the tilting. The terms &#147;Ergonomic&#148; and &#147;Environmental friendly&#148; is introduced, and important elements from these was set as requirements for the chair concept. Design sketches, doodling and brainstorming generated ideas for different concepts. Different functional concepts was introduced and evaluated as sub-parts of the chair. One concept was chosen for each part resulting in a holistic concept for the chair.The preliminary work results in a final concept, which is presented in the form of hand sketches and a 3D model using the program NX 7.5 Mechatronics . A lot of time was spent on modeling a simple and functional design with ergonomic and environmental friendly solutions.A material analysis was conducted regarding the bearing structure of the chair using the Life cycle analysis tool Eco-indicator 99. The analysis compared aluminum and steel. Due to low environmental impact using recycled aluminum, this material was chosen for the VAPA-Chair. A life cycle analysis was also conducted on the chair using the program CES Edupack. The analysis showed that the part of the chair&#146;s lifecycle that impacts the environment the most, is the production of materials. Based on these results, it is recommended that the VAPA-Chair should focus on weight optimization of the chair and use as much recycled aluminum as possible in the production. Based on results from the report, a list of recommendations for further work is presented.

Bakgrunnen for denne oppgaven er et &#248;nske fra tilhengerprodusenten Tysse om &#229; utvikle en mer effektiv metode for &#229; beregne levetid i forskjellige punkter p&#229; deres tilhengere. Dette skal gj&#248;res ved &#229; bruke strekklapper i stedet for destruktive metoder slik som brukes i dag. Motivasjonen er &#229; spare tid og penger. Masteroppgaven er basert p&#229; prosjektoppgaven skrevet av samme studenter semesteret i forveien. Da masteroppgaven startet var teknologi og utstyr unders&#248;kt og kj&#248;pt inn. Masteroppgaven skal ta dette utstyret til en fungerende l&#248;sning. Dette kan i grove trekk deles inn i f&#248;lgende punkter:&#149;Tilpassing av m&#229;leutstyr&#149;Materialtesting&#149;Utvikling av framgangsm&#229;teM&#229;leutstyret var kj&#248;pt og mottatt da masteroppgaven startet. Brokomplettering ble evaluert og en l&#248;sning ble valgt. Dette &#229;pnet for feils&#248;king, og for &#229; bli kjent med utstyret f&#248;r testing av utstyret mot testriggen hos Tysse. Bes&#248;ket bekreftet at valgt utstyr i prosjektoppgaven faktisk fungerte under forholdene. Kompletteringsenheter ble testet under realistiske forhold, noe som f&#248;rte til utvikling av et nytt, mer robust design. Festemekanisme for m&#229;leutstyret mot tilhengeren ble pr&#248;vd ut sammen med fuktsikringen. Etter bes&#248;ket hos Tysse ble det reservert tid i utmattingslaben der pr&#248;ver av st&#229;let i tilhengeren ble testet. Dette ble gjort for ytterligere &#229; sikre realistiske resultater fra levetidsberegningene. Pr&#248;ver ble maskinert, og materialstyrke ble funnet ved strekktesting. Strekktest og utmattingstest ble gjennomf&#248;rt basert p&#229; ISO standardene ISO 6892 og ISO 1099. Estimert SN kurve ble sammenliknet med data fra utmattingstestene. Framgangsm&#229;ten for testing av tilhengere ble revurdert i masteroppgaven. Den eksisterende metoden fra prosjektoppgaven ble satt opp mot en ny og enklere l&#248;sning som skulle bli bedre tilpasset Tysse. Programvaren for bearbeiding av datamateriale ble videreutviklet og ferdigstilt. Brukermanual som beskriver framgangsm&#229;ten steg for steg ble utviklet.Sluttresultatet ble levert til Tysse i Bergen med demonstrasjon og oppl&#230;ring av dem som skulle bruke systemet videre. Det ble ogs&#229; lagt fram et forslag til videref&#248;ring av systemet.