The aim of this thesis is going to concentrate on the issues associated with the technology of mechanically anchored coating waterproofing of roofs. Today the mechanical anchoring belongs to the most widespread way of how to stabilize the layers of roofing material against the effects of wind uplift particularly in indoor buildings. However some malfunctions occur more and more frequently which cause leaking into the constructions or even the destruction of the whole roof in the worse cases. The practical part of this thesis is going to concentrate on the fasterners which belong to the most important elements of the mechanical anchored system. The aim of the experimental measurement is to draw a comparison of the quality of fasteners which are distributed on the Czech market. Thereafter the obtained figures are going to be compared with the theoretical calculating procedures according to the valid designed standards.

One-layer mechanical fastening waterproofing systems are often used within the compositions of flat roofs. Although in case of plastic based systems it is a common solution, for asphalt felts it handles about a relatively new approach, since the application of asphalt has a long history in the building industry. There are some key factors which all of the one-layer mechanically fastening systems should meet, especially water-resistance and resistance against the suction of wind. The application of dynamic loads on the joints may damage the bonds, which may lead to leakage of water. In particular the most delicate locations are the anchoring points at places where the waterproofing sheets are not connected mutually and the wind is captured. The characteristics of mechanically fastening waterproofing membranes may be verified by a specific test which is able to simulate the winds suction force, nonetheless it is quite expensive. Throughout the solution of the presented work an equipment was designed to observe the behaviour of roof compositions on smaller segments while taking into account the fastening elements, thus bringing the results closer to reality. In the first phase the presented dissertation aims to look at the possibilities of comparison of mechanically fastening bitumen reinforced sheets in a way, that they would show the extent to which the joints depend on the parameters of bitumen sheet - like the quality of the bitumen mass, the type bearing linen, the thickness of the layer or just the width of strip overlap. In the next phase the research was focused on the extent at which the strength of the resulting mechanically fastened joints is affected by the placement of fastenings elements within the strip overlap, including the possibilities when the distances from the edges of the bitumen strip cannot be maintained or because of improper geometry of fastening elements. The measurements were performed on both variants of flat roofs, thermally insulated

Syfte:  Produktionsvolymen av KL-trä har de senaste åren ökat i Sverige, vilket ligger till grund för ett ökat kunskapsbehov hos entreprenörer. Ett svenskt entreprenadföretag genomför våren 2021 sitt första projekt med KL-trästomme. Studiens mål är därför att identifiera nyckelfaktorer och förbättringsmöjligheter för ett entreprenadföretags första monteringsprocess i KL-trä. Genom det ska studien bidra till ökade kunskaper för framtida projekt i KL-trä. Metod: Studien är en fallstudie med litteraturstudier, intervjuer och observationer av ett referensprojekt. Litteraturstudier av befintlig forskning ger en förklaringsansats för erhållen empiri från intervjuer och observationer. Erhållen empiri analyseras tematiskt utifrån förklaringsansatsen och studiens frågeställningar. Resultat:  Studien visar främst på sju nyckelfaktorer och förbättringsmöjligheter vilka av studien anses relevanta att beakta vid en monteringsprocess i KL-trä. Dessa punkter är platstillverkade innerväggar, erfarenhetsåterföring, infästning, monteringsledare, personal, projektering och väderskydd. Konsekvenser:  Med hjälp av genomförd studie ska entreprenadföretag vilka genomför sina första totalentreprenader med KL-trästomme kunna ta lärdom från referensprojektets monteringsprocess. Studiens mål är att erhållna erfarenheter ska ge företag bättre förutsättningar inför framtida projekt i KL-trä. Vidare rekommenderas fler studier inom ämnet för ökade kunskaper för entreprenörer kring monteringsprocessen i KL-trä. Begränsningar:  Slutsatser och resultat rör främst totalentreprenörer vid byggnation av KL-trästomme liknande studiens referensprojekt. Eftersom studien endast rör ett referensprojekt med åtta respondenter anses resultatet inte generaliserbart. I syfte att åstadkomma ett generaliserbart resultat bör fler liknande studier i samarbete med andra företag genomföras. / Purpose:  Sweden’s production of cross laminated timber (CLT) has increased over the recent years which creates a demand of knowledge for contractors. A Swedish contactor implement their first project with a CLT-frame the spring of 2021. This study strives to identify key factors and improvements for a contractors first mounting process with CLT. Through this strives the study to contribute to increased knowledge for future projects with CLT. Method:  The study is a case-study with interviews and observations of a reference project. Document studies of existing science provides an explanatory approach for collected empirical data from interviews and observations. Collected empirical data is thematical analyzed based on the explanatory approach and the studies issues. Findings:  This study concludes mainly seven key factors and improvements who is considered relevant when implementing a mounting process with CLT. These findings are on-site manufactured indoor walls, experience feedback, fastener, mounting conductor, staff, design, and weather protection. Implications:  With this study, contractors who implement their first design and& build contracts with a CLT-frame could learn from the mounting process of the reference project. The aim of this study is that gained experiences provides contractors better prerequisites before future CLT-projects. Complementary studies regarding the subject are recommended for contractors increased knowledge of the mounting process with CLT. Limitations:  Conclusions and results from this study mainly concerns design and& build contractors mounting a CLT-frame similar with the reference project. Since the study solely concern one reference project with eight respondents, the result is not considered generalizable. To gain a generalizable result, more studies similar with this and in corporation with other companies could be done.

För att öka användandet av återbrukbara sanitetsskydd under menstruation inkontinensproblematik och som trosskydd i både utvecklade- och utvecklingsländer krävs det att sanitetsskyddet förutom att uppfylla sitt syfte, även sitter på plats och känns tryggt. För att uppnå detta krävs en komfortabel fästanordning som håller skyddet på plats. För att jobba mot en mer hållbar värld genom reducering av engångsartiklar i plast och mot ett samhälle utan mensfattigdom kan återbrukbara sanitetsskydd vara ett steg i rätt riktning. Branschstandard för återbrukbara sanitetsskydd är idag en binda med en tryckknapp som fästanordning. Tidigare studier framhäver dock en viss problematik med att fästanordningen inte håller sanitetsskyddet på plats utan att skyddet åker åt sidan under användning. För att ta fram en optimal fästanordning för återbrukbara sanitetsskydd, har tre stycken nya fästanordningar tagits fram i denna studie. Dessa fästanordningar var en silikonbeläggning applicerad under skyddet, ett ruggat polyestertyg applicerad på skyddets undersida och två stycken silikonband fastsydda i underbyxans gren för sanitetsskyddet att fästas mellan. Dessa tre kom sedermera att jämföras med den redan etablerade fästanordningen med tryckknapp. Studien baserades på en kvalitativ undersökning som genomfördes av sex kvinnor mellan 25-63 år som förde logg om sina upplevelser av de fyra olika fästanordningarna. Den kvalitativa studien fördes parallellt med en kvantitativ studie i form av ett tvätt-, kraft- och friktionstest för att mäta och jämföra de olika fästanordningarnas hållbarhet i relation till tvätt och användning. Det kvalitativa testet visade på att fästanordningen med tryckknapp och fästanordningen med silikonband integrerade i underbyxa var mest komfortabla och kändes säkrast. Från de kvantitativa testerna presterade silikonbanden integrerade i underbyxa bäst och bekräftar den kvalitativa undersökningen. Däremot riktades kritik från respondenterna kring långsiktigt användande, hygien, utseende och hållbarhet mot fästanordningen med silikonband. Efter resultatanalys kan slutsatsen dras att känslan av psykisk komfort är viktig och att känslan av trygghet infinner sig när sanitetsskyddet är ordentligt fast i underbyxan. Med kritiken i beaktning samt tvättestets resultat som visade på en antydan till slitage av polyesterns kanter, kan en kombination med tryckknapp och silikonbeläggning rent hypotetiskt vara en optimal fästanordning. / In order to encourage the use of reusable sanitary pads for: incontinence problems, panty liners and menstruation in both developed and developing countries alike, a sanitary pad which feels secure and sits in place, whilst also maintaining its functionality, is required. To achieve this a convenient fastening device that holds the sanitary pad in place is necessary. This in turn, helps create a more sustainable planet by reducing single-use plastic items, whilst simultaneously reducing menstrual poverty. Today, the industry standard for reusable sanitary protection is a pad with a press stud as its fastening device. However, previous studies highlight a particular problem with this pad, in which the fastening device does not hold the sanitary protection properly in place. Instead the press stud design has been shown to consistently move to the side for the user, therefore causing discomfort. In order to develop an optimal fastening device for reusable sanitary pads, this study developed three new fasteners: a sanitary pad with a silicone coating applied underneath the pad, a sanitary pad with a coarse polyester fabric on its underside, and a pair of regular underpants with silicon bands sewn in to allow for a pocket for the sanitary pad. These three designs have been developed to compare with the already established press stud fastener. The study was based on a qualitative survey of six women between the ages of 25-63 who kept a log of their experiences testing the four different fasteners that were applied to a reusable pad. The qualitative study was carried out in parallel with a quantitative study in the form of a: washing, force and friction test to measure and compare the durability of the various fasteners in relation to washing and use. The qualitative test showed that the fastener with a press stud and the fastener with silicone bands sewn into the underpants, were the most comfortable and felt the most secure. From the quantitative tests, the silicone bands sewn into the underpants performed best and confirmed the qualitative investigation. After analyzing the results, a conclusion can be drawn that the feeling of psychological comfort is of upmost importance for users. Based on the qualitative and quantitative results, silicone bands integrated into underpants performed best for its purpose. On the other hand, criticism from the respondents regarding long-term use, hygiene, aesthetics and durability was directed at this fastening device. Taking the criticism into account and the results of the washing test where signs of wear and tear were shown on the polyester fabric, a combination with a press stud and silicone coating could hypothetically be the optimal fastening device.

The railway system is an important part of the sociotechnical society, as it enables efficient, reliable, and sustainable transportation of both people and goods. Despite increasing investments, the Swedish railway has encountered structural and technical problems due to worn-out infrastructure as a result of insufficient maintenance. Two important technical aspects of the rail are the stability and robustness. To prevent transversal and longitudinal deviations, the rail is attached to sleepers by fasteners. The fasteners’ conditions are therefore crucial for the stability of the track and the safeness of the railway. Automatic fastener inspections enable efficient and objective inspections which are a prerequisite for a more adequate maintenance of the railway. This master thesis aims to investigate how machine learning can be applied to the problem of automatic fastener fault detection. The master thesis includes the complete process of applying and evaluating machine learning algorithms to the given problem, including data gathering, data preprocessing, model training, and model evaluation. The chosen model was the state-of-the-art object detector YOLOv5s. To assess the model’s performance and robustness to the given problem, different settings regarding both the dataset and the model’s architecture in terms of transfer learning and hyperparameters were tested.  The results indicate that YOLOv5s is an appropriate machine learning algorithm for fastener fault detection. The models that achieved the highest performance reached an mAP[0.5:0.95] above 0.744 during training and 0.692 during testing. Furthermore, several combinations of different settings had a positive effect on the different models’ performances.  In conclusion, YOLOv5s is in general a suitable model for detecting fasteners. By closer analysis of the result, the models failed when both fasteners and missing fasteners were partly visible in the lower and upper parts of the image. These cases were not annotated in the dataset and therefore resulted in misclassification. In production, the cropped fasteners can be reduced by accurately synchronizing the frequency of capturing data with the distance between the sleepers, in such a way that only one sleeper and corresponding fasteners are visible per image leading to more accurate results. To conclude, machine learning can be applied as an effective and robust technique to the problem of automatic fastener fault detection.

O presente trabalho consiste basicamente num estudo experimental de juntas híbridas metal-compósito unidas mecanicamente por fixadores. Foram analisadas juntas fabricadas através de uma chapa metálica de titânio unida a uma placa em compósito de fibra de carbono e resina epóxi por fixadores de monel. As juntas avaliadas são juntas simples (\"single lap joint\"), ou seja, as mesmas foram submetidas ao simples cisalhamento. Antes, porém, dos ensaios das juntas, foram fabricados corpos-de-prova (CDPs) do compósito seguindo as especificações das normas ASTM D3039 e ASTM D3518. Os ensaios de tração e cisalhamento dos CDPs de compósito possibilitaram a determinação de propriedades mecânicas, bem como de valores de resistência. Sob posse das propriedades e resistência média, foram executadas simulações computacionais via Método dos Elementos Finitos com o intuito de prever o comportamento mecânico das juntas a serem ensaiadas seguindo a norma ASTM D5961 e, assim, delinear estratégias para os ensaios. Os ensaios das juntas foram realizados, possibilitando assim a avaliação do comportamento mecânico de juntas híbridas e de seus mecanismos de falha. Por fim, as conclusões e as perspectivas para trabalhos futuros foram apresentadas. / This work consists on an experimental investigation of hybrid joints (metal-composite) joined by fasteners. For this work, hybrid joints of titanium joined to composite (carbon fiber with epoxy resin) by monel fasteners were manufactured. Only single lap joints were investigated. However, before manufacturing specimens of joints, composite specimens were tested following the ASTM D3039 e ASTM D3518. The tensile and shear tests provided the mechanical properties and strength values of the composite. Finite element analyses of the hybrid joints were carried out, using average mechanical properties and strength values. These simulations followed the specifications of ASTM D5961 in order to predict the mechanical behavior of the joints during the experimental tests, as well as, provide a good strategy for the test setup. The experimental tests were carried out, observing the mechanical behavior and failure mechanisms of the hybrid joints. Finally, the conclusions and perspective of future works were showed.

Two failure mechanisms in a double lap joint are investigated. Analytical models of net-section and gross-section failure modes are proposed to describe these mechanisms. The effects of lamping force, interference fit, maximum axial load and WDCP on fatigue performance of the joint are included in the models. The effect of WDCP is assumed to give a reduction in friction coefficient. Three types of stress reduction factors are proposed in the net-section failure model to account for these parameters. The stress reduction factors modify stress range that is used in crack growth calculation. If there are no effects of these parameters, the stress reduction factors are equal to one. Two types of fretting stress are introduced in gross-section failure model to describe either sliding contact or incipient sliding contact on faying surface. The fretting stress is combined with body stress to modify stress range. The net-section failure model predicts that fatigue life is increasing as interference fit, clamping force and friction coefficient increase. The gross-section failure model predicts that fatigue life is decreasing as clamping force and friction coefficient increase. Both models predict that fatigue life is decreasing as maximum axial load increases. Transition of the failure mode occurs earlier as friction coefficient and interference fit increase, while it is delayed as maximum axial load increases. A transition parameter is proposed to establish a relationship between the four main parameters. The transition parameter is expressed in a polynomial equation. It gives an optimum combination of the four main parameters in order to achieve relatively higher fatigue life by having gross-section failure mode. Finite element analysis and fatigue testing are performed to validate the models. The finite element and the analytical models show that stress concentration factor at the edge of the hole is decreasing as clamping force increases. The rate of decrease of stress concentration factor is increasing as friction coefficient increases. While stress concentration factor on the faying surface is increasing as clamping force and friction coefficient increase. Fatigue testing reveals that the fatigue life of the joint is in good agreement with the predicted fatigue life of the proposed models.

O presente trabalho consiste basicamente num estudo experimental de juntas híbridas metal-compósito unidas mecanicamente por fixadores. Foram analisadas juntas fabricadas através de uma chapa metálica de titânio unida a uma placa em compósito de fibra de carbono e resina epóxi por fixadores de monel. As juntas avaliadas são juntas simples (\"single lap joint\"), ou seja, as mesmas foram submetidas ao simples cisalhamento. Antes, porém, dos ensaios das juntas, foram fabricados corpos-de-prova (CDPs) do compósito seguindo as especificações das normas ASTM D3039 e ASTM D3518. Os ensaios de tração e cisalhamento dos CDPs de compósito possibilitaram a determinação de propriedades mecânicas, bem como de valores de resistência. Sob posse das propriedades e resistência média, foram executadas simulações computacionais via Método dos Elementos Finitos com o intuito de prever o comportamento mecânico das juntas a serem ensaiadas seguindo a norma ASTM D5961 e, assim, delinear estratégias para os ensaios. Os ensaios das juntas foram realizados, possibilitando assim a avaliação do comportamento mecânico de juntas híbridas e de seus mecanismos de falha. Por fim, as conclusões e as perspectivas para trabalhos futuros foram apresentadas. / This work consists on an experimental investigation of hybrid joints (metal-composite) joined by fasteners. For this work, hybrid joints of titanium joined to composite (carbon fiber with epoxy resin) by monel fasteners were manufactured. Only single lap joints were investigated. However, before manufacturing specimens of joints, composite specimens were tested following the ASTM D3039 e ASTM D3518. The tensile and shear tests provided the mechanical properties and strength values of the composite. Finite element analyses of the hybrid joints were carried out, using average mechanical properties and strength values. These simulations followed the specifications of ASTM D5961 in order to predict the mechanical behavior of the joints during the experimental tests, as well as, provide a good strategy for the test setup. The experimental tests were carried out, observing the mechanical behavior and failure mechanisms of the hybrid joints. Finally, the conclusions and perspective of future works were showed.

Byggsektorn tenderar idag att välja material med låg miljöpåverkan och bygga energi- och tidseffektiva konstruktioner. Att öka användningen av träprodukter är en del av lösningen. Korslimmat trä (KL-trä) är ett byggmaterial som har blivit mer och mer populärt att använda i byggbranschen. I Sverige har KL-trä använts sedan slutet på 90- talet och användandet ökar för varje år som går. Materialet är relativt nytt och vid monteringen av KL-trä finns det utrymme för förbättringar. Syftet med arbetet är att undersöka och analysera hur dagens infästning av KL-element utförs och hur dessa kan effektiviseras. Målet är att undersöka om det går att korta ner monteringstiden av KL- trästommar. Detta görs genom beräkningar, fältstudie och experiment. I arbetet undersöks möjligheten att reducera skruvning för det vanligast använda vägg till golv anslutningarna och om det finns tid att spara i montaget med hjälp av förborrning. Resultatet av rapporten visar att det finns en potentiell tid motsvarande ca 40 % tidsvinst att spara med förborrade bjälklag från fabrik och andra kvalitétsfördelar som förborrning kan medföra, medan reducering av skruv är möjligt men inte optimerad för dagens mest tillämpade infästningslösningar. / The construction sector today tends to choose material with a low environmental impact and build energy- and time-efficient structures. Increasing the use of wood products is part of the solution. Cross laminated timber (CLT) is a building material that has become more and more popular to use in the construction industry. In Sweden, CLT has been used since the late 90 and its use is increasing every year. The material is relatively new and especially for mounting CLT element, there are still potentials for improvement. The purpose of the work is to investigate and analyze how todays attachment of CLT elements is carried out and how these can be made more efficient. The aim is to investigate whether it is possible to shorten the assembly time of CLT elements. The study was carried out through calculations, study visit and experiments. The work investigates the possibility of reducing screwing for the most commonly used wall to floor joints and showed there is a potential time efficiency of about 40% to be gained with pre-drilled floor element from the factory and other quality benefits that pre-drilling can bring, while the study also showed reducing fasteners under construction phase is possible but not an optimal solution.

Die Präsentation stellt kurz die Grundlagen der Berechnung von Schraubenverbindungen in Anlehnung an die VDI-Richtlinie 2230 Teil 1 dar. Auch die vier FEM-Modellklassen, die die VDI 2230 Teil 2 (Entwurf) zur Berechnung von Mehrschraubenverbindungen vorschlägt, werden behandelt, und die in Creo Simulate vorhandenen Softwarefeatures zu deren Umsetzung vorgestellt. Es folgt eine Darstellung, was bei der Linearisierung von Schraubenverbindungen zur vereinfachten Berechnung zu beachten ist, und wieso bei der Berechnung im FEM-System dann nicht notwendigerweise eine Vorspannung benötigt wird. Ausführlich wird das neue Schraubenfeature in Creo Simulate betrachtet, das eine weitgehend automatisierte Modellierung und Berechnung von Standardverschraubungen erlaubt. Weitere Features, wie die neuen Vorspannelemente, werden erläutert, sowie auch die Grenzen der Software aufgezeigt. Abschließend werden zwei anspruchsvolle Anwendungsbeispiele vorgestellt: Eine zentrisch belastete Verschraubung mit Berücksichtigung von Elasto-Plastizität und einer komplexen Lasthistorie (Anziehen durch Anzugsmoment, Setzeffekte, Entfall des Torsionsmomentes durch das Anziehen, Betriebskraft) sowie eine exzentrisch belastete Verschraubung, die wegen eines relativ dünnen Flansches starke Biegezusatzbeanspruchungen erfährt. / The presentation shows the foundations of bolt analysis according to VDI-guideline 2230 part 1. In addition, the four FEM model classes proposed in VDI 2230 part 2 (draft) are described, as well as the features available in Creo Simulate to realize these model classes. Next, the presentation shows the requirements for linearizing bolted connections, and why in a FEM analysis with a linearized connection no preload is necessary. The new fastener feature introduced in Creo Simulate is explained in detail. This feature allows the automated modeling and analysis of bolted connections having standard geometry. Further software features, like pretension elements, as well as the current software limitations are shown. Finally, two advanced application examples are shown: A centrically loaded bolted connection taking into account elasto-plasticity and a complex load history (tightening torque, embedding, removal of tightening stress, operational load), and an eccentrically loaded flange connection, which is subjected to high additional bending loads because the flange is relatively thin.