This thesis aims to analyze the effects of geometric imperfections on the load-bearing capacity of high-strength steel grades and how the industry implements these imperfections in Finite Element Method (FEM) modeling. The goal was to examine the industry's implementation of these geometric imperfections in relation to compliance with established standards and regulations. Through conducted interviews, hand calculations, and numerical simulations, the study provided SSAB with a deeper understanding of geometric imperfections. The interview focused on handling geometric imperfections in the manufacturing of truck cranes, exploring various strategies to ensure structural integrity and compliance with industry standards. The company in focus oversized the construction in nominal analyses and followed EN 13001 and internal guidelines to prevent the effects of imperfections. A test specimen from SSAB's laboratory was used as a reference against the simulations. The test specimen consisted of a high-strength steel profile mimicking those used in cranes. The geometry of the test specimen was then applied to the numerical simulations   In numerical simulations, the flat and round sides of the test specimen were compared under compression. When the round part was in compression, the simulation underestimated the moment capacity by approximately 14 kN, equivalent to about 7.1%, compared to the actual test results. When the flat part was in compression, the simulation overestimated the moment capacity by approximately 7 kN, equivalent to 8.4%. The differences between simulations and tests were relatively small, and simulations were deemed quite representative compared to tests.   Simulations with imperfections showed marginal effects on load-bearing capacity. For the profile simulated with imperfections, the load-bearing capacity before failure was 84.5 kN, while the capacity for the profile without imperfections was 82.6 kN, with a difference of 2.24%. No major conclusions regarding the impact of imperfections can be drawn with such a small difference, but it is interesting that the profile with applied imperfections has 2.24% better load-bearing capacity than the one without. The impact of thickness on load-bearing capacity was also examined. The most significant difference noted between the ideal geometry and the one with imperfections was at a thickness of 8 mm. The main reason imperfections made the most difference there is the slenderness. Thinner thicknesses of 2, 4, and 6 mm were so slender that all would be limited by local buckling. For the larger thickness of 10 mm, the idea was that the profile becomes thick and rigid enough to avoid buckling affecting load capacity. In the case of 8 mm, the cross-section was right on the border between cross-section class 3 and 4, where imperfections take a larger part of the cross-section to class 4. It can be concluded that in cases where the part in compression is right on the verge of being so slender that cross-section reduction is almost relevant, imperfections can significantly reduce load capacity. It is noted that thicker profiles can be affected by imperfections much more than slender ones.   Hand calculations revealed differences between calculated and experimental failure loads, varying between 18% and 29%. These differences can be attributed to discrepancies in strength class and the geometry of the test component. Adjusting the strength class to 850 MPa in hand calculations improved the agreement with experiments. Geometric uncertainties include variations in thickness, where a larger thickness increases load capacity. Additional uncertainties arise for the flat part regarding cross-section reduction.   In conclusion, hand calculations align reasonably well with test results, but differences were scattered and challenging to attribute to geometric imperfections. For future studies, a closer examination of the company's method with safety factors for imperfection calculations is suggested, along with investigations into cross-sectional profiles and the transition between cross-section classes. Furthermore, the need for more simulations with different geometries is emphasized to better understand the effects of geometric imperfections.

In general, the main purpose of a structural control system is to apply powerful control techniques that improve the behaviour of civil structures under various kinds of dynamic loading. The first part of this thesis presents novel applications of posicast and input shaping control schemes that have never previously been applied in the field of structural control. Numerical simulations of a benchmark three-story building with an MR damper are used to verify the efficiency of the proposed control theories. The superiority and effectiveness of the suggested schemes at reducing the structure’s responses were demonstrated using six evaluation criteria and by comparison to results achieved with well-established classical control schemes. Moreover, a comprehensive procedure for generating scaled real ground motion records appropriate for a seismic analysis and design of structures using the linear spectrum matching technique is presented based on a seismic hazard study.To efficiently control a structure, it is necessary to estimate its real-life dynamical behaviour. This is usually done using the Structural Identification approach, which is also addressed in this thesis. Structural Identification is commonly utilized to bridge the gap between the real structure and its modeled behaviour. It can also be used to evaluate the structure’s health, detect damage, and assess efficiency. Despite the extensive development of parametric time domain identification methods, their relative merits and the accuracy with which they predict the behaviour of vibrating structures are largely unknown because there have been few comparative studies on their performance under diverse test conditions, and they have not been verified against real-life data gathered over extended periods of time.Thus, the second part of this thesis focuses on applications of parametric and non-parametric models based on the Structural Identification approach in order to clarify their potential and applicability. In addition, a new strategy is proposed that combines this approach with techniques based on Singular Value Decomposition (SVD) and Complex Mode Indicator Function (CMIF) curves to detect structural damage.The methods developed in this work are used to predict the vertical frequencies of the top storey in a multi-storey building prefabricated from reinforced concrete in Stockholm, and to detect and locate damage in a benchmark steel frame. In addition, the non-parametric structural identification approach is used to investigate variation in the modal characteristics (frequency, damping, and mode shapes) of a steel railway bridge. / <p>Godkänd; 2015; 20150303 (taredr); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Tarek Edreees Saaed Alqado Ämne: Konstruktionsteknik/Structural Engineering Avhandling: Structural Control and Identification of Civil Engineering Structures Opponent: Professor Francesc Pozo, Department of Applied Mathematics III, Escola Universitària d’Enginyeria Tècnica Industrial de Barcelona (EUETIB), Universitat Politècnica de Catalunya Comte d’Urgell, Barcelona, Spanien Ordförande: Professor Jan-Erik Jonasson vid Avd för byggkonstruktion och produktion, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Torsdag den 26 mars 2015, kl 10.00 Plats: C305, Luleå tekniska universitet</p>

Adapting a strategy concerning quality management can be an effective means for organizations striving to enhance the quality which is delivered to its customers. Especially within large infrastructure projects, which concern products with considerable production costs and long technical life spans, tending to issues regarding quality becomes important. The ISO 9000 series offers a quality management standardization framework of which a plurality of organizations have certified themselves as being practitioners. The standard encompasses quality control, quality assurance, and quality improvement as core elements in quality management. The standard also integrates management of requirements as a fundamental part, and a prerequisite, for the quality work in general. Despite the framework supplied by the ISO 9000 series there are still degrees of freedom which introduces risk. By looking at how a certified company has implemented quality management in large infrastructure projects this study is aiming to identify eventual deficiencies within the quality systems employed, and potential measures which can remediate the deficiencies. Qualitative interviews and literature studies are used to form the empirical data.  Although the study confirms substantial quality management is undertaken in such ways the delivered quality appears to be enhanced, some issues emerge. The most comprehensive issue is confirmed as the need of the company to become less dependent on its client’s ability to provide comprehensive set of requirements. Undertaken projects in general could benefit by increasing the abilities within eliciting requirements from stakeholders, which could be achieved by integrating stakeholder analysis into the processes of the company.

This report deals with environmental improvement measures in asphalt production and examines the willingness to invest in environmentally friendly technologies. The main reasons of this paper are that the asphalt industry have a large impact on the environment and the transition to green technologies is slow, and to clarify the opportunities around environmentally friendly asphalt production. The main purpose of this report is to compile relevant knowledge in the improvement of the environmental measures of the asphalt production and thus contribute to a faster reduction of carbon dioxide emissions. The questions covered are: • How has the asphalt been used over time and until? • How does the asphalt industry effect the environment? • What are the technical solutions? • What are the costs of the different technical solutions? • What is the trend for more environmentally friendly asphalt production? The thesis was concluded through literature studies, consultations with people in the asphalt industry and trough several interviews. The results of the report show that there are many different measures to reduce the environmental impacts from asphalt production, and the main challenge for producers is to choose which method is most suitable for their company. The interviews report that the willingness to invest in environmentally improving techniques exists and that the trend to produce more environmentally friendly will increase. Increased requirements and a greater demand for environmentally friendly asphalt production from customers are desired.

Organizations wants to be at the top when it comes to using new technologies in order to retain a strong position on the market and also create innovative and unique service offerings. New technologies put pressure on organizations, that have to answer to its challenges. Blockchain is a new technology that is very well heard of, it is a complicated technology and is in constant development. The purpose of this study is to identify challenges that the blockchain technology brings to organizations as well what opportunities organizations are looking with the technology. There will also be discussions about potential opportunities that arise when organizations overcome the challenges and what the blockchain can contribute to digital services. / Organisationer vill vara ledande inom nya teknologier för att skapa unika tjänsteerbjudande och behålla drivkraft. Nya teknologier sätter press på organisationer som måste besvara dess utmaningar. Blockkedjetekniken är en omtalad teknologi som har fått stor uppmärksamhet de senaste åren, tekniken är komplicerad och i ständig utveckling. Syftet med denna studie är att identifiera utmaningar som blockkedjetekniken medför till organisationer samt vad organisationer ser för möjligheter med tekniken. Det kommer att diskuteras potentiella möjligheter som uppstår när organisationer överkommer utmaningarna och vad tekniken kan bidra med till digitala tjänster. I kombination med tidigare forskning och en kvalitativ studie som utförts hos en organisation som tillhandahåller digitala tjänster och som är intresserade att investera i blockkedjan har utmaningar och möjligheter identifierats.

Purpose: Rejuvenating the water and sewer system is called a renewal step, which is a planned replacement of ground wiring in the field, which restores the operation of the wiring or improves its capacity. Most of Sweden's VA pipelines are built in the 19th century. They are now in need to be renewed. The county's in Sweden finance and manage the VA networks using a VA-tax which is paid by all users. Sweden has had a low VA-tax for many years. A low VA tax can lead that county's are not afford to replace the existing pipeline network. The purpose is to provide the reader with the knowledge that Sweden's municipalities have at the renewal stage of the VA network, and the approach to the choice of prioritization measures. Method: The work has focused on qualitative and quantitative processing in form of literature studies, document analysis and interviews. The work contains seven qualitative semi-structured and five structured interviews. The document analysis shows a clear picture of the renewal and renewal needs in VA organizations. Findings: All requested VA managers use some type of GIS system, in the category of database-based decision support systems specified by Power (2002), as a way to handle and analyse large amounts of structured data. The municipalities that are most worried about not being able to finance the renewal act are the municipalities that are small and have less resources to work with, for example, fees, work teams and civil servants. In the question of what measures must be taken to increase focus on the existing VA network and a stepping stone to the renewal act. The VA tax should be designed more according to the actual cost, despite politicians consider. This in order to avoid shock increases in the farm fee that goes against a long-term planning. Implications: The report has focused on gaining insight into why the renewal rate is too low. This may have several reasons, however VA-organizations describe that they are not used to work in decision support systems and the importance of making decisions in combination with other methods. Limitations: This thesis shows only county's decision-making process and what kind of decision support system they have in use in their operations. The thesis focuses on why the renewal pact is not prioritized higher but does not go into detail why another priority is costlier or timelier to implement. Keywords: Decision-making process, Decision Support System, Lead network, Revenue, Renewable needs, Self-sufficiency, Sewer planning, Sewage System Taxes, Water Services Act.

Den här undersökningen strävar efter att ge en bild av möjligheterna för att minska materialmängden i samverkansbroar med hänsyn till kostnadsbesparing och miljöpåverkan. Kan mindre stål användas i balktvärsnittet med bibehållen kapacitet?   Objektet för undersökningen är en samverkansbro i Gallsbo, Borlänge som projekterats av konsultföretaget Tyréns i Uppsala. Tyréns valde att dimensionera en 1100 mm hög balk som senare kort efter dimensionerades om till 1300 mm, på förfrågan från Trafikverket för att minska materialkostnaden och miljöpåverkan. Men är det den mest optimala balkdimensionen? Går det att optimera balken ännu mera. Det förklarar intresset av att göra balken än högre, vilket även är anledning till det här examensarbetet. Genom att använda företagets beräkningsmetoder har ett nytt tvärsnitt med höjden 1500 mm dimensionerats med tillräcklig bärförmåga.   Resultatet visar att det är möjligt att optimera balken ytterligare och minska mängden stål i balken med tillräcklig bärförmåga i alla dimensioneringsavseenden. I vissa dimensioneringsaspekter ökar bärförmågan samtidigt som den minskar i andra i enlighet med Eurokod. Alla kontroller visar dock att bärförmågan är fullt tillräcklig. Kostnadsbesparingen som uppkommer vid minskat tvärsnitt bör dock jämföras med kostnaden för optimeringsarbetet av balken.

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In this thesis, a theoretical model of the mechanical behaviour of jointed rock masses is developed. An equivalent material approach is used to formulate the constitutive equations, where the structural components, intact rock and joints are assigned continuous material properties. The elastic and inelastic properties of the joints are modelled by an elasto-viscoplastic formulation. The model can be used to study general stress and strain paths for both two- and three-dimensional structures based on constitutive equations, i.e. stress-strain relations or in finite element codes. The rock mass model using the equivalent material approach can be applied to hard rock masses with several sets of intersecting continuous joints. The theoretical model developed for a single joint can also be used for discrete formulation of joint elements in finite element codes, cf. chapter 3. The intact rock is treated as a linearly elastic material. The elastic behaviour of the joint is modelled with a constant stiffness matrix. The onset of plastic flow is initiated when the normal stress exceeds the normal compressive strength of the joint asperities or the tensile normal strength of the joint. the shear stress exceeds the cohesive strength and frictional resistance of the joint surface. The normal tensile strength and the cohesion of the joints are assumed to be constant material properties. The frictional parameters the dilation rate, and the shear asperity angle, and the compressive normal strength are functions of the the compressive normal strength are functions of the applied stress field and joint displacement. Simple relations based on Barton's constants joint roughness coefficient, JRC, joint compressive strength, JCS, and the residual friction angle, 0r, simple relations are fitted to these parameters. This implies that input data to the model can be extracted from the Rock Mechanics literature for a wide variety of joints. Results from laboratory shear box test and numerical calculations has been made for a number of different joints. Good agreement was obtained. It shows, that peak shear strength behaviour of joint in principal is a function of dilation rate. Further, the calculations indicated that the elastic off-diagonal behaviour of joints, reported in the rock mechanics literature, is related to the dilation angle at the asperities in contact. By means of finite element technique the model is applied to a circular opening in a jointed rock mass. It is concluded that the model offers several advantages over a discrete formulation. / Godkänd; 1985; 20070502 (ysko)

A finite difference method is presented for progressive slides in long natural slopes. The method is based on a strain softening material model. A detailed worked out example is given as well as examples using a spread sheet PC program and a PC program for Windows. Several Scandinavian slides are analysed and discussed as case studies e g Tuve (1977), Surte (1951), Bekkelaget (1953), Rollsbo (1967), Rävekärr (1971), Tre-styckevattnet (1990) and Svärtaån (1938). The nature of down-slope progressive failures in natural slopes is described and the applicability of ideal-plastic failure analysis is questioned. Principles and procedures for investigation potential landslides are presented. A short historical background to the landslide problem is given in an introductory chapter. / <p>Godkänd; 2000; 20070318 (ysko)</p>