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  • 251.
    Kärnbo, Josua
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Svensk Byggindustri och Critical Success Factors: En lokal diskussion kring kritiska moment vid implementering av BIM2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    BIM (Building Information Modeling) is an exponentially growing field within the construction industry, with no signs of slowing down. However, as the process continues to spread on both an international and national scale, issues with implementation inevitably arise due to many different factors, in this work identified as CSF (Critical Success Factors).

    The purpose of this work is therefore to examine these factors, as well as the term CSF itself, with regards to meaning and relevance. Based on previous studies the term CSF, as well as 14 factors, were established. To correlate these internationally described factors to the Swedish market, five interviews featuring people with experience of BIM in Sweden were conducted, after which similarities and patterns could be recognized.

    The core concepts continually established throughout the work was the value of mutual and shared understanding, as well as the importance of utilizing previously established knowledge within the construction industry. The report concludes that the identified factors as well as the term CSF are both valid and beneficial for future discussions and implementations of BIM

  • 252.
    Laine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Tillbudsrapportering inom JM: En analys av förbättringsarbetet2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction business is one of the most accident prone businesses in Sweden. In order to make it safer it’s vital that all employees of a company report all accidents and incidents that occur. This report intends through qualitative interviews, to analyze the knowledge and attitude towards incident reporting among the employees of the Swedish construction contractor JM.

    The goal of the thesis work is to hopefully contribute to an increase of employees’ awareness on those issues. This report also intends to analyze why not all of the occurring incidents are reported and which measures can be taken in order to increase the number of reported incidents.

    The study shows that the knowledge towards incidents and accidents is diverse among all employees. Many employees are having difficulties defining what incidents are to be reported and many craftsmen don’t know how and why they should report an incident. The major differences are on the one hand between craftsmen and white-collar workers, and on the other hand between senior employees and new recruits.

    In order to increase the number of reported incidents, JM can introduce incident report pads to be carried by their employees at all time. They can also continue educating their employees in why it’s important to report all incidents and how to complete a report.

  • 253.
    Larsson, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Effektivare dimensionering av en pålplatta: Ett fördtydligande av beräkningsgången enligt Eurokod2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Design of pile caps in accordance with SS-EN-1992-1-1:2005 Eurocode 2 is a time-consuming work when calculations are performed by hand. This thesis intends to investigate whether it is possible to streamline the design of pile caps with a self-developed computational tool. The tool streamlines the design of new pile caps and performing a verification of existing pile caps. This thesis will also provide a clarification of the calculation of pile caps according to current standards. The possibility of streamlining the design of a pile cap is presented by a case study where an existing pile cap is controlled with the computational tool. A conclusion is drawn whether it is possible to increase the load on the column or not. The result of this work is the computational tool, and the report itself. The computational tool is considered to be a more efficient way of designing pile caps. Exactly how much time saved is not investigated. 

  • 254.
    Larsson, Jon
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Jidling, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Outsourcing av UAS-data: Informationshantering av data insamlad viaUAS2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This reports purpose is to give a general view on how to handle information collectedthrough photogrammetry and laser scanning with the help of UAS. The report ismade in collaboration with WSP Group and will briefly describe howphotogrammetry and laser scanning, also known as Lidar, works and how those areused in the construction business today. Then the focus will be on how gathered datais handled today, how outsourcing of data should be approached and if there are anyconsequences if data is handled in the wrong way. Interviews have been made with allparts in the UAS business. That includes authorities as Transporstyrelsen,Försvarsmakten. Interviews have also been conducted with consultants that operatethese systems, distributors of the different systems and solicitor. What can been seenis that, today, outsourcing and cloud services are not used to a great extent andtherefore not many have felt the obligation to familiarize themselves with theregulations.Based on the interviews and studies of relevant laws the conclusion can be made that,even if the purpose is not to publish the material when you outsource, it should stillbe treated as a publication.The penalties, when material is handled in the wrong way, are usually up to one yearin prison but if there is severe mismanagement it can be a matter of national securityand can be classified as espionage. Then the penalties are much harder.

  • 255.
    Larsson, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Terner, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Förstärkning av betongkonstruktioner med kolfiber med avseende på olika brottstyper2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to simplify the process of designing carbon fiber strengthening for existing concrete constructions, specifically beams. The intention has been to establish a flow chart containing information on the necessary testing and calculations for the design, to as far degree it is possible satisfy the requirements stipulated by Swedish and by extension, European authorities.To do this the report will examine a parking garage situated underground by Akademiska Sjukhuset, Uppsala. The parking garage was built in the mid-seventies, and has in recent years been subjected to a greater load than designed for by the construction of a road on top of it. FEM-Design has been used to obtain the internalforces of the beams and thereby determine whether they are in need of strengthening or not and thereafter design the strengthening according to Täljsten (2006) with some corrections from Täljsten (2011) due to new regulations.The result of this report is that the flow chart used is viable to design carbon fiber strengthening, atleast with the conditions met in our reference project.The conclusion drawn after working with this report is that there is a need for a clear standard for carbon fiber strengthening , preferably a standard that can be used throughout Europe.

  • 256. Leppanen, Kirsi
    et al.
    Bjurhager, Ingela
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Peura, Marko
    Kallonen, Aki
    Suuronen, Jussi-Petteri
    Penttila, Paavo
    Love, Jonathan
    Fagerstedt, Kurt
    Serimaa, Ritva
    X-ray scattering and microtomography study on the structural changes of never-dried silver birch, European aspen and hybrid aspen during drying2011In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 65, no 6, p. 865-873Article in journal (Refereed)
    Abstract [en]

    The impact of drying on the structure of the never-dried hardwood cell wall was studied at nanometer level by means of wide- and small-angle X-ray scattering (WAXS, SAXS), and at micrometer level by X-ray microtomography (mu CT). Never-dried silver birch, European aspen and hybrid aspen samples were measured by WAXS in situ during drying in air. The samples included juvenile and mature wood, as well as normal and tension wood to allow comparison of the effects of different matrix compositions and microfibril angles. The deformations of cellulose crystallites and amorphous components of the cell wall were detected as changes in the cellulose reflections 200 and 004 and amorphous halo in the WAXS patterns. Especially, the width of the reflection 004, corresponding to the cellulose chain direction, increased due to drying in all the samples, indicating an increase of strain and disorder of the chains. Also, the cellulose unit cell shrank 0.2-0.3% during drying in this direction in all the samples except in hybrid aspen tension wood. According to the SAXS results of silver birch, the distance between microfibrils decreased during drying. It was detected by mu CT that the mean cross-sectional maximum width of the parenchymatous rays decreased from that of never-dried to air-dried birch by roughly 16%.

  • 257.
    Lidén, Ewa
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Interaction between High-velocity Penetrators and Moving Armour Components2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This work was aimed at understanding mechanisms of importance for the design of weight-efficient armour against long-rod projectiles (LRP) and shaped charge (SC) warheads. The focus was on how to achieve effective mechanical disturbances on the threat before it hits the target.

    Methods were developed for laboratory tests in full and reduced scale, and for registration and evaluation of the fast and violent events involved. For numerical simulations, the Xue-Wierzbicki fracture model was implemented and used for the LRP in order to allow fractures due to shear load without extensive damage of the entire projectile. In order to reproduce the scattering of the SC jet after interaction with reactive armour, use was made of a very fine computational mesh.

    Severe disturbances and fractures of the penetrators (LRP and SC jet) originate from the interaction phase in which a plate slides along the penetrator. In the case of an SC jet, this sliding contact results in severe scattering of the SC jet due to instabilities of the same kind as those between two fluids in contact, moving in parallel with different tangential velocities (Kelvin-Helmholtz instabilities). The generation of such instabilities is caused by the very high velocity (in the order of 10000 m/s) and the relatively low material strength of the SC jet in combination with the high contact pressure and the motion of the plate. In the case of an LRP, the high strength of the material of the projectile and its low velocity (in the order of 2000 m/s) relative to that of an SC jet, prevent the generation of KH-instabilities. Instead, fractures of the projectile may occur due to abrupt change of contact pressure at the exit of the plate. The positive pressure gradient and longer interaction time of forwards moving plates compared to backwards moving plates make the former plates more effective. A side-hitting steel rod gives approximately the same effect on an LRP as that of a steel plate with the same thickness, velocity and angle of obliquity.

    The results obtained can be used for assessment and optimisation of reactive armour modules and active protection systems.

    List of papers
    1. Effect of thin oblique moving plates on long rod projectiles: a reverse impact study
    Open this publication in new window or tab >>Effect of thin oblique moving plates on long rod projectiles: a reverse impact study
    2006 (English)In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 32, no 10, p. 1696-1720Article in journal (Refereed) Published
    Abstract [en]

    The geometry and motion of long rod projectiles after penetrating thin obliquely oriented and moving armour plates were studied. Plates moving in their normal directions towards as well as away from the projectile (scalar product of velocities negative and positive, respectively) were considered. The influences of plate velocity and obliquity (angle between the normal of the plate and the axis of the projectile) were investigated through small-scale reverse impact tests with tungsten projectiles of length 30 mm and diameter 2 mm, and with 2 mm-thick steel plates. The obliquity (30°, 60° and 70°) and the plate velocity (300 to −300 m/s) were varied systematically for a projectile velocity of 2000 m/s. The disturbing effect of the plate on the projectile was characterised in terms of changes in length, velocity, angular momentum, linear momentum and kinetic energy. Plates with obliquity 60–70° moving away from the projectiles with velocity 200–300 m/s were found to cause extensive fragmentation of the projectile and to have large disturbing effects in terms of all measures used.

    Keywords
    Oblique plate, Reactive armour, Long rod projectile, Residual projectile, Reverse impact, Test, Experiment
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-70699 (URN)10.1016/j.ijimpeng.2005.02.004 (DOI)
    Available from: 2007-02-14 Created: 2007-02-14 Last updated: 2017-11-21Bibliographically approved
    2. Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Numerical simulations
    Open this publication in new window or tab >>Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Numerical simulations
    2012 (English)In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 40-41, p. 35-45Article in journal (Refereed) Published
    Abstract [en]

    Simulations have been performed to evaluate the possibility of reproducing the fragmentation of a long-rod projectile impacted by a moving oblique plate. When the moving plate slides along the projectile, fractures due to shear loading may occur in the projectile. Therefore, a fracture model suggested by Xue–Wierzbicki was used for the projectile together with the Johnson–Cook strength model. This fracture model is based on an equivalent plastic strain of fracture which depends on a stress triaxiality and a deviatoric stress parameter. The results of the simulations were compared with experimental results of a preceding study in which the impact conditions were varied in such a way that the projectile fractured in some but not all tests. The comparisons show that the simulations reproduced the fractures in the projectile well. Also, the transition from a deformed non-fractured to a severely fractured projectile was captured. The benefit of including the deviatoric stress parameter and the mechanisms leading to fragmentation of the projectile are discussed.

    Keywords
    Reactive armour, Oblique plate, Long-rod projectile, Fracture model, Numerical simulation
    National Category
    Engineering and Technology
    Research subject
    Engineering science with specialization in Applied Mechanics
    Identifiers
    urn:nbn:se:uu:diva-132940 (URN)10.1016/j.ijimpeng.2011.09.003 (DOI)000298460600005 ()
    Available from: 2010-10-29 Created: 2010-10-29 Last updated: 2017-12-12Bibliographically approved
    3. Influence of side impacting dynamic armour components on long rod projectiles
    Open this publication in new window or tab >>Influence of side impacting dynamic armour components on long rod projectiles
    2007 (English)In: / [ed] Francisco Gálvez, Vicente Sánchez-Gálvez, 2007Conference paper, Published paper (Refereed)
    Abstract [en]

    (LRP) before they hit the basic armour is a weight efficient way of in-creasing the protection of lighter vehicles. In this study, the effect of moving armour components, in the form of one or three cylindrical rods, hitting the side of the LRP, was investigated. The rods were hit-ting the side of the LRP at an angle of attack of 60 degrees. Rod ve-locities of 200 and 600 m/s and hitting points in the front and in the middle of the LRP were studied. The velocity of the LRP was 2000 m/s. The study is based on small scale reverse impact experiments and continuum dynamic simulations.To break the LRP, high rod velocities must be used. One rod hitting the LRP at 200 m/s gives approximately the same effect (some yaw but no fracture) as that of a moving oblique plate having the same ve-locity and angle of obliquity. Increasing the velocity of the rod to 600 m/s resulted in fracture of the LRP closely behind the hitting point both when hitting the front and the middle of the LRP. When using three rods, fracture was only obtained when the hitting points of the rods were closely spaced.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-132939 (URN)
    Conference
    International Symposium on Ballistics,23rd International Symposium on Ballistics, Tarragona, Spain, 16-20 April 2007
    Available from: 2010-10-29 Created: 2010-10-29 Last updated: 2016-04-07Bibliographically approved
    4. Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Experimental test
    Open this publication in new window or tab >>Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Experimental test
    2011 (English)In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 38, no 12, p. 989-1000Article in journal (Refereed) Published
    Abstract [en]

    The influence of projectile length to diameter ratio (15, 30 and 45), plate thickness (0.5, 1 and 2 projectile diameters), projectile velocity (1500, 2000 and 2500 m/s) and plate velocity (−300 to 300 m/s) on the interaction between long-rod tungsten projectiles and oblique steel plates (obliquity 60°) was studied experimentally in small-scale reverse impact tests. The residual projectiles and their motions were characterised in terms of changes in length, velocity, angular momentum, linear momentum and kinetic energy. The parameters found to have the largest influence on the disturbance of the projectile were the plate velocity, in particular its direction, and the thickness of the plate. In the ranges studied, the influence of length to diameter ratio and of projectile velocity were found to be less important.

    Keywords
    Reactive armour, Oblique plate, Long-rod projectile, Small scale, Reverse impact
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-132938 (URN)10.1016/j.ijimpeng.2011.07.002 (DOI)000296680700007 ()
    Available from: 2010-10-29 Created: 2010-10-29 Last updated: 2017-12-12Bibliographically approved
    5. The role of Kelvin-Helmholz instabilities on shaped charge jet interaction with reactive armour plates
    Open this publication in new window or tab >>The role of Kelvin-Helmholz instabilities on shaped charge jet interaction with reactive armour plates
    2010 (English)In: Journal of applied mechanics, ISSN 0021-8936, E-ISSN 1528-9036, Vol. 77, no 5, p. 051805-Article in journal (Refereed) Published
    Abstract [en]

    Reactive armor panels have been used for many years as very efficient add-on armoragainst shaped charge warheads. The main features of the defeat mechanisms of thearmor are therefore well known. The origin of the irregular disturbances on the shapedcharge jet, which leads to the severe fragmentation and scattering of the jet, is howevernot described in literature. As this scattering of the jet provides the main protectionmechanism of the armor, it is of interest to understand the details of the interaction andthe origin of the disturbances. Some experimental observations have been made showingthat the backward moving plate often displaces the jet relatively smoothly while it is theinteraction with the forward moving plate that causes the disturbances that leads tofragmentation and scattering of the jet. In this work, a mechanism for the interaction isproposed based on the theory of Kelvin–Helmholtz instabilities, which explains the originof the disturbances on the jet due to the interaction with the forward moving plate.Numerical simulations have been performed to show the difference in the mechanisms ofbackward and forward moving plates when interacting with the jet. The impact angle ofthe plate seems to be the dominant parameter for the onset of instabilities. A parametricstudy has also been performed on how different interaction and material parametersinfluence the development of instabilities of the interface between the jet and the armorplate. The parametric study shows that low-strength jets promote development of instabilities,a tendency that is amplified by frictional forces between the materials. Theinfluence of the plate strength is more complex due to the influence of the structuralstability on the contact forces. The effect of friction and melting of the metals in theboundary layer to the development of the instabilities is discussed. A microscopic study ofthe edge of the penetration channel has been made, which shows that the materials havebeen melted during the interaction between the plate and the jet.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-132941 (URN)10.1115/1.4001738 (DOI)
    Available from: 2010-10-29 Created: 2010-10-29 Last updated: 2017-12-12Bibliographically approved
  • 258. Lidén, Ewa
    et al.
    Andersson, Olof
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Experimental test2011In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 38, no 12, p. 989-1000Article in journal (Refereed)
    Abstract [en]

    The influence of projectile length to diameter ratio (15, 30 and 45), plate thickness (0.5, 1 and 2 projectile diameters), projectile velocity (1500, 2000 and 2500 m/s) and plate velocity (−300 to 300 m/s) on the interaction between long-rod tungsten projectiles and oblique steel plates (obliquity 60°) was studied experimentally in small-scale reverse impact tests. The residual projectiles and their motions were characterised in terms of changes in length, velocity, angular momentum, linear momentum and kinetic energy. The parameters found to have the largest influence on the disturbance of the projectile were the plate velocity, in particular its direction, and the thickness of the plate. In the ranges studied, the influence of length to diameter ratio and of projectile velocity were found to be less important.

  • 259.
    Lidén, Ewa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Andersson, Olof
    Tjernberg, Anders
    Influence of side impacting dynamic armour components on long rod projectiles2007In: / [ed] Francisco Gálvez, Vicente Sánchez-Gálvez, 2007Conference paper (Refereed)
    Abstract [en]

    (LRP) before they hit the basic armour is a weight efficient way of in-creasing the protection of lighter vehicles. In this study, the effect of moving armour components, in the form of one or three cylindrical rods, hitting the side of the LRP, was investigated. The rods were hit-ting the side of the LRP at an angle of attack of 60 degrees. Rod ve-locities of 200 and 600 m/s and hitting points in the front and in the middle of the LRP were studied. The velocity of the LRP was 2000 m/s. The study is based on small scale reverse impact experiments and continuum dynamic simulations.To break the LRP, high rod velocities must be used. One rod hitting the LRP at 200 m/s gives approximately the same effect (some yaw but no fracture) as that of a moving oblique plate having the same ve-locity and angle of obliquity. Increasing the velocity of the rod to 600 m/s resulted in fracture of the LRP closely behind the hitting point both when hitting the front and the middle of the LRP. When using three rods, fracture was only obtained when the hitting points of the rods were closely spaced.

  • 260.
    Lidén, Ewa
    et al.
    FOI, Stockholm.
    Mousawi, Saed
    FOI, Stockholm.
    Helte, Andreas
    FOI, Stockholm.
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Deformation and fracture of a long-rod projectile induced by an oblique moving plate: Numerical simulations2012In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 40-41, p. 35-45Article in journal (Refereed)
    Abstract [en]

    Simulations have been performed to evaluate the possibility of reproducing the fragmentation of a long-rod projectile impacted by a moving oblique plate. When the moving plate slides along the projectile, fractures due to shear loading may occur in the projectile. Therefore, a fracture model suggested by Xue–Wierzbicki was used for the projectile together with the Johnson–Cook strength model. This fracture model is based on an equivalent plastic strain of fracture which depends on a stress triaxiality and a deviatoric stress parameter. The results of the simulations were compared with experimental results of a preceding study in which the impact conditions were varied in such a way that the projectile fractured in some but not all tests. The comparisons show that the simulations reproduced the fractures in the projectile well. Also, the transition from a deformed non-fractured to a severely fractured projectile was captured. The benefit of including the deviatoric stress parameter and the mechanisms leading to fragmentation of the projectile are discussed.

  • 261.
    Lind, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Utmattning av järnvägsbroar i armerad betong: Enligt eurokoder2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Commissioned for this report is Ramboll, Bridge and Tunnel Unit in Stockholm. The

    idea throughout the work has been to primarily help bridge designers compiling

    advice and instructions on how fatigue verification for railway bridges in reinforced

    concrete shall be performed under the new rules, the Eurocodes.

    After the introduction of the Eurocodes in 2011 has major problems emerged among

    designers around Sweden. In some areas, it differs in the calculation rules compared

    with rules from the Swedish Transport Administration and the National Board of

    Housing, Building and Planning calculation. Fatigue verification is one area where the

    new calculation rules are different from the past.

    A large part of the report has been to interpret and find the relevant information in

    the Eurocodes concerning fatigue. When questions or doubts have surfaced, this has

    been discussed with Elisabeth Helsing at the Swedish Transport Administration and

    bridge designers at Ramboll.

    The result is a report where the structure is organized in the way that the bridge

    designers can move from cover to cover and realize that fatigue verification in reality

    follows the same order as the report's sections. The issues have been resolved and

    reported regularly through the report with complementary findings as a result.

    Some of the greatest advances in the report are the load combinations to be used for

    the method for fatigue verification, how the dynamic factor and the magnification

    factor should be used and how the trainloads to be designed for each method for

    fatigue verification.

  • 262.
    Lind, Lucas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    REVIT – ETT BRA HJÄLPMEDEL VID KLIMATDEKLARATION?: EN UNDERSÖKNING OM KLIMATDEKLARATION KAN UNDERLÄTTAS AV REVIT2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to SMHI the largest contributing factor to globalwarming is the increased greenhouse gas emissions in theatmosphere. In year 2018 Boverket submitted a proposal for climatedeclaration on new buildings. In the Boverkets climatedeclaration, a building's climate impact is calculated in the formof carbon dioxide equivalents on the material included in thefoundation, building envelope and the non-load-bearing interiorwalls. The unit in the climate declaration is kg Co2e / kg m2where m2 is BTA for the building.The purpose of the theoretical study was to describe what impactthe climate declaration will have in the building industry. Thepurpose of the empirical study was to investigate whether Revit isa good tool for calculating a building climate impact with a focuson greenhouse gas emissions.The result of the theoretical study indicates that the Boverket'sproposal on climate declaration will not lead to changes in theclimate impact of buildings. The study also shows that there willbe changes in the project planning of buildings and increased timespent by participants as the Boverkets estimation of the timerequired for the climate declaration is approximately 180 hours.The result of the empirical study shows that Revit is a good toolfor climate declaration. The study was based on evaluating Revitby the categories easy-to-use, time-consuming and presentationoptions. This resulted in a SWOT analysis showing Revit'scapacity

  • 263.
    Lindblom, Ellen
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Almquist, Isabelle
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Data-Driven Predictions of Heating Energy Savings in Residential Buildings2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Along with the increasing use of intermittent electricity sources, such as wind and sun, comes a growing demand for user flexibility. This has paved the way for a new market of services that provide electricity customers with energy saving solutions. These include a variety of techniques ranging from sophisticated control of the customers’ home equipment to information on how to adjust their consumption behavior in order to save energy. This master thesis work contributes further to this field by investigating an additional incentive; predictions of future energy savings related to indoor temperature. Five different machine learning models have been tuned and used to predict monthly heating energy consumption for a given set of homes. The model tuning process and performance evaluation were performed using 10-fold cross validation. The best performing model was then used to predict how much heating energy each individual household could save by decreasing their indoor temperature by 1°C during the heating season. The highest prediction accuracy (of about 78%) is achieved with support vector regression (SVR), closely followed by neural networks (NN). The simpler regression models that have been implemented are, however, not far behind. According to the SVR model, the average household is expected to lower their heating energy consumption by approximately 3% if the indoor temperature is decreased by 1°C. 

  • 264.
    Lindman, Joel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Westerlund, Lina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    DIMENSIONERING AV KONSTRUKTIONER I ROBOT STRUCTURAL ANALYSIS 2019: Skillnader och likheter med FEM-Design2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The basis of this thesis was that Kåver & Mellin Uppsala wanted todetermine if they should train their employees in the software RobotStructural Analysis. The company had licenses for the program that theydid not use due to lack of experience. The purpose of the project wastherefore to examine how Robot is used for designing structures and tocompare its usefulness to its competitor FEM-Design. The comparison ofusefulness was made by designing an identical structure in bothprograms. The focus of the study was to compare three main areas,workflow, areas of use and calculation results. This was made for themost common construction elements that were limited to concrete slabs,concrete walls, steel columns and steel beams.The study proved the programs to be similar. Designing steel profilesis more efficient in Robot. Another advantage of Robot is that there isan official online help page and a useful online forum, that FEM-Designlacks. One significant disadvantage of Robot is that the calculationsfor concrete are made with outdated national standards for Eurocode.The disadvantage was crucial and led to the conclusion that Kåver &Mellin Uppsala should wait for updated standards before using theprogram fully but they could start using Robot for load calculationsand steel design.

  • 265.
    Lindqvist, Elias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Mäcs, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Värmestrålningssköldar som brandskydd av stålelement: En teoretisk undersökning2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In fire tests performed in Australia meant to examine the effectivity of sprinkler systems, a few simple heat radiation shields made of highly reflective materials were also tested. In the trials three identical steel columns were exposed to fire in an office building. One of those columns were shielded with a galvanized steel sheet, the second with an aluminized steel sheet while the third was left unprotected. Data from the trial shows that the temperature of the steel columns was measured to 580°C and 427°C for the protected columns and 1064°C for the unprotected. Despite the positive results hardly any further studies has been made on this subject, which have motivated this report.

    The main goal of this report is to, with the help of theoretical experiments, prove that heat radiation shields can be used as a fire protection system for steel profiles. By implementing the underlying theory of heat transfer into a program capable of calculating a certain material’s ability to protect a steel profile from radiant heat, the temperature of the profile could be estimated.

    Results show that in order to sufficiently protect a VKR 200x200x10 millimeter steel profile exposed to 30 minutes of fire, a 1 millimeter heat radiation shield made out of a material with no less than 80 percent heat reflectivity has to be used. The material must also contain its reflectivity during the entire period, have a high enough density and not melt at a temperature lower than 1000°C. 

  • 266.
    Lindroth, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Grönskande balkongkonstruktioner: Jämförande arkivstudie av balkongkonstruktioner anpassade för urban odling2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Urban agriculture is a current topic and this study examines the possibility of cultivating on balconies in the city. The study was performed at Uppsala University and examines, from a structural engineering perspective, how different existing balcony/terrace structures are affected by cultivation. A cultivation balcony defined in the study as a balcony/terrace which is specifically designed for cultivation. Three units of study have been selected according to this criterion. Four factors were examined, these were loads, moisture/water, economy and cultivation. The study was conducted by studying the detailed drawings and interviewing the people concerned.

     

    The results show that one of the constructions is to be recommended but that there is great potential for developments in the area. A construction that is almost detached from the facade, showed the best results. This structure showed little influence and the least possibility of damage as a result of cultivation. The study also shows that cultivation is possible on a, of the author defined, standard balcony.

    The study has shown that there are few examples of the cultivation balconies in the current situation. The study also provides a suggestion of a design and construction of a cultivation balcony where different elements of the examined structures combined. The study also suggests areas that should be studied further for a development in the field of cultivation of alternative venues.

  • 267.
    Lindskog, Lisa
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Planeringsunderlag för nyanläggning av fjärrvärmeledning: En sammanställning av genomförda projekt2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis is done in order to establish an efficient method for planning inconstruction projects. The need for adequate planning is derived from the frequentoccurrence of disruptions that severely displace the schedule. The method will enablethe outcome to be more in line with the initial estimates of cost and time and allow amore efficient implementation. The thesis work is done on behalf of Skanska Väg ochAnläggning, for the district of Örebro/Västmanland.

    The study demonstrates the difficulties present when planning construction projects,as all potential obstacles cannot be foreseen. The chosen projects for the datacollection were all district heating projects conducted by Skanska and the owner ofthe heating network in Örebro. Data was gathered to determine how the resourcedistribution and the extent of changes in an average project usually occur. Thereafterthe data was used to lay the foundation for the method. The compilation shows largevarieties between the projects and simultaneously indicates the difficulties presentwhen planning these types of projects. Both the difficulty of predicting unforeseenevents and the diversity of the projects complicates the planning of future projects.The compilation from this work will serve as a base for simplifying the planningprocess and subsequently enable a more efficient implementation.

  • 268.
    Lisspers, André
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Konstruktionsutvärdering och optimering av strögrep2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the optimization process for the pitchfork developed by the company Sverigegrepen. The work was done at the department of Applied Mechanics at Uppsala University. The project were handed by Ångström Materials Academy together with Sverigegrepen

    The work included a major prestudy of plastic construction, plastic materials, plastic injection and strength of materials. By applying the laws of beam theory, a mathematical expression could be provided, explaining the behaviour of the pitchforks teeth.

    By studying the pitchfork with tools such as 3D- CAD and FEA-simulations, an area where high concentrations of stress were found, an area known to have frequent issues with strength. From this data several concepts were created with an increased strength and a better distribution of stress.

    The plastic material was evaluated and tested to find the most valuable material characteristics. The provided information was used to isolate different functions in plastic materials, which is crucial for the pitchforks further functionality. 

  • 269.
    Litsfeldt, Gustav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Förbättrad planering av maskin- och verktygsflödet på byggarbetsplatsen2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Building a house or a road is a coordination of different suboperations. Each suboperation requires a skilled worker, material, machines and different tools. The purpose of this essay is to investigate what kind of support the supervisors areable to use when it comes to hiring the machines and tools. The most common support when planning the need is called a machine plan. The companies that provide machines and tools by hire will also be investigated to see what they have to offer for their customers.

    The gathered information comes from the websites of the companies but also through interview with three different supervisors. Literature about construction management have been used to define what a machine plan is. All three of the interviewed supervisors do the planning of machines and tools when planning the rest of a suboperation. This is usually done a couple of weeks in advance. None of the interviewed supervisors use machine plans and the reason might be that it’s more useful to use it when planning the need of excavators and other big machines that needs a driver.

    The result from this essay is that there are two areas where there’s room for improvement. The first one is about the problems when ordering online. According to the interviewees it doesn’t work optimally. They would like to use this function when they know exactly what they need. The second area is the how the current holding is presented to the customer. They would like to be able to do sorting in the list and have it be more interactive. 

  • 270.
    Liu, Chenjuan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Qiu, Zhen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Brant, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ma, Yue
    Northwestern Polytechnical University.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zhu, Jie-Fang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    A free standing Ru–TiC nanowire array/carbon textile cathode with enhanced stability for Li–O2 batteries2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, p. 23659-23668Article in journal (Refereed)
    Abstract [en]

    The instability of carbon cathode materials is one of the key problems that hinder the development of lithium–air/lithium–oxygen (Li–O2) batteries. In this contribution, a type of TiC-based cathode is developed as a suitable alternative to carbon based cathodes, and its stability with respect to its surface properties is investigated. Here, a free-standing TiC nanowire array cathode was in situ grown on a carbon textile, covering its exposed surface. The TiC nanowire array, via deposition with Ru nanoparticles, showed enhanced oxygen reduction/evolution activity and cyclability, compared to the one without Ru modification. The battery performance of the Li–O2cells with Ru–TiC was investigated by using in operando synchrotron radiation powder X-ray diffraction (SR-PXD) during a full cycle. With the aid of surface analysis, the role of the cathode substrate and surface modification is demonstrated. The presented results are a further step toward a wise design of stable cathodes for Li–O2 batteries.

  • 271.
    Lockner, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    ENERGI- OCH KOSTNADSEFFEKTIVAMATERIALVAL I VÄRMESYSTEM: En jämförelse av rörmaterial i vattenburna värmesystem2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis aims to compare differentpiping materials in heating systems interms of cost as well as to illustratethe impact of energy characteristics ofdifferent materials over its servicelife. The methods used for costcalculations regarding piping are alsoto be examined to highlight thedifferences between template basedcalculations and more carefully executedones. The work is delimited to discusspipes of steel, copper, plastics andcomposites. The aim is that the resultcan be compiled to illustrate the prosand cons of various materials whenevaluating investments.The main object of the survey is part ofa heating system in the office-block KVSommaren located in southern Stockholm.The configured piping system is designedwith the mentioned piping materials andis used to make up the data for flow andcost calculations. The differentmaterials are calculated in both aconventional manner with a supplementarycost for additional fittings and with amore accurate quantification of thecomponents. Both are then compared inorder to assess how they differ from oneanother. Supplier data and buildingproduct declarations are used fordetermining energy properties concerningproduction, transportation and recyclingopportunities.The study indicates that the moderncomposite material AluPEX results in alower investment cost and therefore isthe most appropriate material providedthat it maintains its function under theintended service life. It is also clearthat the methods used for costcalculations differ from each other andthat the template based calculations canbe avoided by rather simple means. Theeffects of emphasizing the differentenergy properties of the materials in acost calculation can be consideredsmall. However, it illustratesproperties which may eventually becomeof great importance.

  • 272.
    Louice, Kjellberg
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Hur kan kostnaden minskas för dörrmiljöer utan att försumma funktionen?2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The door and its surrounding, is an important part of all buildings. It often amount to a significant part of buildings total costs. The more demands of functions the largerdoes the costs grow.

    The purpose of this report is to analyze those demands and how to fulfill them.

    Another purpose is to examine of which reasons the cost grow and how to avoid it inthe best possible way. The study will be performed in collaboration with Bjerking AB. To define the demands a literature study will also be performed. The essential part however will be interviews with persons with different employment regarding doors. The literature study shows the demanding are very different depending on several aspects. Those could be such things as the number of people passing and how the building is meant to be used.

    The results of the interviews shows doors and their surroundings are very complicated. The reasons are many. One of them is that persons are limited to their own employment and don’t have the knowledge to see the full context. Increased communication is a solution to that problem among others.

    With increased knowledge it’s possible to select better and cheaper solutions. Such solutions is about both choosing products and planning buildings design.

    There seem to be possible to develop doors and its surroundings in several ways. The interviewed persons often mention the door closer as one product they would likedevelopment in. It’s important it closes hard enough but it makes the door heavy to open since both forces often are equal.

    The problem today in developing better products is to find a participant willing to paythe cost the development requires.

  • 273.
    Lucas, Jakobsson
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Alexander, Aspén
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Ombyggnation av operation gentemot alternativa byggmetoder: En konsekvensutredning för ombyggnad vid Löwenströmska sjukhuset2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Over the next few years, major investments in healthcare buildings is to be performed. Most surgical theaters are in need of technological upgrades as the technology is outdated. In most cases not only a refurbishment is performed but also an expansion. The basis for expansion, is due to a large increased number of patients, but also to the complexity of the refitment. Partly it's because evacuations are difficult to implement and the disturbance that occurs in conjunction with the refitment.

    Löwenströmska hospital undergoing a technical upgrad. The hospital has a relatively small operation department, and during the summer the business may be closed. Rebuilding in stages is done to rehabilitate the department technically. Work is underway for four summers and covers a total refurbishment of the premises. Although shutdown is possible, the project is still complex.

    The purpose of this study is to examine whether other construction methods than rebuilding had been of value to the surgical department at Löwenströmska hospital. The goal is to overlook the efficiency of production, reduce the complexity added through the conversion, and compare the methods economically. Methods that have been examined are a new construction of a department, new construction with partial conversion and modules. The work is also carried out to facilitate the choice of method for future projects.

    The basis of the work lies in discussions and interviews with persons involved in the project. And review of blueprints and technical specifications .

    The conclusion of this study is that depending on the chosen construction method various advantages is gained. Depending on the circumstances and opportunities provided , all results provide beneficial solutions. Therefore, all investigated methods individually reviewed for similar projects.

  • 274.
    Ludvig, Ohlström
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Joakim, Gunnarsson
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Extensiva gröna tak: En byggteknisk studie om takgenomföringar och de gröna takens problematik2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is made by students from the bachelor programme in construction engineering at Uppsala university and it covers different pass-through roofing methods on extensive green roofs. The report also examines which existing solutions need further development. Eighty percent of all leakage occurs where vertical and horizontal surfaces meet as in pass-through. Hence, well planned solutions are required that counteract the risk of leakage at critical section. In Sweden there are currently no standards, guidelines or certifications for extensive green roofs.

    The extensive green roof offers a delay of rainwater, but this attribute also causes problems such as an increased moisture load on the entire roof, but especially on pass-throughs. The report, consisting mainly of literature and interview studies, has investigated and assessed pass-through solutions. The report has resulted in improved solutions consisting of the fact that perforation should be raised above the surface of the superstructure to reduce the exposure to moisture. To reduce moisture load around pass-troughs, it is also recommended to construct a gravel layer and a boundary plate that prevents vegetation from spreading. The spreading of vegetation and the occurrence of undesired vegetation must also be counteracted by maintenance, which should be performed at least twice a year, spring and autumn.

    A well-known opinion in the field of construction is that extensive green roofs are not in need of root protection, but as the occurrence of unwanted vegetation may have undesirable effects on the roofing membrane of the green roof, the use of root protection is always advocated.

  • 275.
    Ludéen, Emma
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Nordin, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Optimal ljudnivå i bostäder: En undersökning om det är möjligt att maskera spolljud från wc med ventilationsljud2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A lot of people experience sound pollution in their home even though the demands for sound levels are met. The majority of new constructions does not only fulfill the basic requirements but also reach the higher classifications that are presented by the Swedish Standards Institute. Even though this is the case, people still make complaints about being disturbed by noise. Bjerking AB states that they require an inquiry if it is possible to mask the noise from a disturbing sound with a background sound. The study also investigates if it is possible to mask the noise even more with a filtered background sound. The thought behind the masking of the sound is to add a background sound that is able to cover the disturbing sound and therefore make it harder to perceive. A test environment has been created based on the question about the possibility of masking a flushing sound from a toilet with a background sound. Twelve test persons have participated in the test using a signal when they identified the disturbing sound during different test scenarios. The result showed that it was in most scenarios possible to mask the disturbing sound with background sound and even better with a filtered background sound. Continuous research is needed to create a more secure method that studies the possibility of masking flushing noise from a toilet. Other types of noise should also be studied to gain a broader picture if masking can be applied to mask noise in residencies.

  • 276.
    Lundberg, Bengt
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Collet, P.
    Centre de Physique Theorique.
    Optimal wave shape with respect to efficiency in percussive drilling with detachable drill bit2015In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 86, p. 179-187Article in journal (Refereed)
    Abstract [en]

    Abstract The problem of finding the optimal incident wave of given duration that maximizes the efficiency of conversion of wave energy into work in percussive drilling with detachable drill bit is considered. The drill rod is modelled as 1D linearly elastic and the drill bit as a rigid mass. The bit/rock interaction is described by a history-dependent force versus penetration relation with different constant slopes for primary loading and unloading/reloading. A functional expressing the dependence of the efficiency on the shape of an arbitrary incident wave of given duration is derived and maximized. For short incident waves, there is a weak influence of the bit mass on the optimal wave shape which is nearly rectangular. For longer incident waves, there is a strong influence of the bit mass on the optimal wave shape which significantly differs from rectangular. The efficiencies for optimal waves approach those for rectangular waves for short waves. For long waves they approach or assume values which are independent of wave duration but decrease with increasing bit mass. Relative to commonly-used rectangular waves significant increase in efficiency can be achieved through optimization of the wave shape if the wave is not too short. Optimal incident waves can be realized accurately, e.g., by piezoelectric means.

  • 277.
    Lundberg, Bengt
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Collet, P.
    Optimal wave with respect to efficiency in percussive drilling with integral drill steel2010In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 37, no 8, p. 901-906Article in journal (Refereed)
    Abstract [en]

    The problem considered is that of finding the optimum wave of given finite duration that maximizes the efficiency of conversion of wave energy into work in percussive drilling with integral drill steel (drill rod with integrated bit). A 10 model is used for the drill rod, and the bit-rock interaction is represented by a piecewise linear force versus penetration relation with different penetration resistances for primary loading and for unloading/reloading. A functional expressing the dependence of the efficiency on the incident wave is derived and maximized. The optimal incident wave has exponential shape with time constant for the growth rate equal to the characteristic response time of the percussive drill system, including the rock. The maximal efficiency increases monotonously with the duration of the optimal wave. It approaches zero for very short waves and unity for very long waves. Optimal waves of short duration are close to rectangular while those of long duration approach the semi-infinite exponential wave derived by Long in the 1960s. Optimal waves of medium or longer duration give significantly higher efficiencies than commonly used rectangular waves of the same duration.

  • 278.
    Lundberg, Bengt
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Huo, J.
    Sandvik Min & Rock Technol, R&D Dept Min Tools, SE-81181 Sandviken, Sweden..
    Biconvex versus bilinear force-penetration relationship in percussive drilling of rock2017In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 100, p. 7-12Article in journal (Refereed)
    Abstract [en]

    Because of variability of the force vs. penetration relationship (FPR) from one blow to another in percussive drilling, and difficulty to predict FPRs under such conditions, use is commonly made of simple FPR models, such as the bilinear one defined by its loading/unloading slopes. Here a biconvex model with an added parameter representing convexity is considered. One aim is to study the effect of convexity on maximal penetration, maximal force and efficiency. Another is to assess, with the biconvex FPR as an example, how well a bilinear FPR can be used to approximate one that is nonlinear. A simple percussive top-hammer drill model is considered, comprising a hammer, a drill rod and a bit with the same characteristic impedance. The maximal penetration is found to decrease and the maximal force to increase with increasing convexity. The efficiency has a maximum for a finite hammer length (incident wave duration), and the highest maximal efficiency is obtained for a linear FPR With increasing convexity, the maximal efficiency decreases and occurs for shorter hammers (incident waves). The bilinear approximation of a biconvex FPR accurately predicts the position of the maximum in efficiency, even for large convexity, but somewhat overestimates its height and width.

  • 279.
    Lundgren, Pär
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Icke-linjära modelleringsteknikerav förspänd betongkonstruktion: Reaktorinneslutningen på Forsmark 32012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A new material model, for the FE-program ADINA, has been verified against twoexperiments. One unreinforced concrete beam and one reinforced concrete beam.The model, DF-concrete, has the possibility to estimate true concrete. However theresults indicate that in order to be sure that the estimations are true, there ought tobe data from the true concrete to verify against.

    Two FE-models have simulated the behavior of a ring-shaped part of the nuclearcontainment vessel. The results from the first, frictionless, model agree with similarsimulations and hand calculations for high pressures in the containment vessel. Thesimulations of the nuclear containment vessel show cracking in the concrete after10-11 bars of over pressurization. For low pressurizations the results differ from thereference simulation. The reason is most likely the lack of friction.

    The model with friction included cannot give correct results since the simulations failto represent the true friction between tendons and concrete. However the model issimpler and will probably in a functioning state give more accurate results comparedto the frictionless model.

  • 280.
    Lundin, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Lundin, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Byggdamm: Vad krävs för att minimera spridningen på ROT-projekt under produktionsskedet2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Dust that arises during the construction process is called “construction dust”.

    People who are exposed for construction dust for a long period of time are at

    risk to develop several forms of lung problems, allergies and cancer. Today

    construction dust is a huge problem during the production in Skanska´s

    renovation projects. Every day workers are exposed of the unhealthy

    construction dust and it can cause lung problems and diseases after 10-30

    years. This is a problem that must be taken into account to obtain a better

    working environment on Skanska´s building sites.

    Skanska Sweden AB has given two students the task to investigate possible

    problems about the spreading of construction dust. The students have made

    a literature study in construction wood- and quartz dust to try to solve this

    question. To obtain a reality-based approach of the problem, an

    observational study was performed on several construction sites as well as

    interviewing workers and officials.

    It has become clear that the problem is first and foremost based on a lack of

    knowledge about construction dust and the many risks that it causes. Based

    on the information and analyzes, a working method has been made called

    Kort Information Säkerhet (KIS). This presentation bases has been done to

    raise awareness and provide further knowledge of construction dust. The

    information will be carried out by Skanska officials to share the new

    information to Skanska’s employ’s.

  • 281.
    Lönnerholm, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    ENERGIANVÄNDING PÅ BYGGARBETSPLATSER: Analys av införandet av energieffektiva bygg­etableringar2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is the final step in the Bachelor of Science program in Building Construction Engineering, Department of Engineering Sciences, Uppsala University.

    The purpose of this study is to highlight the difficulties and possibilities that could involve the introduction of new energy efficient technologies and changing work around this technology. This study focuses on energy use at a construction site or other temporary workplace where so-called portacabins are in place to address the need for temporary facilities.

    The method for obtaining knowledge on the subject was mainly interviews with site managers working in Svevia AB's various activities. In conjunction with the interviews I visited construction sites and portacabins if it was possible.

    My most important suggestion to Svevia AB concerns a better organization in order to make poratacabins more efficient on energy and costs. The company should also evaluate and monitor the energy efficient portacabins that are in operation.

    Expected energy savings of new technology may not materialize if there are gaps in information, education, technical services and technical maintenance. It is very important to utilize the experiences of new technology. The experience should be used for the design of training, information and service schedules.

  • 282. Madsen, Bo
    et al.
    Gamstedt, E. KristoferUppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Cellulose fibers and their potential for reinforcement in composites2011Conference proceedings (editor) (Refereed)
  • 283.
    Madsen, Bo
    et al.
    Technical University of Denmark.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Wood vs. plant fibers: Similarities and differences in composite applications2013In: Advances in Materials Science and Engineering, ISSN 1687-8434, E-ISSN 1687-8442, Vol. 2013Article in journal (Refereed)
  • 284. Madsen, Bo
    et al.
    Gamstedt, Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Wood versus Plant Fibers: Similarities and Differences in Composite Applications2013In: Advances in Materials Science and Engineering, ISSN 1687-8434, E-ISSN 1687-8442, p. 564346-Article, review/survey (Refereed)
    Abstract [en]

    The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates in parallel wood fibers and plant fibers to highlight their similarities and differences regarding their use as reinforcement in composites and to enablemutual transfer of knowledge and technology between the two research fields. The paper gives an introduction to the morphology, chemistry, and ultrastructure of the fibers, the modeling of the mechanical properties of the fibers, the fiber preforms available for manufacturing of composites, the typical mechanical properties of the composites, the modeling of the mechanical properties with focus on composites having a random fiber orientation and a non-negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed.

  • 285.
    Magnusson, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Användning av Klimatverktyg2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A big part of Sweden's carbon dioxide is emitted by the construction business. Skanska is one of the biggest construction contractors in the world with an ambitious sustainability agenda.

    The purpose of this thesis is to evaluate how Skanska Väg och Anläggning, region Mellansverige, distrikt Uppsala uses Skanska’s own tools to reduce their climate impact from a project. The two tools that were carefully studied were Skanska’s color palette and a module to calculate the carbon emissions from a project.

    Data were collected through literature and interviews among Skanska employees. Collected data was analyzed by the author of the thesis and is presented in the last part of the report.

    Employees interviewed were positive towards the use of the tools. But the way the tools presented their information could be improved. Mainly by simplifying the information so it effortless could be applied by personnel running the construction.

     

  • 286.
    Malmberg, Filip
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Centre for Image Analysis. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Lindblad, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Centre for Image Analysis. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Östlund, Catherine
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Centre for Image Analysis. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Almgren, Karin
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Measurement of fibre–fibre contact in three-dimensional images of fibrous materials obtained from X-ray synchrotron microtomography2011In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 637, no 1, p. 143-148Article in journal (Refereed)
  • 287. Malmberg, Filip
    et al.
    Lindblad, Joakim
    Östlund, Catherine
    Almgren, Karin M.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Measurement of fibre–fibre contact in three-dimensional images of fibrous materials obtained from X-ray synchrotron microtomography2011In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 637, no 1, p. 143-148Article in journal (Refereed)
    Abstract
  • 288.
    Malmström, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Olmenius, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Arbetsmiljö: Identifiering och åtgärder kring användningen av den personliga skyddsutrustningen2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report reflects the work environment and personal safety atNCC's job site Sky City Office One (SCOO). The purpose was toexamine the workers usage of the personal safety equipment. Thisstudy also aims to identify whether there are any so-calledsuccess factors that could be linked to SCOO. Furthermore, thereport examines if there are any elements that NCC could improve.This study also aspires to give an improved understanding of thework environment at the job site.The chosen method consisted of surveys and interviews with themanagement staff and the Swedish and Latvian workers. The resultswere analyzed according to relevant literature and then presented.In a second step, the identified success factors were listed. Thereport concludes with suggestions for improvement.The result of this study demonstrates a difference between theSwedish personnel hired by NCC and the Latvian workers.Differences were mainly ascertained in the workers attitudetowards the work environment but also in the question of whetherlanguage barriers exist between the workers.The identified success factors were mainly good leadership, thehigh experience level amongst the workforce and NCC's concept of"Time out" which is aimed at the improvement of the workersattitude towards potentially dangerous situations.In the final chapter, improvements of the NCC worksite aresuggested and a future recommendation for improved safety of NCCworksites is given.

  • 289.
    Marais, Andrew
    et al.
    Dept of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH, Stockholm.
    Kochumalayil, Joby J.
    Dept of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH, Stockholm.
    Nilsson, Camilla
    Dept of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH, Stockholm.
    Fogelström, Linda
    Dept of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH, Stockholm.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Toward an alternative compatibilizer for PLA/cellulose composites: Grafting of xyloglucan with PLA2012In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 89, no 4, p. 1038-1043Article in journal (Refereed)
    Abstract [en]

    Poly(L-lactic acid) (PLLA) chains were grafted on xyloglucan substrates via ring-opening polymerization of the L-Iactide monomer. Different parameters such as the nature of the substrate (native or modified xyloglucan) and the substrate/monomer ratios were varied in the synthesis to achieve different lengths of the grafted chains. A range of experimental techniques including infrared spectroscopy and nuclear magnetic resonance were used to characterize the final product. Thermal analysis showed that the glass transition temperature of xyloglucan was decreased from 252 degrees C to 216 degrees C following the grafting of PLLA. The grafting of less hydrophilic chains from xyloglucan also affected the interaction with water: the PLEA-grafted xyloglucan was insoluble in water and the moisture uptake could be decreased by about 30%. Xyloglucan adsorbs strongly to cellulose; therefore such a graft copolymer may improve the compatibility between cellulose fibers and PLLA. The PLEA-grafted xyloglucan may be useful as a novel compatibilizer in fiber-reinforced PLEA composites. 

  • 290. Marais, Andrew
    et al.
    Magnusson, Mikael S.
    Joffre, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Wernersson, Erik L. G.
    Wagberg, Lars
    New insights into the mechanisms behind the strengthening of lignocellulosic fibrous networks with polyamines2014In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, no 6, p. 3941-3950Article in journal (Refereed)
    Abstract [en]

    Polyelectrolytes have been used extensively in the papermaking industry for various purposes. Although recent studies have shown that polyamines can be efficient dry-strength additives, the mechanism governing the strength enhancement of paper materials following the adsorption of polyamines onto pulp fibres is still not well understood. In this study, the effect of the adsorption of polyallylamine hydrochloride (PAH) onto the surface of unbleached kraft pulp fibres was investigated on both the fibre and the network scale. Isolated fibre crosses were mechanically tested to evaluate the impact of the chemical additive on the interfibre joint strength on the microscopic scale and the effect was compared with that previously observed on the paper sheet scale. X-ray microtomography was used to understand structural changes in the fibrous network following the adsorption of a polyamine such as PAH. Using image analysis methods, it was possible to determine the number of interfibre contacts (or joints) per unit length of fibre as well as the average interfibre joint contact area. The results showed that the median interfibre joint strength increased by 18 % upon adsorption of PAH. This can be achieved both by a larger molecular contact area in the contact zones and by a stronger molecular adhesion. The addition of the polymer also increased the number of efficient interfibre contacts per sheet volume. This combination of effects is the reason why polyamines such as PAH can increase the dry tensile strength of paper materials.

  • 291.