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  • 1.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Nonparametric structural damage detection algorithm for ambient vibration response: utilizing artificial neural networks and self-organizing maps2016Inngår i: Journal of Architectural Engineering, ISSN 1076-0431, E-ISSN 1943-5568, Vol. 22, nr 2Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study presentes a new nonparametric structural damage detection algorithm that integrates self-organizing maps with a pattern-recognition neural network to quantify and locate structural damage. In this algorithm, self-organizing maps are used to extract a number of damage indices from the ambient vibration response of the monitored structure. The presented study is unique because it demonstrates the development of a nonparametric vibration-based damage detection algorithm that utilizes self-organizing maps to extract meaningful damage indices from ambient vibration signals in the time domain. The ability of the algorithm to identify damage was demonstrated analytically using a finite-element model of a hot-rolled steel grid structure. The algorithm successfully located the structural damage under several damage cases, including damage resulting from local stiffness loss in members and damage resulting from changes in boundary conditions. A sensitivity study was also conducted to evaluate the effects of noise on the computed damage indices. The algorithm was proved to be successful even when the signals are noise-contaminated.

  • 2.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Do, Ngoan Tien
    University of Alberta, Canada.
    Gul, Mustafa
    University of Alberta, Canada.
    Celik, Ozan
    University of Central Florida, USA.
    Catbas, Necati
    University of Central Florida, USA.
    Quantification of Structural Damage with Self-Organizing Maps2016Inngår i: Structural Health Monitoring, Damage Detection & Mechatronics: Proceedings of the 34th IMAC, A Conference and Exposition on Structural Dynamics 2016, Springer, 2016, Vol. 7, s. 47-57Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    One of the main tasks in structural health monitoring process is to create reliable algorithms that are capable of translating the measured response into meaningful information reflecting the actual condition of the monitored structure. The authors have recently introduced a novel unsupervised vibration-based damage detection algorithm that utilizes self-organizing maps to quantify structural damage and assess the overall condition of structures. Previously, this algorithm had been tested using the experimental data of Phase II Experimental Benchmark Problem of Structural Health Monitoring, introduced by the IASC (International Association for Structural Control) and ASCE (American Society of Civil Engineers). In this paper, the ability of this algorithm to quantify structural damage is tested analytically using an experimentally validated finite element model of a laboratory structure constructed at Qatar University.

  • 3.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Active vibration control of flexible cantilever plates using piezoelectric materials and artificial neural networks2016Inngår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 363, s. 33-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The study presented in this paper introduces a new intelligent methodology to mitigate the vibration response of flexible cantilever plates. The use of the piezoelectric sensor/actuator pairs for active control of plates is discussed. An intelligent neural network based controller is designed to control the optimal voltage applied on the piezoelectric patches. The control technique utilizes a neurocontroller along with a Kalman Filter to compute the appropriate actuator command. The neurocontroller is trained based on an algorithm that incorporates a set of emulator neural networks which are also trained to predict the future response of the cantilever plate. Then, the neurocontroller is evaluated by comparing the uncontrolled and controlled responses under several types of dynamic excitations. It is observed that the neurocontroller reduced the vibration response of the flexible cantilever plate significantly; the results demonstrated the success and robustness of the neurocontroller independent of the type and distribution of the excitation force.

  • 4.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Genetic algorithm use for internally resonating lattice optimization: case of a beam-like metastructure2016Inngår i: Dynamics of Civil Structures: Proceedings of the 34th IMAC, A Conference and Exposition on Structural Dynamics 2016 / [ed] Shamim Pakzad, Caicedo Juan, Springer, 2016, s. 289-295Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Metamaterial inspired structures, or metastructures, are structural members that incorporate periodic or non-periodic inserts. Recently, a new class of metastructures has been introduced which feature chiral lattice inserts. It was found that this type of inserts has frequency bandgaps which can be tuned by altering the geometry of the chiral lattice. Previous studies have shown that inserting non-periodic chiral lattices inside a beam-like structure results in efficient vibration attenuation at low frequencies. In the study presented in this paper, a genetic algorithm based optimization technique is developed to automatically generate chiral lattices which are tuned to suppress vibration in a flexible beam-like structure. Several parameters are incorporated in the optimization process such as the radius of circular nodes and characteristic angle as well as the spacing and distribution of circular inserts. The efficiency of the …

  • 5.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Optimization of chiral lattice based metastructures for broadband vibration suppression using genetic algorithms2016Inngår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 369, s. 50-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the major challenges in civil, mechanical, and aerospace engineering is to develop vibration suppression systems with high efficiency and low cost. Recent studies have shown that high damping performance at broadband frequencies can be achieved by incorporating periodic inserts with tunable dynamic properties as internal resonators in structural systems. Structures featuring these kinds of inserts are referred to as metamaterials inspired structures or metastructures. Chiral lattice inserts exhibit unique characteristics such as frequency bandgaps which can be tuned by varying the parameters that define the lattice topology. Recent analytical and experimental investigations have shown that broadband vibration attenuation can be achieved by including chiral lattices as internal resonators in beam-like structures. However, these studies have suggested that the performance of chiral lattice inserts can be maximized by utilizing an efficient optimization technique to obtain the optimal topology of the inserted lattice. In this study, an automated optimization procedure based on a genetic algorithm is applied to obtain the optimal set of parameters that will result in chiral lattice inserts tuned properly to reduce the global vibration levels of a finite-sized beam. Genetic algorithms are considered in this study due to their capability of dealing with complex and insufficiently understood optimization problems. In the optimization process, the basic parameters that govern the geometry of periodic chiral lattices including the number of circular nodes, the thickness of the ligaments, and the characteristic angle are considered. Additionally, a new set of parameters is introduced to enable the optimization process to explore non-periodic chiral designs. Numerical simulations are carried out to demonstrate the efficiency of the optimization process.

  • 6.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Boashash, Boualem
    Qatar University, Qatar; The University of Queensland, Herston, Australia.
    Sodano, Henry
    University of Michigan, USA.
    Inman, Daniel
    University of Michigan, USA.
    1-D CNNs for structural damage detection: verification on a structural health monitoring benchmark data2018Inngår i: Neurocomputing, ISSN 0925-2312, E-ISSN 1872-8286, Vol. 275, s. 1308-1317Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Structural damage detection has been an interdisciplinary area of interest for various engineering fields. While the available damage detection methods have been in the process of adapting machine learning concepts, most machine learning based methods extract “hand-crafted” features which are fixed and manually selected in advance. Their performance varies significantly among various patterns of data depending on the particular structure under analysis. Convolutional neural networks (CNNs), on the other hand, can fuse and simultaneously optimize two major sets of an assessment task (feature extraction and classification) into a single learning block during the training phase. This ability not only provides an improved classification performance but also yields a superior computational efficiency. 1D CNNs have recently achieved state-of-the-art performance in vibration-based structural damage detection; however, it has been reported that the training of the CNNs requires significant amount of measurements especially in large structures. In order to overcome this limitation, this paper presents an enhanced CNN-based approach that requires only two measurement sets regardless of the size of the structure. This approach is verified using the experimental data of the Phase II benchmark problem of structural health monitoring which had been introduced by IASC-ASCE Structural Health Monitoring Task Group. As a result, it is shown that the enhanced CNN-based approach successfully estimated the actual amount of damage for the nine damage scenarios of the benchmark study.

  • 7.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Gabbouj, Moncef
    Tampere University of Technology, Finland.
    Inman, Daniel
    University of Michigan, USA.
    Real-time vibration-based structural damage detection using one-dimensional convolutional neural networks2017Inngår i: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 388, s. 154-170Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Structural health monitoring (SHM) and vibration-based structural damage detection have been a continuous interest for civil, mechanical and aerospace engineers over the decades. Early and meticulous damage detection has always been one of the principal objectives of SHM applications. The performance of a classical damage detection system predominantly depends on the choice of the features and the classifier. While the fixed and hand-crafted features may either be a sub-optimal choice for a particular structure or fail to achieve the same level of performance on another structure, they usually require a large computation power which may hinder their usage for real-time structural damage detection. This paper presents a novel, fast and accurate structural damage detection system using 1D Convolutional Neural Networks (CNNs) that has an inherent adaptive design to fuse both feature extraction and classification blocks into a single and compact learning body. The proposed method performs vibration-based damage detection and localization of the damage in real-time. The advantage of this approach is its ability to extract optimal damage-sensitive features automatically from the raw acceleration signals. Large-scale experiments conducted on a grandstand simulator revealed an outstanding performance and verified the computational efficiency of the proposed real-time damage detection method.

  • 8.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Kiranyaz, Serkan
    Qatar University, Qatar.
    Inman, Daniel
    University of Michigan, USA.
    Optimization of linear zigzag insert metastructures for low-frequency vibration attenuation using genetic algorithms2017Inngår i: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 84, nr Part A, s. 625-641Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vibration suppression remains a crucial issue in the design of structures and machines. Recent studies have shown that with the use of metamaterial inspired structures (or metastructures), considerable vibration attenuation can be achieved. Optimization of the internal geometry of metastructures maximizes the suppression performance. Zigzag inserts have been reported to be efficient for vibration attenuation. It has also been reported that the geometric parameters of the inserts affect the vibration suppression performance in a complex manner. In an attempt to find out the most efficient parameters, an optimization study has been conducted on the linear zigzag inserts and is presented here. The research reported in this paper aims at developing an automated method for determining the geometry of zigzag inserts through optimization. This genetic algorithm based optimization process searches for optimal zigzag designs which are properly tuned to suppress vibrations when inserted in a specific host structure (cantilever beam). The inserts adopted in this study consist of a cantilever zigzag structure with a mass attached to its unsupported tip. Numerical simulations are carried out to demonstrate the efficiency of the proposed zigzag optimization approach.

  • 9.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Hussein, Mohammed
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Davis, Brad
    University of Kentucky, USA.
    Reynolds, Paul
    University of Exeter, UK.
    A novel video-vibration monitoring system for walking pattern identification on floors2020Inngår i: Advances in Engineering Software, ISSN 0965-9978, E-ISSN 1873-5339, Vol. 139, artikkel-id 102710Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Walking-induced loads on office floors can generate unwanted vibrations. The current multi-person loading models are limited since they do not take into account nondeterministic factors such as pacing rates, walking paths, obstacles in walking paths, busyness of floors, stride lengths, and interactions among the occupants. This study proposes a novel video-vibration monitoring system to investigate the complex human walking patterns on floors. The system is capable of capturing occupant movements on the floor with cameras, and extracting walking trajectories using image processing techniques. To demonstrate its capabilities, the system was installed on a real office floor and resulting trajectories were statistically analyzed to identify the actual walking patterns, paths, pacing rates, and busyness of the floor with respect to time. The correlation between the vibration levels measured by the wireless sensors and the trajectories extracted from the video recordings were also investigated. The results showed that the proposed video-vibration monitoring system has strong potential to be used in training data-driven crowd models, which can be used in future studies to generate realistic multi-person loading scenarios.

  • 10.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Younis, Adel
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Catbas, Necati
    University of Central Florida, USA.
    Gul, Mustafa
    University of Central Florida, USA.
    Celik, Ozan
    University of Central Florida, USA.
    Zhang, Haiyang
    University of Alberta, USA.
    Dynamic Testing of a Laboratory Stadium Structure2016Inngår i: Geotechnical and Structural Engineering Congress 2016, American Society of Civil Engineers (ASCE), 2016, s. 1719-1728Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Studies with large physical models are a vital link between the theoretical work and field applications provided that these models are designed to represent real structures where various types and levels of uncertainties can be incorporated. While comprehensive analytical and laboratory joint studies are ongoing at Qatar University, University of Central Florida and University of Alberta, this paper presents the initial findings of dynamic testing at Qatar University. A laboratory stadium structure (grandstand simulator) has been constructed at Qatar University. Capable of housing thirty spectators, Qatar University grandstand simulator is arguably the largest laboratory stadium in the world. The structure is designed in a way that several different structural configurations can be tested in laboratory conditions to enable researchers to test newly developed damage detection algorithms. The study presented in this paper covers the finite element modeling and modal testing of the test structure.

  • 11.
    Abdula, Sham
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Oksman, Dan
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Attefallshus som komplementbostadshus: Drömhus eller mardröm?2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den 2 juli 2014 blev det enligt lag tillåtet för en- och tvåbostadshusägare att uppföra en bygglovsbefriad komplementbyggnad på max 25 kvadratmeter på den egna fastigheten. Rapporten undersöker vilket genomslag lagändringen har haft i Stor-Stockholm, Stor-Göteborg och Stor-Malmö. Undersökningen visar att lagändringen ännu inte har haft något stort genomslag. I rapporten undersöks även en utvald del av marknadsaktörers utbud av attefallshus avsett som komplementbostadshus. 

    Ett attefallshus utformas med miljövänligt hållbara material och inspireras av Vitruvius tre principer för god arkitektur. Huset konstrueras med avsikt att uppfylla kraven som ställs i PBL, PBF, BBR och EKS. Målet med de framtagna bygghandlingarna är att få startbesked från byggnadsnämnden i Växjö. 

  • 12.
    Addassi, Mouadh
    et al.
    Technical University of Denmark, Denmark.
    Johannesson, Björn
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Reactive mass transport in concrete including for gaseous constituents using a two-phase moisture transport approach2020Inngår i: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 232, s. 1-14, artikkel-id 117148Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article presents the further development of a tool for multi-phase reactive mass transport modelingfor durability estimation of cement-based materials, by the addition of the gas phase, adopting a trulyseparate two-phase moisture transport approach. The governing system of equations are based on phys-ically sound hybrid mixture based version of the Poisson-Nernst-Planck system of equations includinggaseous transport in the air-filled space, ionic transport in the liquid phase, electro-migration of ionicspecies, a two-phase moisture transport model, and sorption. The addition of the gas phase and thetwo-phase moisture description enables the user of the model to investigate individual and combinedeffects of different degradation processes in unsaturated systems. The altering of hydrated cement underthree different environments were studied representing an accelerated carbonation environment, a sub-merged marine environment and a cyclic drying-wetting zone in a marine environment, to illustratesome of the model’s capabilities.

  • 13.
    Addassi, Mouadh
    et al.
    Technical University of Denmark, Denmark.
    Johannesson, Björn
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Wadsö, Lars
    Lund University.
    Inverse analyses of effective diffusion parameters relevant for a two-phase moisture model of cementitious materials2018Inngår i: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 106, s. 117-129Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here we present an inverse analyses approach to determining the two-phase moisture transport properties re-levant to concrete durability modeling. The purposed moisture transport model was based on a continuumapproach with two truly separate equations for the liquid and gas phase being connected by the sorption ki-netics. The moisture properties of ten binder-systems containingfly ash, calcined clay, burnt shale and graymicro-filler, were investigated experimentally. The experiments used were, (i) sorption test (moisturefixation),(ii) cup test in two different relative humidity intervals, (iii) drying test, and, (iv) capillary suction test. Masschange over time, as obtained from the drying test, the two different cup test intervals and the capillary suctiontest, was used to obtain the effective diffusion parameters using the proposed inverse analyses approach. Themoisture properties obtained with the proposed inverse analyses method provide a good description of the testperiod for the ten different binder-systems.

  • 14.
    Ahlgren, Sara
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Lindström, Jenny
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Ekonomi, kunskap och kommunikation: – Avgörande för den estetiska kvaliteten vid nyproduktion av bostäder2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det finns indikationer på att arkitekturen i Sverige upplevs som mer och mer enformig med avsaknad av estetiska kvaliteter. Arkitekter får bära ansvaret för påståendet, men själva menar de att de fråntagits sin ställning i byggprocessen där de byts ut under pågående projekt, underordnade ekonomiska intressen.

    Målet med arbetet var att ta reda på vad som händer med en byggnads estetiska kvaliteter när arkitekten byts ut samt vad som ligger bakom att bytet sker. En jämförelse mellan två objekt gjordes, ett där arkitekten varit med under hela processen och ett där arkitekten blivit utbytt. Studien utfördes genom faktainsamling från litteratur, observationer och intervjuer.

    Resultatet visar att viljan att bygga vackert med estetiska kvaliteter är starkt kopplat till beställarens ambitionsnivå. Det sammantagna resultatet visar dock på att estetiska värden underordnas ekonomi i byggprocessen. Vidare har det framkommit under arbetets gång att det råder kunskapsbrist och kommunikationssvårigheter mellan aktörer i byggbranschen, framförallt mellan arkitekt och entreprenör.

  • 15.
    Ahmad, Elaf
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Hultgren, Mathilda
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Möjligheter för visualisering i presentation av småhus2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Rapporten behandlar hur husleverantörer kan utveckla presentationsmaterial. De materialen som visas är olika husmodeller från företagen och behandlar bakgrundsvyer samt förbättringar i digital media. Företaget som ligger till grund för rapporten är Trivselhus, och undersökningarna i rapporten är baserade på aktörer i anknytning till företaget. Resultatet kan även tillämpas hos andra husleverantörer.

    Visualisering handlar om hur människan tar till sig den informationen som ges. Den används för att underlätta förståelsen för komplicerade bilder och idéer som visas för kunder. Visualisering möjliggör att bearbetade bilder kan kopplas samman med slutresultatet som presenteras.

    Informationen som kommer genom visualisering kan fås genom människans fem sinnen syn, lukt, hörsel, smak och känsel. Denna studie lägger fokus på den synliga aspekten till visualisering och hur företag kan använda den för att förstärka sin kundkrets.

    Resultatet ger exempel på visualisering som husleverantörer kan tillämpa i verksamheten. Det behandlar bland annat utveckling av hemsidor och gemensamma plattformar som kund och säljare båda kan arbeta i. Andra framtidsförslag som presenteras är en utveckling av visningshus samt producering av miniatyrhus. Detta för att ge kunden en bättre visualisering och därmed en större insyn i hur det färdiga huset är utformat och kommer fungera i verkligheten.

  • 16.
    Akter, Shaheda T.
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Bader, Thomas K.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Enquist, Bertil
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Failure envelope for interaction of stresses perpendicular to the grain with rolling shear stress in wood2018Inngår i: 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11 – 15 June 2018, Glasgow, UK, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The orthotropic material property in combination with ductility in compression, brittleness in shear and tension, very low shear modulus in radial-tangential (RT) plane etc. requires anisotropic stress failure criteria, as well as their evolution with increasing strains. Three- dimensional failure criteria have been proposed for this purpose, but their validation in the RT plane with interaction of rolling shear stresses has attracted less attention. Corresponding stress interactions are however important for modelling of engineered wood-based products under compression perpendicular to the grain when taking into account influence of the annual ring structure.

    The work aims at defining failure envelopes for stresses perpendicular to the grain with rolling shear stress interaction based on experimental investigations performed on Norway spruce. The experimental set-up was realized in a biaxial testing frame and consisted of stiff steel plates to transfer load from the testing machine to wood specimen. Mechanical grips prevented rotation and uplifting of the specimen in case of pure shear and tensile loading, respectively. In addition to conventional linear variable differential transformers, a digital image correlation system was used to measure strain fields on the surface of wood specimens and steel plates. Measurements of dog-bone shaped specimens were carried out along different stress interaction paths by displacement controlled loading.

    The experimental dataset was then compared with commonly used phenomenological failure criteria, namely Tsai-Hill, Tsai-Wu [1], Norris [2] and Hoffman, as well as with regression equations from previous works [3].Experiments revealed that the stress-strain relationship under compression, shear, and biaxial loading differs in radial and tangential directions. None of the three-dimensional stress failure criteria provided good prediction of experiments under compression and rolling shear, but experimental data was closer to the regression equation proposed in [3].

  • 17.
    Akter, Shaheda T.
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Bader, Thomas K.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Serrano, Erik
    Lund University, Sweden.
    Modeling of wood under combination of normal stresses with rolling shear stress2019Inngår i: Presented at CompWood 2019 - International Conference on Computational Methods in Wood Mechanics - from material properties to Timber Structures, Växjö, Sweden, June 17-19, 2019, Växjö, Sweden, 2019Konferansepaper (Fagfellevurdert)
  • 18.
    Akter, Shaheda T.
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Bader, Thomas K.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Serrano, Erik
    Lund University, Sweden.
    Modelling of wood under compression perpendicular to the grain with rolling shear in cross-laminated timber2019Inngår i: Presented at COMPLAS 2019 - XV International Conference on Computational Plasticity: Fundamentals and Applications, Barcelona, Spain, September 3-5, 2019, Barcelona, Spain: European Community on Computional Methods in Applied Sciences (ECCOMAS), 2019Konferansepaper (Fagfellevurdert)
  • 19.
    Al Jaafar, Jaafar
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Projektering av platsbyggd villa2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Sammanfattning

    Detta examensarbete är ett utformningsprojekt av en platsbyggd villa. Frågeställningen till

    projektet var hur man kan utforma en villa.

    Jag har undersökt vilka A-ritningar, K-ritningar samt statiska beräkningar som behövs för att

    producera en platsbyggd villa.

    Resultatet visar färdiga ritningar till bygghandlingar vilket betyder enplans villa med

    attraktiv/öppen planlösning och en stark byggnadsstil med tydliga inflytanden av funkisstil.

    Detta tydliggörs genom pulpettaken, och fasaden som är delvis liggande panel, delvis vit

    putsad.

    Yta: 153 kvm

    Antal rum: 6, varav sovrum: 3

  • 20.
    Al Jaafar, Jaafar
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Projektering av platsbyggd villa2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Abstract (in English)

    "This thesis work is a design project of an on-site construcktions. The issue addressed by the project was how to

    devise and design an detached house

    I have examined which architecture-drawings, construcktion-drawings and static calculations are needed to

    produce an on-site construcktions detached house.

    The result is presented in the finished drawings for the construction documents, which show a one-storey

    detached house with an attractive/accessible construction plan. It uses the combination of a strong style of

    architecture and a clear influence of functional design. This is clarified by the bench ceilings, and the facade,

    which is partly laying panel, partly white trimmed.

    Size: 153 square meters

    Number of rooms: 6, where of 3 are bedrooms."

  • 21.
    Al-anbagi, Ali
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Khalil, Dani
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Utformning avlandningsbanors överbyggnad med hänsyn till slitlagrets bärförmåga2020Independent thesis Basic level (professional degree), 180 hpOppgave
    Abstract [en]

    n this study, the design of the runway structure of the runways is studied in order tocompare different material compositions in the pavement. This is done with the helpof a survey, the program FAARFIELD and peer reviewed studies. Generally, thereare two different types of road structures in an airfield, rigid and flexible (concreteand asphalt). The result obtained shows the difference between the differentdimensions and the material content of the different types of road structures, whenthey are loaded with either heavy or light aircraft models. These results are based ona design period that has been selected for 20 years. In contrast, the stiffness of theconcrete was much higher than the asphalt stiffness, which means that it is better touse concrete in large commercial airports. According to the CDF diagram (thediagram showing whether the structural design conditions are met), the damagecaused by the aircraft is approximately at the same location on the runway for bothsuperstructures, it also means that flexible superstructure maintenance needs to bedone more often, compared to rigid superstructures. The fact that the asphalt has alower modulus of elasticity than the concrete is also a reason why maintenance forflexible superstructures needs to be done more often. However, when the roadstructures became heavily loaded, the total demanding thickness for the rigid roadstructure is calculated to be 760 mm and for the flexible road structure 710 mm.

  • 22.
    Al-Ansari, Nabil
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Te Seng, Meng
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Studentbostäder i trä med Prefab-teknik2009Independent thesis Basic level (degree of Bachelor), 80 poäng / 120 hpOppgave
    Abstract [en]

    The Results of this thesis was the creation of two designed house variants with a module to

    all the apartments. In addition till the first module there are three other modules of

    apartments that can be put in the houses if it so needs. The house are volume prefabricated

    and are placed on site in a way that it create an enclosure of the area which faces against the

    nature and car parks also lies hidden behind these houses.

    For the actual structure, a cross beam was created to carry the floor above and it is support

    by all four walls. The structure between the first and the second floor has no "syll" but

    instead there are two differently alternative to linking the floors in order so that it will not

    move. The reason with this solution was that there will not be any subsidence when the

    forces from above are pressed down ward. The forces are instead directly down to the next

    timber frame system. This can happen when the real estate's owner might want to build

    more floors on the house than the present two floors house when there is no land to build

    and spaces are needed in the future.

  • 23.
    Albertsen, Henrik
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Lindberg, Amanda
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Lokalt omhändertagande av dagvatten på bostadsfastigheter2016Independent thesis Basic level (professional degree), 180 hpOppgave
    Abstract [sv]

    Ett behov finns av att fördröja dagvatten innan det släpps på det kommunala ledningsnätet för att minska flödestopparna och undvika överbelastning. Studien avser att ta fram en förenklad metod för val och utformning av LOD-metod som är anpassad för privata fastighetsägare.

    Ett flertal LOD-anläggningar samt förutsättningar kring dessa har undersökts. Studien har gett en grundläggande information och en beräkningsgång som har förenklats, är lätt att följa och som kan anpassas efter befintliga förutsättningar och önskemål. 

  • 24.
    Aldarwash, Mustafa
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Bajqinca, Alban
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Nybyggnation av badrum : Jämförelse mellan prefabricerat och platsbyggt ur ett ekonomiskt perspektiv2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med arbetet är att, genom en ekonomisk undersökning skapa underlag som visar vilket alternativ av produktionsmetoderna prefabricerat eller platsbyggt badrum som är att föredra vid en nybyggnation av vårdhem. 

    Resultatet visar att det platsbyggda badrummet ger en ökad totalt kostnad på 627457 kr vilket motsvarar 11,1 procent dyrare än det prefabricerade badrummet. 

  • 25.
    Aldén, Jonathan
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Pålsson, Kristian
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Robertson, Johan
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Krav och kvalitetssäkring av BIM-objekt inom projektering, produktion samt förvaltning2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den ökade användningen av BIM har ändrat villkoren inom byggsektorn. Arbetet syftar till att identifiera och definiera de krav och kvalitetssäkringar av BIM-objekt som finns inom projektering, produktion samt förvaltning. Avsaknad av en gemensam standard försvårar kravställning och kvalitetssäkring av BIM-objekt vilket har lett till vissa komplikationer, främst vid konvertering mellan olika programvaror.

    BIM är med sin potential med största sannolikhet en stor del av byggsektorns framtid. För att kunna ta nästa steg i utvecklingen måste en gemensam standard gällande krav och kvalitetssäkring utarbetas.

  • 26.
    Algabroun, Hatem
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    On the development of a maintenance approach for factory of the future implementing Industry 4.02017Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The objective of this thesis is to develop a maintenance approach that fulfills the requirements of Industry 4.0. It explores the role and importance of maintenance activities in today’s industry. Then, it develops the features and tasks required to be performed by maintenance to fulfill the demands of Industry 4.0. Finally, it develops a reference model to be used in designing maintenance system for Industry 4.0. To perform these studies, real data were collected and applied as well as a typical scenario was implemented.

    The results achieved in the papers of this thesis are 1) a mathematical representation and application of a model that identifies, analyses and prioritizes economic weakness in working areas related to production, 2) a model that analyses, identifies and prioritizes failures that impact the competitive advantages and profitability of companies, 3) characterization of a suitable maintenance technique for Industry 4.0 and 4) a reference model i.e. a framework, that could be utilized to develop a maintenance approach for Industry 4.0.

    The conclusion of this thesis confirms that maintenance has a significant impact on companies’ competitive advantages, other working areas and profitability. To achieve a suitable maintenance technique for Industry 4.0, this technique must be able to monitor, diagnose, prognosis, schedule, assist in execution and present the relevant information. In order to perform these tasks several features must be acquired, the most important features are to be: digitized, automated, intelligent, able to communicate with other systems for data gathering and monitoring, openness, detect deviation in the condition at an early stage, cost- effective, flexible for adding new CM techniques, provide accurate decisions and scalable. The developed framework could be used as a base to design a maintenance system for Industry 4.0. This study contributes to our understanding of the maintenance importance in today’s industry and how to develop a maintenance approach for Industry 4.0.

  • 27.
    Alhameedi, Ali
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Hybrid testing procedure development: An experimental study a hybrid simulation of a steel truss element2019Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Hybrid simulation is a numerical and experimental structural testing technique in which the critical structural members are tested experimentally, while the rest of the structure is modeled numerically. During hybrid testing, the numerical model is updated continuously based on the output of the experimental test. In this study, a quasi-static hybrid simulation was conducted on a steel truss structure. A single truss member was considered as the physical substructure, while the remaining members were modeled using Abaqus finite element software. The communication between the physical and numerical models was established using OpenFresco as a middleware. Using this setup, the structure was loaded until the physical substructure failed due to buckling. Finally, the results of the hybrid simulation were verified numerically and experimentally.

  • 28.
    Ali Qahtan, Nawar
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Donna, Sojeva
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    En alternativ mötesplats i modern arbetsmiljö2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Studien behandlar utformning av en tillbyggnad som länkas samman med en befintlig byggnad och en planerad byggnad. Det på uppdrag av Videum AB som planerar att bygga ett nytt kontorshotell på Videum Science Park och vill ha en interstruktur som innehåller restaurang, reception och konferensrum. Denna tillbyggnad ska bli mötesplatsen för Videums personal, hyresgäster och för allmänheten.

    Resultatet visar ritningar, illustrationer och förklaringar över interstrukturen.

  • 29.
    Ali, Sharafat
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET). Corning Inc, USA.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggd miljö och energiteknik (BET).
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Synthesis and characterization of the mechanical and optical properties of Ca-Si-O-N thin films deposited by RF magnetron sputtering2017Inngår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 315, s. 88-94Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ca-Si-O-N thin films were deposited on commercial soda-lime silicate float glass, silica wafers and sapphire substrates by RF magnetron co-sputtering from Ca and Si targets in an Ar/N-2/O-2 gas mixture. Chemical composition, surface morphology, hardness, reduced elastic modulus and optical properties of the films were investigated using X-ray photoelectron spectroscopy, scanning electron microscopy, nanoindentation, and spectroscopic ellipsometry. It was found that the composition of the films can be controlled by the Ca target power, predominantly, and by the reactive gas flow. Thin films in the Ca-Si-O-N system are composed of N and Ca contents up to 31 eq. % and 60 eq. %, respectively. The films thickness ranges from 600 to 3000 nm and increases with increasing Ca target power. The films surface roughness varied between 2 and 12 nm, and approximately decreases with increasing power of Ca target. The hardness (4-12 GPa) and reduced elastic modulus (65-145 GPa) of the films increase and decrease with the N and Ca contents respectively. The refractive index (1.56-1.82) is primarily dictated by the N content. The properties are compared with findings for bulk glasses in the Ca-Si-(Al)-O-N systems, and it is concluded that Ca-Si-O-N thin films have higher values of hardness, elastic modulus and refractive index than bulk glasses of similar composition. (C) 2017 Elsevier B.V. All rights reserved.

  • 30.
    Alijagic, Denis
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Att uppnå god energiprestanda: En jämförelse av teoretiska energiberäkningar och verklig energianvänding i småhus2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    En studie som utfördes på uppdrag av Norrköpings kommun med syfte att undersöka varför energideklarationer visar en annan specifik energianvändning gentemot energiberäkningar. Ett stickprov togs där tio småhus energiberäkningar och energideklarationer analyserades. Dessutom genomfördes intervjuer med tre medelstora kommuner (Norrköpings-, Linköpings- och Jönköpings kommun) samt Boverket för att lokalisera möjliga fel och förbättringar gällande Boverkets Bygg Regler, BBR. Boverkets föreskrifter och allmänna råd om fastställande av byggnadens energianvändning vid normalt brukande och ett normalår, BEN, togs även i beaktande att lokalisera felkällor i upprättade energiberäkningar för hus 1-10.

  • 31.
    Al-Najjar, Nasik
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design. Byggteknik.
    FRAMTIDA VATTENFÖRSÖRJNING FÖR VÄXJÖ KOMMUN: BEDÖMNING AV OLIKA ALTERNATIV2008Inngår i: Vatten, ISSN 0042-2886, Vol. 63, nr 4, s. 299-311Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [sv]

    Water supply in Växjö municipality has since 1887 been based on surface water from Helga lake. A water treatment plant was built in 1957 and was extensively reconstructed in 1969 but there are still problems to accomplish with drinking water quality, mainly related to temperature, smell and taste, managanese and aluminum rest. Present water consumption periodically approached the water treatment plant maximum capacity. A performed risk analysis showed that catastrophic consequences for the water supply could occur due to an accident in a nearby traffic route or discharges from an industrial area.

    In 1997 Växjö municipality decided to perform a comprehensive investigation of different alternatives for future water supply. Seven alternatives were evaluated including remedial measures at the present water treatment plant. The chosen alternative was based on supply and conveying ground water from Berga esker at Ljungby municipality. Re-infiltration of ground water will be used to guarantee required water quality and quantity and will be implemented in autumn 2008 with a planned supply of 200 l per second delivered to about 70.000 persons in the municipalities of Växjö and Alvesta. The article describes the different alternatives, motives for the chosen alternative and the evaluation procedure.

  • 32.
    Al-Najjar, Nasik
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design. Byggteknik.
    Hultman, Bengt
    Cost-Effective Water Supply and Sanitation2008Inngår i: 2nd-Environmental Conference-Water (KECW007), Dohuk Kurdistan Region in Iraq, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Water supply and sanitation have about the same goals all over the world. The needs for safe water supply and sanitation are obvious although not generally implemented. This depends often on the economical situation and bad management. Additional factors are effects of war actions and natural disasters as flooding of rivers and tsunamis. The strategies are, however, similar independent of the actual conditions. In this paper the strategies as developed in Sweden are described related to practical implementation of technology and management strategies. The experiences have shown on both mistakes and successful handling. Today, Sweden is involved in both adjusting policies according to European Union rules (as EU Water Framework Directive) and also in sharing experiences to facilitate international implementation of cost-effective methods.

  • 33.
    Al-Najjar, Nasik
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design. Byggteknik.
    Hultman, Bengt
    VA - SITUATIONEN I IRAK: PROBLEM OCH MÖJLIGHETER TILL MOTÅTGÄRDER2004Inngår i: VATTEN: Tidskrift för vattenvård, ISSN 0042-2886, Vol. 60, nr 4, s. 269-274Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [sv]

    A summary is given on the water and wastewater situation in Iraq before the Gulf war 1991, the situation after the Gulf war and the recent effects of the conflict 2003. The access of safe water was halved in certain counties after March 2003 and half of the sewage works was out of function with a discharge of untreated wastewater to rivers and channels. The supply of electricity was less than 4 hours per day in January 2004 and caused discharges of untreated sewage on streets etc. Leakage from the water net was estimated to 60%. The wastewater system in 3 out of 5 schools was estimated to be out of function and epidemics have especially affected children and caused an increased mortality. Special issues as illegal openings of water pipes and security have worsened the situation. Swedish knowledge in water and wastewater handling may have an important role in rebuilding water and wastewater handling in Iraq and different possibilities are given.

  • 34.
    Al-Najjar, Nasik
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Hultman, Bengt
    KTH, Stockholm.
    Water management and technology in Swedish municipalities.: Assessment of possibilities of exchange and transfer of experiences.2009Inngår i: An International Perspective on Environmental and Water Resources Conference, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The water and wastewater infrastructure began to be developed in Sweden more than one hundred years ago. Much attention was given, in the beginning, to fire prevention and hygienic problems with water borne diseases. Somewhat later storm sewers (combined system) were constructed to remove storm water and wastewater and then successively more efficient wastewater treatment plants were developed. Today water and wastewater handling is seen as a multidisciplinary subject where also attention is given to possible effects of climate changes and possibilities for resources recovery.

    Implementation of advanced water and wastewater systems involves not only different technologies but also effective administration and legislation. The implementation may be on national (also involving EU directives), regional and local scale. As a case study, the local implementation will be illustrated for the municipality Växjö in South Sweden with about 80,000 inhabitants.

  • 35.
    Alriksson, Tobias
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Visualisering av byggprojekt i Revit2014Independent thesis Basic level (degree of Bachelor), 180 hpOppgave
    Abstract [sv]

    Rapporten avhandlar visualiseringen i marknadsföringsstadiet av ett byggnadsprojekt med tillämpning på Trivselhus bostäder. För att få en grund till vad som ska ändras gällande företagets nuvarande visualisering har intervjuer genomförts med samtliga berörda parter. Dessa är säljare, kunder och husdesigners. Efter detta har två förslag till förändringar av nuvarande visualiseringar arbetats fram i Revit med intervjuerna som underlag.

  • 36.
    Andersen, Mattias
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Claeson, Martin
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Utvärdering av ett nyutvecklat samverkansbjälklag och dess utvecklingspotential2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I dagens byggnader ställs allt högre krav på stora rum och öppna ytor vilket ger efterfrågan på ökad spännvidd hos bjälklagen. Detta är svårt att klara av med traditionella träbjälklag. För att ändå få ett lätt bjälklag undersöks möjligheten att kunna fördela ut bjälklagets belastning i två riktningar. Bjälklaget ska alltså vara fyrsidigt upplagt. För att lösa detta har en idé uppkommit som går ut på ett samverkansbjälklag mellan trä och plåt. Detta bjälklag ska i bärriktning 1 bära genom fackverkan medan det i bärriktning 2 ska bära genom balkverkan. För att ett fyrsidigt upplagt bjälklag ska fungera krävs att sambandet mellan kraft och deformation är likvärdigt i båda riktningarna.

    Examensarbetets uppgift har varit att tillverka provkroppar för att undersöka sambandet mellan kraft och deformation i både bärriktning 1 och bärriktning 2. Provning utförs för att se om bjälklaget har förutsättningar att kunna användas i praktiken.

    Efter provning av bjälklagsprovkropparna konstaterades att det finns möjligheter att gå vidare med produkten och fortsätta utvecklingsarbetet. För de provkroppar som provades i bärriktning 1 och 2 var sambandet mellan kraft och deformation nära identisk upp till 7,5 kN då mittnedböjningen var ca 10 mm.

  • 37.
    Andersson, Alexander
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Bergman, Carl
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Underlag för fördelaktig upphängning av kylvattenledningar i en äldre byggnad2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Arbetet redovisar möjligheterna att hänga upp tyngre vattenledningar i en äldre industrilokal där en äldre byggnadsstandard användes vid uppförandet.

    Ett flertal alternativ har tagits fram och där de mest lämpade har arbetats vidare genom att jämföra fördelar och nackdelar.

  • 38.
    Andersson, Anneli
    et al.
    École Polytechnique of Montréal, Canada.
    Laurent, Patrick
    École Polytechnique of Montréal, Canada.
    Kihn, Anne
    Université Libre de Bruxelles, Belgium.
    Prévost, Michèle
    École Polytechnique of Montréal, Canada.
    Servais, Pierre
    Université Libre de Bruxelles, Belgium.
    Impact of temperature on nitrification in biological activated carbon (BAC) filters used for drinking water treatment2001Inngår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 35, nr 12, s. 2923-2934Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The impact of temperature on nitrification in biological granular activated carbon (GAC) filters was evaluated in order to improve the understanding of the nitrification process in drinking water treatment. The study was conducted in a northern climate where very cold water temperatures (below 2°C) prevail for extended periods and rapid shifts of temperature are frequent in the spring and fall. Ammonia removals were monitored and the fixed nitrifying biomass was measured using a method of potential nitrifying activity. The impact of temperature was evaluated on two different filter media: an opened superstructure wood-based activated carbon and a closed superstructure activated carbon-based on bituminous coal. The study was conducted at two levels: pilot scale (first-stage filters) and full-scale (second-stage filters) and the results indicate a strong temperature impact on nitrification activity. Ammonia removal capacities ranged from 40 to 90% in pilot filters, at temperatures above 10°C, while more than 90% ammonia was removed in the full-scale filters for the same temperature range. At moderate temperatures (4–10°C), the first stage pilot filters removed 10–40% of incoming ammonia for both media (opened and closed superstructure). In the full-scale filters, a difference between the two media in nitrification performances was observed at moderate temperatures: the ammonia removal rate in the opened superstructure support (more than 90%) was higher than in the closed superstructure support (45%). At low temperatures (below 4°C) both media performed poorly. Ammonia removal capacities were below 30% in both pilot- and full-scale filters.

  • 39.
    Andersson, Bernt-Ove
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Malmstedt, Anthon
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Innovativa boendeformer för unga vuxna: En möjlig väg in på den svenska bostadsmarknaden2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I detta arbete beskrivs intresset för och kännedomen om tre innovativa boendeformer som riktar sig till unga vuxna mellan 18 och 35 år på den svenska bostadsmarknaden. Det belyser det befintliga beståndet av bostäder och unga vuxnas största hinder för att erhålla en bostad. Arbetet tar sin utgångspunkt i den rådande bostadsbristen i Sverige, där flertalet grupper av olika skäl upplever hinder att ta sig in på bostadsmarknaden. Detta bidrar till att offentliga aktörer och olika bostadsutvecklare behöver hitta nya sätt för att underlätta för utsatta grupper att erhålla en bostad. Studien baseras på litteraturstudier av bland annat tidigare forskning, enkätundersökningar med unga vuxna och intervjuer med representanter från olika delar av branschen. Resultaten visar ett intresse för, men låg kännedom om, de tre boendeformerna: hyrköp, ungdomsettor och kooperativa hyresrätter. Dessa är alla anpassade för att avhjälpa problematiken för vissa inom målgruppen, särskilt gruppen unga vuxna, att ta sig in på bostadsmarknaden.

  • 40.
    Andersson, Carl
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Pettersson, John
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Behovet av ökad kontroll i stålbyggnadskonstruktioner2019Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I arbetet undersöks behovet av ökad kontroll i stålbyggnadskonstruktioner med avseende på utförandefel. Riksdagen beslutade 1 juni 1994 att förändra Plan- och bygglagen (PBL) där förändringen trädde i kraft 1995 och bland annat innebar att hela ansvaret för en byggnads uppförande och kontroll lades på byggherren. Efter vintrarna 2009/10 och 2010/11 där flera tak rasade av snötyngden uppdagades en rad dimensionerings- och utförandefel. Under examensarbetet undersöktes vad som händer med säkerheten i byggnadskonstruktioner i stål som genomgår förändringar under dess livslängd och en jämförelse mot gällande regelverk genomfördes.

    En fältstudie och flera intervjuer genomfördes där fokus låg på utförandefel och hur förändringar av regelverk lett fram till dagens egenkontrollsystem som påverkat antalet utförandefel. Arbetets resultat visar att det kan finnas ett behov av att se över dagens kontrollsystem och att antalet allvarliga utförandefel i fallstudieobjektet ökat efter 1995.

  • 41. Andersson Chan, Anneli
    Biofiltration of Odorous Gas Emissions2006Doktoravhandling, med artikler (Annet vitenskapelig)
  • 42.
    Andersson Chan, Anneli
    City of Växjö, Sweden.
    Experience with Anammox Sludge Liquor Treatment and up-coming Challenges with Thermal Hydrolysis Effluents at The Sundet Wastewater Treatment Plant, Vaxjo Sweden2015Inngår i: Water and Energy, Washington June 8-10 2015, 2015Konferansepaper (Fagfellevurdert)
  • 43.
    Andersson Chan, Anneli
    Växjö kommun, Sweden.
    Increased nitrogen removal in existing volumes at the Sundet wastewater treatment plant, Växjö2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The HELCOM Baltic Sea Action Plan is an ambitious program to obtain good ecological status of the Baltic marine environment by 2021. Sweden has a preliminary commitment to reduce nitrogen by 21 000 ton, partly from the wastewater sector (3 000 ton nitrogen), and due to this many wastewater treatment plants need to improve their nitrogen removal. On top of that, the incoming load of nitrogen is increasing due to rising protein consumption. Co-digestion of external substrates (often rich in nitrogen) with wastewater sludge for increased biogas production further contributes to higher nitrogen loads. Increased nitrogen removal capacity often means more bioreactor volumes, which can be very expensive and sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes.

    The Sundet WWTP in Växjö received a new environmental permit in 2010 for 95 000 pe. Emission criteria for treated water are 10 mg BOD7/l, 0.2 mg P/l, and 60% nitrification. During a five year evaluation period (2012- 2016) assessments to ensure 15 mg N/l in the effluent should be conducted. To increase the nitrogen removal capacity within existing volumes, two processes using MBBR technology with plastic carriers were chosen:

    • Increased nitrification capacity in the existing activated sludge system through the Hybas™ combination process of MBBR and activated sludge (Integrated Fixed-Film Activated Sludge, IFAS).

    • Separate biological treatment of sludge liquor with the AnitaMox™ process, using autotrophic Nremoval through anaerobic ammonium oxidation (anammox) in a one-stage process with carriers.

    One of the six treatment trains was rebuilt to fit the integrated fixed-film activated sludge process for improved nitrification. The anoxic zone in this train was doubled for improved denitrification capacity. Data collected onsite from over a year (from October 2011 to present) are analyzed and compared with the performance of a conventional activated sludge train operated in parallel.

    The Hybas trained nitrified more consistently than the reference train, with effluent concentrations <1 mg NH4- N/l for most of the time. To keep the nitrification capacity in the reference train during the winter, a higher MLSS concentration was required, as well as larger aerated volumes. This lead to inadequate denitrification, while the capacity was substantially higher in the Hybas train, with emission concentrations well under the objective of 15 mg N/l. No additional carbon was added to the system. Practical experiences concerning operational requirements and challenges of the Hybas process (air flow and hydraulic loading, carrier management, and nutrient limitations) are discussed in the paper.

    The existing sludge liquor treatment (SBR, sequence batch reactor) was retrofitted in 2011 to an AnitaMox process. Thanks to a seeding start-up strategy, the process reached full capacity with more than 90% ammonia removal within two months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period. Full-scale experiences from more than a year has proven AnitaMox to be an energy- and cost efficient nitrogen removal process compared to the previous SBR process, and at the same time robust and relatively simple to operate. However, an increased process control and more on-line instruments require resources and qualified personnel.

    These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications will improve the future operation at the Sundet WWTP.

  • 44.
    Andersson Chan, Anneli
    Växjö kommun, Sweden.
    Sustainable Biogas Production in the Greenest City in Europe2015Inngår i: IBIO 2015 - BIT's 8th World Congress of Industrial Biotechnology, Nanjing China April 25-28, 2015Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 45. Andersson Chan, Anneli
    et al.
    Johansson, N
    Christensson, Magnus
    Växjö - a holistic approach to increased biogas production2013Inngår i: Sludge Management and Anaerobic Digestion in a Broad Holistic System Perspective, 6-8 May 2013, Västerås, Sweden., 2013Konferansepaper (Fagfellevurdert)
  • 46.
    Andersson Chan, Anneli
    et al.
    Växjö kommun, Tekniska förvaltningen, Sweden.
    Johansson, Niklas
    Växjö kommun, Tekniska förvaltningen, Sweden.
    Christensson, Magnus
    AnoxKaldnes, Lund, Sweden.
    Increased nitrogen removal in existing volumes at Sundet wastewater treatment plant, Växjö2014Inngår i: Water practice and technology, E-ISSN 1751-231X, Vol. 9, nr 2, s. 215-224Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many wastewater treatment plants need to improve their nitrogen removal due to stricter requirements and increasing loads. This often means larger bioreactor volumes, which can be very expensive and is sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes. Two full-scale demonstration projects using moving bed biofilm reactor (MBBR) technology has proven to be an efficient way to treat nitrogen in existing volumes at Sundet wastewater treatment plant in Växjö. Increased nitrification and denitrification capacity in parts of the main stream were demonstrated through the Hybas™ process, a combination of MBBR and activated sludge using the integrated fixed-film activated sludge technology. The ANITA™ Mox process, using autotrophic N-removal through anaerobic ammonium oxidation (anammox), provided high nitrogen removal for the sludge liquor. Data collected on-site for over a year are analyzed and compared with the performance of conventional treatment systems. These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications have been identified that will improve future operation at Sundet WWTP.

  • 47.
    Andersson, Jenny
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Malin, Enbom
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Hur ökas implementering av visuella arbetssätt inom Skanska?2015Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Visuella arbetssätt har visat sig vara effektivt inom byggbranschen. Studien omfattar de visuella arbetssätt som Skanska använder sig av; visuell styrning och visuell projektering. Syftet med studien är att öka antalet projekt som väljer att implementera arbetssätten. Därav har underliggande problem identifierats varför inte projekt väljer att implementera arbetssätten i den utsträckning som Skanska önskar.

    Det har visat sig under studiens gång att visuell projektering har implementerats i större utsträckning än visuell styrning, detta för att visuell projektering har ett mer utvecklat underlag. En jämförelse av verktygens implementering har gjorts.

  • 48.
    Andersson, Josefine
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Svensson, Simon
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Mätning av fuktkvot i sammansatta KL-träelement2018Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Fuktskador är ett problem som kan uppstå vid byggnation i trä om konstruktionen exponeras för nederbörd under byggtiden. Mätning av fuktkvoter i trä kan utföras med flera olika instrument och metoder. Syftet med arbetet är att studera fuktkvotsförändringar i korslimmade träelement som utsätts för långvarig nederbörd i laborationsmiljö. För att utveckla detta område har Linnéuniversitetet tillsammans med Saab utvecklat ett eget mätinstrument. Instrumentet mäter resistans i trä som jämförs med mätvärden från ett annat instrument vid namn Gigamodule. Det egenutvecklade sensorkortet är fortfarande under utveckling. Förutom i arbetets försöksuppställning testas instrumentet även i en byggnad i Växjö.

    För kontroll av mätresultat har fler metoder och instrument använts. Två modeller har använts som representerar detalj vid anslutning av väggelement-och mellanbjälklag. Båda modellerna har under lika lång tid varit nedsänkta i vattenbad. Försöksuppställningen har utförts mellan 19:e april och 18:e maj 2018. Mätningar och beräkningar har resulterat i jämförbara resultat. Skillnader i resultat utifrån träets fiberriktning har visats från flera instrument. KL-träelementen har uppvisat en god förmåga att trots höga fuktkvotsvärden torka ut och återgå mot normala värden under mätperioden. 

  • 49.
    Andersson, Magnus
    et al.
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Cederholm, Anders
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Alternativa byggsystem för att minska transmissionsförlusterna på miljonprogrammets byggnader2009Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The purpose with this project is to explore and verify three renovating systems for Miljonprogrammet (common expression for

    buildings constructed during the years 1965-1975 when over a million houses where built in Sweden) to take measure to the

    largely transmission losses of these buildings. Many of the buildings from this period have similar constructions and therefore

    the same techniques can be used to renovate several of them. This project only considers the climate scale, although there

    are many more factors to concern for to efficient the buildings of Miljonprogrammet.

    This thesis presents examples of renovations carried out using two of the three renovation systems.

    The essay presents a reference house of choice on which we apply the three systems and calculate the new U-values,

    consumption of energy and the investment costs. The new U-values the building is given is matched to the values of

    recommendation for passive houses. Our reference house is a two story apartment building, located in the village of

    Lammhult, with brick facades at the ends and plaster at the long sides. One of the long sides contains balconies. The three

    systems are additional insulation, prefabricated additional insulation and replacement of the facade. We consider which

    renovation systems are best in different conditions, also considering the treatment of the tenants.

    The result of the study shows that with additional insulation and prefabricated additional insulation the buildings transmission

    losses will be major lowered. The investment cost and payoff time for the prefabricated version is much lower. If the standard

    of passive house is wanted the replacement of facade technique should be used. This method requires that the tenants move

    out during the renovation work. The investment cost for this method is significantly higher but the payoff time is equal with the

    additional insulation methods payoff time

     

     

    .

  • 50.
    Andersson, Matilda
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Ekholm, Matilda
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Källström, Sofia
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för byggteknik (BY).
    Utveckling av en grönyta i ett miljonprogramsområde2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Detta examensarbete ger ett studerat utformningsförslag på ett outnyttjat grönområde imiljonprogramsområdet Norrliden i Kalmar.Studien har resulterat i ett förslag till förbättrad utformning, en visuell skiss utifrånrelevant teori, intervjuer med sakkunniga och enkätsvar från de som bor i området. Fokushar legat på att öka gemenskap mellan människor i olika åldrar, kön och bakgrund.

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