| 1. |
- Desivyana, Nindya, 1997, et al.
(författare)
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Challenges in the adoption of sustainable criteria in the Swedish property development industry
- 2023
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Ingår i: Procedia Computer Science. - : Elsevier BV. - 1877-0509. ; 219, s. 1752-1759
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Konferensbidrag (refereegranskat)abstract
- The construction industry is facing an increased focus on sustainability and climate neutrality, causing property developers to implement new requirements into the procurement documents, which are also driven by the national agenda. This study explores the current state of sustainability practice among Swedish property developers and identifies the main obstacles to expand further the implementation of the sustainability criteria. How the property developers define and implement sustainability requirements has been assessed through qualitative semi-structured interviews, focusing on sustainability certification systems, Life Cycle Assessment (LCA), and social sustainability. The results show usage of sustainability certification systems for marketing purposes and high awareness and practice of LCA, even though the accuracy of LCA was questioned. This study also identified guideline gaps for circular economy and social sustainability measurements, which could relate to low initiatives from the certification systems.
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| 2. |
- Femenias, Paula, 1966, et al.
(författare)
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Från omfattande till varsam renovering
- 2019
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Ingår i: Hållbar renovering ur ett helhetsperspektiv: En antologi från forskningsmiljön SIRen. - 9789188722652 ; , s. 47-54
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
- Rempling, Rasmus, 1976, et al.
(författare)
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Utmattning
- 2021
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Ingår i: Betonghandbok material - Hårdnad betong, fysikaliska egenskaper och beständighet. - 9789179170882 ; , s. 485-510
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Concrete Support Structures for Offshore Wind Turbines: Current Status, Challenges, and Future Trends
- 2021
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 14:7
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Forskningsöversikt (refereegranskat)abstract
- Today’s offshore wind turbine support structures market is largely dominated by steel structures, since steel monopiles account for the vast majority of installations in the last decade and new types of multi-leg steel structures have been developed in recent years. However, as wind turbines become bigger, and potential sites for offshore wind farms are located in ever deeper waters and ever further from the shore, the conditions for the design, transport, and installation of support structures are changing. In light of these facts, this paper identifies and categorizes the challenges and future trends related to the use of concrete for support structures of future offshore wind projects. To do so, recent advances and technologies still under development for both bottom-fixed and floating concrete support structures have been reviewed. It was found that these new developments meet the challenges associated with the use of concrete support structures, as they will allow the production costs to be lowered and transport and installation to be facilitated. New technologies for concrete support structures used at medium and great water depths are also being developed and are expected to become more common in future offshore wind installations. Therefore, the new developments identified in this paper show the likelihood of an increase in the use of concrete support structures in future offshore wind farms. These developments also indicate that the complexity of future support structures will increase due to the development of hybrid structures combining steel and concrete. These evolutions call for new knowledge and technical know-how in order to allow reliable structures to be built and risk-free offshore installation to be executed.
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| 6. |
- Billger, Monica, 1961
(författare)
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Färg, ljus och rumslig dynamik
- 2014
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Ingår i: Färg & Ljus för människan i rummet. - 9789173336536 ; , s. 201-219
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Hagbert, Pernilla, et al.
(författare)
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Paradoxes and possibilities for a 'green' housing sector : A swedish case
- 2013
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 5:5, s. 2018-2035
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Tidskriftsartikel (refereegranskat)abstract
- As global and local visions for sustainable living environments are increasingly supported by policies and concrete practices in construction, the building and housing sector is seeking to mitigate its environmental impact as well as assume a greater social responsibility. The overarching policy objectives set to concretize what a sustainable housing development entails, however, tend to rely on equivocal terminology, allowing a varied interpretation by key industry practitioners. Though in line with an ecological modernization paradigm in policy, the promotion of a market-driven environmentalism in housing faces multiple challenges as varying interests and perspectives collide. Supported by empirical findings of a semi-structured interview study conducted with housing developers in a new =green' urban district in Göteborg, Sweden, theoretical frameworks surrounding the paradoxical path towards a sustainable housing development are presented. Inconsistencies between outspoken ambitions; social dimensions; and the framing of efficiency in new housing are discussed. Possibilities for the housing sector are given in the recognition of new forms of development, where a systemic perspective is required in the alignment between how industry, policy and the market perceives housing development and what is actually sustainable.
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| 8. |
- Hellwig, Runa T., et al.
(författare)
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The potential of the adaptive thermal comfort concept in long-term actively conditioned buildings for improved energy performance and user wellbeing
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:3
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Konferensbidrag (refereegranskat)abstract
- Technological progress in conditioning practice combined with prevailing thermal comfort criteria, created stable, tightly controlled indoor temperature bands. Research shows indoor temperatures to be increasing in the heating period, leading to higher building energy use than planned. Field studies provide proof that occupants not in control of their indoor climate are more dissatisfied and report problems in wellbeing. Widening temperature bands could be an effective measure leading to energy conservation, increasing satisfaction and, as shown recently, helping to mitigate health problems related to our way of life. The adaptive approach to thermal comfort postulates that people's thermal comfort perception adapts to the indoor and outdoor climatic conditions they normally experience. However, according to standards, the adaptive model is applicable only to passively conditioned (free-running) buildings, even though the adaptive principles may well apply also to actively conditioned buildings. Our review found studies demonstrating positive health effects and energy conservation potential in permanently or seasonally conditioned buildings. On this basis, the potential of the adaptive approach and translations into concrete design or operation solutions for actively conditioned buildings are discussed in this paper. We conclude that the adaptive concept offers a potential for indoor climate control in actively conditioned buildings in the temperate and cold climates.
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| 9. |
- Johansson, Pär, 1986, et al.
(författare)
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Aerogelbaserad puts för energieffektivisering av äldre och kulturhistoriskt värdefulla byggnader (webinar)
- 2021
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- I denna webinar i samarbete med Energimyndighetens program Spara och Bevara introduceras aerogelbaserad puts och vi beskriver hur materialet kan bidra till renovering och energieffektivisering. I webinariet presenteras också helt färska forskningsresultat. Många äldre byggnader är svåra att renovera för att uppnå en god energibesparing. Detta gäller speciellt för kulturhistoriska byggnader där det finns begränsningar i möjliga praktiska och tekniska lösningar. Byggnadernas karaktärsdrag, begränsningar i tillåten väggtjocklek i bygglov och risker for fuktrelaterade skador är bara några exempel. I ett forskningsprojekt på Chalmers studeras en ny typ av isolerande puts. Denna puts är baserad på aerogelpartiklar som möjliggör fler tekniska lösningar vid renovering och energieffektivisering än konventionell puts. Aerogelbaserad puts är kalk- eller cementbaserad och innehåller aerogel som är ett superisolerande material. Dess värmekonduktivitet är under 0,020 W/m·K, ungefär hälften av mineralullsisolering. Aerogelpartiklarna ger den aerogelbaserade putsen isolerande egenskaper jämförbara med konventionella isoleringsmaterial. Förutom bättre isolerande egenskaper jämfört med vanlig puts är den aerogelbaserade putsen fuktdiffusionsöppen och har en hög fuktkapacitet. Detta är fördelaktiga egenskaper för att uppnå en fuktsäker konstruktion. Aerogelbaserad puts kan vara en del av lösningen på utmaningarna för att renovera kulturhistoriska byggnader, utan att förvanska utseendet, samtidigt som tjockleken på isoleringen kan minska. Nu utvärderas materialet ur värme- och fuktsynpunkt för användning i svenska byggnader och klimatförhållanden.
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| 10. |
- Johansson, Pär, 1986, et al.
(författare)
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Interior insulation using super insulation materials: saving energy and space
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:5
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Konferensbidrag (refereegranskat)abstract
- Interior insulation can be used in buildings where the exterior characteristics may not be altered due to cultural heritage protection. This is common for many buildings in Sweden from the period before 1941. Energy efficiency, thermal comfort and building performance are all affected by an interior insulation. Super insulation materials present novel opportunities to save both energy and space. The aim of this study is to investigate the benefits and drawbacks of using super insulation materials as interior insulation. A field study building was investigated for feasibility, which, together with interviews with professionals in the field of architecture, cultural heritage and building consultants, give a general overview. In conclusion, there are both benefits and drawbacks with interior insulation. Super insulation provides increased flexibility in terms of interior detailing and possibility to preserve characteristic elements. On building level interior super insulation could reduce the energy use by up to 20%. This gives energy savings of 0.5 TWh on national level and a reduction of 0.7% of the total CO2 emissions for heating the Swedish building stock. A drawback is that there are few examples and little experience from building with super insulation materials among both architects and other decision makers.
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| 11. |
- Karim, Ali Naman, 1992, et al.
(författare)
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Aerogelbaserad puts- Superisolering för framtiden
- 2020
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Ingår i: Husbyggaren. ; :6, s. 8-11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- I ett forskningsprojekt på Chalmers studeras en aerogelbaserad puts med mycket bra isolerande egenskaper. Förhoppningen är att användningen av den så kallade superisolerande putsen ska bidra till att minska byggsektorns energianvändning, både för existerande och nya byggnader. Superisolerande puts kan, förutom att spara energi, dessutom resultera i funktionella väggar med mindre tjocklek. Detta bidrar i sin tur till att öka mängden uthyrningsbar golvyta inomhus, yta som annars skulle tagits upp av väggens isolering. I denna artikel vill vi informera om vad vi planerar att göra i projektet och berätta om den superisolerande putsens egenskaper.
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| 12. |
- Karim, Ali Naman, 1992, et al.
(författare)
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Super insulation plasters in renovation of buildings in Sweden: energy efficiency and possibilities with new building materials
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:4
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Konferensbidrag (refereegranskat)abstract
- Super insulation plasters are new and high energy efficient plasters mixed with aerogel particles. Aerogel is a porous and low-density material with very low thermal conductivity compared to the traditional insulation materials. Today, approximately 27% of Sweden’s multi-family houses have a plaster façade. Plaster is commonly used in many other European countries as well. In this paper, numerical simulations are utilized to estimate the total magnitude of energy and CO2 emissions that can be saved annually in Sweden by using super insulation plasters. In additional, possibilities and challenges in conjunction with the introduction of new techniques and materials in the building sector have been addressed, through interviews and literature review. The annual energy use and CO2 emissions can be reduced by 74±48 GWh and 1000 ±600 ton respectively if 10% of Sweden’s multi-family houses are externally insulated by super insulation plaster. Based on the interviews it is evident that distinct information and documentation about a new building material, concerning the material properties and long-termperformance, needs to be provided by the producer before usage of the material on industrial scale. Another important issue is the cost of a new technique and that it has to be economically motivated. Implementation of the super insulation plaster in Swedish buildings can contribute to achieving the sustainable development goals numbers 7, 8 and 9 by 2030, by increasing the energy efficiency of buildings and productivity on construction sites.
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| 13. |
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| 14. |
- Stephen, Jake, et al.
(författare)
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Internal thermal environment and futureproofing of a newly built, naturally ventilated UK school
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:3
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Konferensbidrag (refereegranskat)abstract
- Research indicates that school children have lower comfort levels than adults and this exacerbates the challenge of tackling the risks of summer overheating in schools without resorting to air conditioning. UN SDG 13 calls for climate action to strengthen the resilience of our cities and reduce the impact of climate change. In this work, a modern, naturally ventilated school in Southampton, UK was used to evaluate single, "hard", passive retrofit measures and "soft", building management solutions that could increase the wellbeing of students and reduce current and future demand for cooling. The school was selected as it represents the current standardised design guidance for schools released in 2012 by the Department of Education (DfE). The research presents air temperature observations collected during the summer of 2015. Dynamic thermal modelling was undertaken to evaluate passive retrofit and "soft" solutions to reduce the overheating risk. The model was validated with temperature data collected from the school classrooms. The results indicate that (a) such school buildings have high likelihood of overheating, based on children's comfort temperatures and (b) passive retrofits focused on shading and ventilation could help to reduce the classroom temperature when required. It is recommended that "soft" adaptive solutions will prove effective to reduce future air conditioning demand, but this will require a radical change in established practices. Achieving the UN Sustainable Development Goals by 2030 will require to rethink and redesign urban living and city infrastructures.
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| 15. |
- Teli, Despoina, 1980, et al.
(författare)
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Teaching the concept of adaptive thermal comfort in building design education
- 2020
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Ingår i: 16th Conference of the International Society of Indoor Air Quality and Climate: Creative and Smart Solutions for Better Built Environments, Indoor Air 2020.
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Konferensbidrag (refereegranskat)abstract
- Traditional building design education in the disciplines of building services, civil engineering, mechanical engineering, etc. focusses on quantifiable factors, i.e. factors which can be subject of calculation, simulation and dimensioning. Since non-quantifiable factors are not part of calculation or simulation models, there is a tendency that they are not adequately considered in education and, as a result, in building planning and operation. In the case of human thermal comfort, building professionals are required to understand the mechanisms and impact of non-quantifiable factors related to human thermal comfort and health, most of which are part of the adaptive thermal comfort concept. This paper identifies the challenges in teaching the concept of adaptive thermal comfort through a collection of lived experiences of the authors. The paper then proposes appropriate intended learning outcomes and teaching methods to equip students with the background knowledge, understanding and skills required to consider human adaptation in their designs. It is widely accepted that integrated design is a precondition for a building design that functions well, offers sufficient comfort for their users and can be operated in a sustainable way. Integrated building design requires that different disciplines work closely together and understand and respect their different focus areas and languages. Herein the case of human thermal comfort requires engineers who understand the mechanisms and impact of non-quantifiable factors on human well-being indoors. Within the work of Annex 69: “Strategy and practice of adaptive thermal comfort in low energy buildings” we developed a framework and a guideline for adopting adaptive thermal comfort principles in design and operation of buildings, which may serve as a complementary tool in an integrated design process and inclusion of adaptive thermal comfort in education.
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| 16. |
- Williams Portal, Natalie, 1986, et al.
(författare)
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Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements
- 2017
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Ingår i: Composite Structures. - : Elsevier BV. - 0263-8223 .- 1879-1085. ; 177, s. 104-118
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Tidskriftsartikel (refereegranskat)abstract
- A novel sandwich element design consisting of two facings made of carbon reinforced Textile Reinforced Concrete (TRC), a low density foamed concrete (FC) core and glass fibre reinforced polymer (GFRP) connecting devices was experimentally investigated according to quasi-static and cyclic quasi-static four-point bending. Optical measurements based on Digital Image Correlation (DIC) were taken during testing to enable a detailed analysis of the bending behaviour and level of composite action. A model, verified by the experiments, was developed based on non-linear finite element analysis (NLFEA) to gain further insight on the failure mechanisms. Under both loading conditions, the bending behaviour of the TRC-FC composite elements was characterized by favourable load bearing capacity, partial composite action, superior ductility and multiple fine cracking. The connecting devices were found to be the critical elements causing the initial failure mechanism in the form of localized pull-out within an element.
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| 17. |
- Rempling, Rasmus, 1976, et al.
(författare)
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Performance requirements for Swedish transport infrastructure - A pre-study of challenges and possibilities
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, significant worldwide research has been conducted regarding the performance assessment of bridges and the concept of performance indicator has been introduced However, there are still significant discrepancies in how these indicators are obtained and used. Simultaneously, it is desirable to achieve processes and methods that are direct, i.e. that measured values are directly compared with projected values over time. This project concerns methods for verification of technical performance requirements. The feasibility study brought together interdisciplinary researchers, consultants, and entrepreneurs to gather knowledge, anchor the research agenda, and implement performance requirements. The project concludes that there is a need for a “Holistic multi-parameter verification/validation system” that relies on the knowledge gained in structural health monitoring research.
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| 18. |
- Säwén, Toivo, 1993
(författare)
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Early Stage Architectural Design Practice Perspectives on Life Cycle Building Performance Assessment
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Architectural practitioners can avoid negative social and environmental impacts of new construction by making decisions supported by impact quantification during design processes. However, most software tools developed for such quantification see little use in practice, especially in early design stages when decisions have the greatest influence. To identify ways for software developers to overcome this situation, a thorough literature meta-review of previously performed tool reviews was combined with interviews applying a practice lens. The first key finding is that a possible explanation for the low tool uptake in practice could be a missing practice perspective in previous tool development efforts. In a literature meta-review of publications on life cycle building performance tools identifying previously applied perspectives, most previous tool reviews were found to support tool development and selection, while disregarding how tools can be integrated in existing practices and design processes. As a proposed solution, a framework for defining software requirements using a practice perspective was developed. The second key finding is that a practice perspective could be applied during software development by implementing qualitative methodologies. Nine architectural practitioners in Sweden, Norway and France were interviewed using the interview to the double, a projective technique in which the interviewee is asked to describe their next workday in detail so that their tasks can be assumed by an imagined body double. The design activities described by the respondents were sequenced into user narratives which could serve as starting points for participatory software development processes within the architectural practice. The outcomes - a proposed framework for practice-centric software requirements, and a proposed methodology for collecting these requirements using a practice lens - indicate a research direction toward software development efforts which aligns with design process, architectural practice, and tool user needs. In the next stage of the research this direction will be pursued through application of the developed methodologies in participatory development case studies in early-stage architectural design practice.
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| 19. |
- Ask, Anna, et al.
(författare)
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Studenters uppmärksamhet under föreläsningar
- 2009
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Ingår i: Proceedings utvecklingskonferens 09 Lunds Universitet. - 9789197797429 ; , s. 112-120
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Konferensbidrag (refereegranskat)abstract
- Föreläsningar är vanlig undervisningsform på Lunds Tekniska Högskola (LTH). Deras stora fördel är att information överförs ekonomiskt och effektivt till många studenter samtidigt men de har även sina begränsningar. Kritiker menar att information överförs till passivt mottagande studenter och att bristande uppmärksamhet och engagemang hos studenterna begränsar mängden kunskap som faktiskt tas emot. En intervju- och litteraturstudie har genomförts för att dels inventera vilka metoder som finns för att hålla studenternas uppmärksamhet uppe och dels vilka som tillämpas av föreläsare vid LTH. Variation och olika former av aktivering framstår såväl i litteraturen som i intervjuerna som viktiga metoder. I artikeln presenteras även inspiration kring hur man kan använda variation, och andra aktiviteter för att engagera och aktivera studenterna samt hur man kan strukturera en föreläsning. De flesta av de intervjuade föreläsarna uppger att de utvecklat sina strategier genom erfarenhet medan knappt hälften nämner pedagogiska kurser.
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| 20. |
- Bournas, Iason, et al.
(författare)
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Energy renovation of an office building using a holistic design approach
- 2016
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Ingår i: Journal of Building Engineering. - : Elsevier BV. - 2352-7102. ; 7:September 2016, s. 194-206
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a holistic approach to perform energy renovations of office buildings. A real case study is used to demonstrate how different software can be used to facilitate the work of architects and engineers during different design stages. Initially, the moisture safety of the building is coupled to its energy performance to define the optimum insulation level. The new interior layout is based on an initial daylight study, rather than on architectural intuition. On a second stage, shading and natural ventilation are studied to eradicate any cooling demand, while the interdependence between heating energy and daylight is assessed for the use of light-wells. To demonstrate the trade-offs between visual control and electrical lighting, different shading systems are examined for a cellular office. Finally, two alternate HVAC systems are analyzed to investigate whether passive standards can be achieved with an all-air system and/or a hydronic system.
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| 21. |
- Crocetti, Roberto, et al.
(författare)
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Stress-laminated-timber decks: state of the art and design based on Swedish practice
- 2016
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Ingår i: European Journal of Wood and Wood Products/Holz als Roh - und Werkstoff. - : Springer Science and Business Media LLC. - 1436-736X .- 0018-3768. ; 74:3, s. 453-461
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Tidskriftsartikel (refereegranskat)abstract
- Stress-laminated-timber (SLT) bridge decks area valid alternative to conventional short- and medium-spanbridges in terms of cost and performance. SLT decks aremade from a number of planks or glulam beams positionedside by side and stressed together using high-strength steelbars. A concentrated load can therefore be distributed fromthe loaded beams onto adjacent beams due to the resistingfriction caused by the pre-stressing of all beams in thedeck. This paper describes the state of the art of SLT bridgedecks, with special emphasis on Swedish practice. Theeffect of butt joints on deck deflection and solution appliedto accommodate the loss of pre-stress are shown. Simpledesign tools for the preliminary design of road bridges areillustrated. Best practice with regard to some detailing,water protection and durability is also discussed. Finally,possible developments of SLT bridges are discussed.
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| 22. |
- Hagbert, Pernilla, 1986
(författare)
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Den gröna byggbranschens paradox
- 2013
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Ingår i: Att svära i kyrkan - tjugofyra röster om evig tillväxt på en ändlig planet. - 9789198146707 ; , s. 206-217
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 23. |
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| 24. |
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| 25. |
- Desivyana, Nindya, 1997, et al.
(författare)
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Sustainability Driven Procurement of Building Projects Incentives and Driving Factors from the Clients’ Perspective
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The construction industry is reported as one of the biggest global industries which accounted 30% global greenhouse gas emissions. The challenge of the construction industry is not merely on the reduction of emissions, but also extended towards other aspects of sustainability, consisting of the environmental, social, and economic pillars of sustainability. Sweden took action to handle the environmental issues by targeting on being climate neutral by 2045. Hence, the Swedish National Board of Housing, Building, and Planning, commonly known as Boverket, took more detailed action by stipulating climate declaration for all new buildings. The property developers play a vital role to boost sustainability in Sweden, since they have an increased influence in the hierarchy of the construction industry. In this case, the drivers of sustainable development in the construction industry are partially reliant on the clients’ requirements requested in every project, as well as their ethics and initiatives. Therefore, this study investigates the state-of-the-art sustainable practices among property developers in Sweden to identify the main challenges in applying sustainable criteria during the procurement phase. This study was carried out by qualitative research which consists of a literature review and an empirical study of semi-structured interviews. This study resulted in the identification of several common sustainable criteria, covering the three pillars of sustainability and also emphasising the fact that currently the property developers have an increased interest in environmental and economic sustainability, rather than social sustainability. The results of the study also raised the notion of long-term perspective, how it affects the business strategy on sustainability and the different perceptions that exist. The study concludes that the market demand drives the implementation of the agenda on sustainability, among property developers in Sweden, while providing substantial information that could prove useful in the future development of the national agenda and its regulations.
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| 26. |
- Hagbert, Pernilla, 1986
(författare)
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Byggbranschens gröna paradox
- 2013
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Ingår i: Archileaks redaktionella material, archileaks.se.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 27. |
- Hagbert, Pernilla, 1986, et al.
(författare)
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Reducing water consumption
- 2012
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Ingår i: 1st RESPONDER Knowledge Brokerage Event on Sustainable Housing, 28-30 March, 2012, Barcelona, Spain.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 28. |
- Johansson, Mikael, 1975, et al.
(författare)
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KAN VR FÖRBÄTTRA KUNSKAPSÅTERFÖRING FRÅN PRODUKTIONEN UNDER PROJEKTERING?
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med detta projekt har varit att studera och utvärdera hur ett VR (Virtual Reality)- gränssnitt till BIM-modellen kan användas för att bättre och mer effektivt involvera och ta tillvara på produktionspersonalens kunskap redan under projekteringsfasen. Enkelt sett har grundtanken varit att låta personal med erfarenhet från produktionen "identifiera/lösa/hantera problem virtuellt – INNAN de når byggarbetsplatsen". VR-tekniken har studerats och utvärderats på sex olika arbetsplatser/projekt där projektering och produktion har pågått parallellt. Som metod har intervjuer, enkätundersökning, samt observationer används. Resultatet från studien visar att det finns stora möjligheter med – och i viss mån också ett behov av – att låta personal från produktionen använda VR-teknik för granskning, planering, och arbetsberedning. Genom att involvera och ta tillvara på produktionspersonalens kunskap och insikter har flertalet problem eller mindre bra lösningar upptäckts och hanterats, innan dessa har nått det faktiska utförandet. I vissa fall har det rört sig om rena projekteringsmissar, medans det i andra fall har handlat om ändrad arbetsordning mellan discipliner, eller alternativa lösningar som passat framdriften bättre. När det gäller VR tekniken som sådan är det framförallt det faktum att modellen betraktas i skala 1:1 som lyfts fram och många kommentarer är kopplade till hur storlek, utrymmen, och detaljer, ges en helt annan förståelse och känsla för än när modellen granskas på vanlig skärm. Vidare visade det sig att möjligheten att vara flera användare i en och samma VR[1]modell, s.k. multi-user läge, hade väldigt positiva effekter på förståelse och kommunikation mellan deltagarna. Multi-user gör det dessutom möjligt för deltagarna att koppla upp sig från vitt skilda platser, vilket spås underlätta den här typen av möten med deltagare från både projektering och produktion. Sammantaget kan det konstateras att VR definitivt har möjlighet att förbättra kunskapsåterföring från produktionen under projektering. Studien ger många exempel på problem, utmaningar, och mindre bra lösningar som kan upptäckas – men även hur man kan hitta bättre och mer produktionsanpassade lösningar – och visar tydligt att VR[1]tekniken har ett värde och är mogen för att användas kontinuerligt i skarpa projekt. Dock finns det idag fortfarande hinder och utmaningar när det gäller att göra tekniken fullt tillgänglig för alla i ett projekt, och här spås en ny generation av fristående VR-headset att öppna upp för bättre möjligheter.
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| 29. |
- Kharazmi, Parastou, 1977-
(författare)
-
Experimental evaluation of a rubber-epoxy polymeric system used in the rehabilitation of sewer infrastructure- Dataset
- 2019
-
Annan publikationabstract
- This dataset includes data related to water sorption analyses to support research findings stated in the article:"Experimental evaluation of a rubber-epoxy polymeric system used in the rehabilitation of sewer infrastructure: a case study in Sweden" with the following abstract: One rehabilitation method used mainly for wastewater sewers in residential buildings involves applying a rubber-epoxy composite to the inner surface of the aged pipeline. In order to understand the material’s performance and stability in operation, during which it is constantly exposed to deteriorative factors, the properties of the material were studied in the laboratory under artificial water and air aging conditions. Changes in the material were monitored by means of tests such as thermal analyses, mechanical testing and water absorption assessment.
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| 30. |
- Mangold, Mikael, 1982, et al.
(författare)
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Who benefits? Effects and perceptions of residential volumetric water billing
- 2012
-
Ingår i: 2nd Nordic Conference on Consumer Research, 29 May-1 June, 2012, Göteborg.
-
Konferensbidrag (refereegranskat)abstract
- What are the effects and perceptions of increased installation of water metering and volumetric billing in residential areas in Sweden? An interview study was undertaken in a low-income suburb of Göteborg to explore residents’ experiences and opinions. Additionally, the interests of water and energy companies, social affairs committee, real estate owner and maintainer were investigated to contrast the added value of reduced water consumption. Stakeholders either benefit or are disadvantaged by the introduced system. Furthermore, the applied tariff structure fails to motivate all segments of the population to reduce water consumption, yet still inequitably burdens the most financially exposed groups.
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| 31. |
- Rempling, Rasmus, 1976, et al.
(författare)
-
Research Roadmap - Information Integration in Construction
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This Roadmap is developed for a challenging Global environment where fundamental paradigms such as data generation and analysis, are shifting at a seismic rate, while change in Construction Industries across the Globe is, in the main, confined to large-scale projects and slow. Against this background, the authors set out to also give a ‘voice’ to small-to-medium scale projects through which the construction output Worldwide is delivered. Hence, project scale was one of the key considerations throughout this Roadmap. Moreover, the authors conceptualized data integration by taking the realities of doing business’ in construction into consideration. The emergent framework facilitates the discussion of knowledge and data integration at organisational, team, operational and technical levels across key project phases. This approach recognizes that business is done through projects but change can only come about if appropriate organizational structures and processes are put in place. Last, but not least, the authors strived to ensure that data integration was not considered solely from a technical perspective. Organisational, team and individual aspects of data integration were integrated in the research framework. Through our work the individual’s willingness to collaborate emerged as a critical driver for high levels of integration, while our survey did identify “Reluctance to work across professional boundaries” as a major barrier to integration. Hence, we conclude that research on integration should pay due attention to the individual.
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| 32. |
- Aygül, Mustafa, 1970, et al.
(författare)
-
A comparative study of different fatigue failure assessments of welded bridge details
- 2013
-
Ingår i: International Journal of Fatigue. - : Elsevier BV. - 0142-1123. ; 49:0, s. 62-72
-
Tidskriftsartikel (refereegranskat)abstract
- Five different welded joints frequently used in steel bridges have been selected to investigate the accuracy and applicability of three fatigue assessment methods. The first method, also categorised as the global method, is the nominal stress method, while the more advanced methods are the hot spot and the effective notch stress methods. Solid element based finite element models for welded bridge details were created by following the modelling requirements of each fatigue assessment method. A statistical evaluation based on the results of the finite element analyses and the fatigue test data collected from the literature was performed to determine the mean and characteristic fatigue strength. In addition, the standard deviation for each data series was also determined to conclude how well each method describes the fatigue strength of each welded detail. A method with a lower standard deviation is regarded as more accurate. Moreover, the evaluated results from each method were compared with the recommended fatigue strength values in the Eurocode 3 (EN 1993-1-9:2005) and IIW codes. In the light of the test results in this study, it appears that the codes are in reasonable agreement with the test data, even though a few examples of the opposite occurred. The conclusion based on the revised results in this article indicates that the nominal stress method yields satisfactory results, despite its simplicity. When considering the effort involved in creating FE models for numerical analysis, it seems clear that the choice of the nominal method is fairly acceptable.
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| 33. |
- Blomfors, Martin, et al.
(författare)
-
Reliability analysis of corroded reinforced concrete beam with regards to anchorage failure
- 2019
-
Ingår i: Life-Cycle Analysis and Assessment in Civil Engineering. - : CRC Press/Balkema. - 9781138626331 - 9781351857574 ; , s. 337-344, s. 337-344
-
Konferensbidrag (refereegranskat)abstract
- Reinforcement corrosion is a common problem in reinforced concrete infrastructure today, and it is expected to increase in the future. To simply replace the corroded structures with new ones requires large resources, both in financial and environmental terms. Therefore it is important that existing structures are used to their full potential, also after the onset of corrosion. This paper presents a reliability study of the anchorage capacity of a reinforced concrete beam including reinforcement corrosion. The sensitivity of the different input parameters is also studied. As expected, the results show that the reliability is reduced with corrosion; the magnitude depends to a large extent on the modelling uncertainty used for the bond model for corroded reinforcement. The sensitivity analysis shows an influence of corrosion also on the sensitivities of the input parameters, which is expected based on the properties of the underlying bond model. This paper demonstrates that probabilistic evaluations give valuable insight of the reliability, which can be used to prolong the service-life of existing infrastructure and save both money and the environment.
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| 34. |
- Thunberg, Micael, 1986-, et al.
(författare)
-
Categorising on-site problems : A supply chain management perspective on construction projects
- 2017
-
Ingår i: Construction Innovation. - : Emerald Group Publishing Limited. - 1471-4175 .- 1477-0857. ; 17:1, s. 90-111
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose - This study aims to identify and categorise common on-site problems from a supply chain management (SCM) perspective and to trace the origin of these problems in the construction project process, the supply chain or in the intersection between these processes. This allows for identification of how on-site problems affect SCM in construction projects and how they can be mitigated. Design/methodology/approach - A literature review in combination with semi-structured interviews was used to identify on-site problems. This enabled triangulation and strengthened both construct validity and internal validity. Findings - On-site problems can be categorised in one of the four following categories: material flows, internal communication, external communication or complexity. The first category has its origin in the supply chain, the second in the construction project process, the third in the supply chain-construction process intersection on site and the fourth in the construction project as a whole. The findings conclude that on-site problems often originate from construction companies' lack of supply chain orientation. Research limitations/implications - It is suggested that supply chain planning (SCP) can facilitate on-site problem mitigation in construction project management. This extends the body of knowledge of SCP in construction project management and supports the development of effective on-site construction project management. Practical implications - The results show that SCP can aid construction project management in handling on-site problems earlier in the project process. Originality/value - The main value lies in extending the body of knowledge in construction project management research by applying an SCM perspective and by introducing SCP to support more effective construction project management.
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| 35. |
- Jockwer, Robert, 1984, et al.
(författare)
-
Design for adaption - making timber buildings ready for circular use and extended service life
- 2021
-
Ingår i: World Conference on Timber Engineering 2021, WCTE 2021.
-
Konferensbidrag (refereegranskat)abstract
- The use of timber and the implementation of the concept of circularity in the process of the construction of buildings potentially has a high sustainability impact, both from the perspective of material and construction technique. The three most effective ways to ensure the benefit of the circularity in the building sector in general are (1) maintain the service life of structures and buildings materials as long as possible to avoid unnecessary emissions and costs for demolition and reconstruction (2) conserve the quality of materials as long as possible to avoid unnecessary emissions and costs for the replacement and processing of new materials and (3) recycle and repurpose only the parts and materials which cannot function any more for technical and/or socio-cultural reasons. In this paper an approach is discussed towards a more sustainable built environment by making buildings adaptable to the changes of demands and requirements to building functions and thus leading to an extended use of buildings in a maximum of life cycles. This design for adaption may enhance economic, social and environmental benefits to various stakeholders and key players related to the building process, i.e. developers, building owners, users, municipality and others.
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| 36. |
- Täljsten, Björn, 1961-, et al.
(författare)
-
Assessment of prestressed concrete bridges - challenges
- 2020
-
Ingår i: IABSE Symposium, Wroclaw 2020. - Zürich : International Association For Bridge And Structural Engineering (IABSE). ; , s. 487-494
-
Konferensbidrag (refereegranskat)abstract
- Prestressed concrete bridges are important parts of our infrastructure. They are susceptible to different kinds of deterioration processes. Examples of damages and deficiencies are cracking, corrosion, voids, bond loss, reduction of cover layer, delamination, fatigue and loss of stiffness and strength. This necessitates methods to continuously assess their condition in order to avoid problems that might lead to shorter service life or reduction of structural integrity. Many of the existing prestressed bridges in Europe are now approaching their design life length. However, with proper and continuous inspection, monitoring and assessment, we may plan proactive maintenance and the structural safety can be assured or – if necessary - increased. This will save both money and decrease the environmental impact of the structure.
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| 37. |
- Atashipour, Seyed Rasoul, et al.
(författare)
-
On the Shear Buckling of Clamped Narrow Rectangular Orthotropic Plates
- 2015
-
Ingår i: Mathematical problems in engineering (Print). - : Hindawi Limited. - 1024-123X .- 1563-5147. ; 2015
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with stability analysis of clamped rectangular orthotropic thin plates subjected to uniformly distributed shear load around the edges. Due to the nature of this problem, it is impossible to present mathematically exact analytical solution for the governing differential equations. Consequently, all existing studies in the literature have been performed by means of different numerical approaches. Here, a closed-form approach is presented for simple and fast prediction of the critical buckling load of clamped narrow rectangular orthotropic thin plates. Next, a practical modification factor is proposed to extend the validity of the obtained results for a wide range of plate aspect ratios. To demonstrate the efficiency and reliability of the proposed closed-form formulas, an accurate computational code is developed based on the classical plate theory (CPT) by means of differential quadrature method (DQM) for comparison purposes. Moreover, several finite element (FE) simulations are performed via ANSYS software. It is shown that simplicity, high accuracy, and rapid prediction of the critical load for different values of the plate aspect ratio and for a wide range of effective geometric and mechanical parameters are the main advantages of the proposed closed-form formulas over other existing studies in the literature for the same problem.
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| 38. |
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| 39. |
- El Houssami, M., et al.
(författare)
-
Fire safety of interior materials of buses
- 2023
-
Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 47:7, s. 910-
-
Tidskriftsartikel (refereegranskat)abstract
- This study provides an analysis on the fire safety of passengers and the fire protection of coaches and buses. A brief review of major bus fire incidents, an overview of current regulations in Europe, and their limitations are presented. The study finds that the current small-scale fire test methods described in UN ECE Reg No. 118 need to be replaced by test methods that can assess the reaction to fire of materials when exposed to ignition sources of varying sizes. To address these shortcomings, the study proposed an expert recommendation to update the material fire safety requirements and testing for buses. Additional measures are proposed, derived from objectives and strategies applied in other transport sectors, and can be tested through existing European and international standards, which are widely used by several industries. These measures aim to extend the time with tenable conditions for a safe evacuation in case of fire, reduce the degree of damage to buses, reduce the risk for fast and excessive thermal exposure on modern energy carriers needed for a more sustainable transport sector. © 2023 The Authors.
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| 40. |
- Hagentoft, Carl-Eric, 1958, et al.
(författare)
-
Mathematical Expressions for Prediction of the Effective Thermal Conductivity of Perfectly Packed Two-phase Mixtures
- 2023
-
Ingår i: Environmental Science and Engineering (Subseries: Environmental Science). - 1863-5520. ; , s. 767-774
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces new and handy mathematical expressions for predicting and understanding the effective thermal conductivity of two-phase homogeneous mixtures. In a two-phase mixture, particles of the dispersed phase are mixed in the matrix of the second phase. A primary purpose of the proposed model is to predict and understand the effective thermal conductivity of high porous thermal insulation materials, for which many other similar analytical models offer less accuracy. The presented expressions assume a perfectly packed mixture and consider the thermal conductivity of the two phases, the proportion and the particle size of the dispersed phase. The proposed model includes non-dimensional heat loss factors, calculated by two and three-dimensional numerical simulations. In the continuation of the work presented, an experimental study is planned to evaluate the accuracy of the model, compared to other existing analytical solutions, and the validity of the assumptions made.
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| 41. |
- Johansson, Morgan, 1971, et al.
(författare)
-
Numerical modelling of vibrational effects on buildings from blasting
- 2023
-
Ingår i: 12th EFEE World Conference on Explosives and Blasting. - 9780955029080 ; :3.-Blast-Vibration-and-Seismology, s. 243-250
-
Konferensbidrag (refereegranskat)abstract
- It is well known that blasting in rock may cause structural damages to nearby buildings. There are various national standards that regulate acceptable blast induced vibration levels. These standards are sometimes criticized for being outdated with a need of revision. Such a revision should be based on deeper knowledge on the various aspects that causes damages to buildings from vibrations; either based on distance, frequency or some other measures. It is thus of importance to develop more reliable numerical predictions on ground and structural vibrations from blasting in rock, as this enables a more efficient rock excavation process that may lead to both economic and environmental savings. The present work is a continuation of [1] where numerical simulations are carried out based on the finite element method with both two-dimensional and three dimensions models. The numerical simulations have been used to carry out parameter studies on simplified buildings exposed to vibration loads. Parameters that are varied in these studies have been geometry, material and load characteristics in the form of load frequency and wave propagation speed in the ground. Comparisons are made with experiments carried out in Norway by NGI. The work concludes several features that have notable influence on the structural vibration: • The parameters and modelling related to the ground-building interaction are important: o Both vertical and horizontal coupling effects should be captured. o The damping properties of the ground-building interaction need to be taken into account. • Simplified two-dimensional models generally capture the lowest fundamental vibrational modes of the building. • Global effects (eigenfrequencies and vibrational modes) and local effects (stress concentrations near corners etc.) are coupled in an intricate manner.
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| 42. |
- Karim, Ali Naman, 1992, et al.
(författare)
-
Determination of the Effective Thermal Conductivity of Aerogel-based Coating Mortars Using Numerical Simulations- Random Packing
- 2023
-
Ingår i: Environmental Science and Engineering (Subseries: Environmental Science). - 1863-5520. ; , s. 757-765
-
Konferensbidrag (refereegranskat)abstract
- Aerogel-based coating mortars have declared thermal conductivities of 0.03-0.05 W/(m∙K), similar to those of conventional thermal insulation materials. Due to the high porosity and fragility of aerogel granules, the material obtains a reduced mechanical strength compared to conventional mortars. Recently, there has been a large research effort on developing new mixtures with improved thermal and mechanical properties. This paper presents and evaluates two-dimensional numerical simulations, based on the random packing technique, as an alternative method to laboratory measurements in predicting the effective thermal conductivity of these mortars. Experimental data from the literature, on thermal conductivity of aerogel-based coating mortars containing 50-90 vol- % aerogels were used to validate the simulation results. In this preliminary validation study, a relative error of 6-10 % was observed. Future work can focus on improving the accuracy and including the prediction of mechanical properties in the suggested model.
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| 43. |
- Karim, Ali Naman, 1992, et al.
(författare)
-
Moisture absorption of an aerogel-based coating system under different wetting scenarios
- 2023
-
Ingår i: Building and Environment. - 0360-1323. ; 245
-
Tidskriftsartikel (refereegranskat)abstract
- Aerogel-based coating mortars (ACM-systems) provide energy-efficient retrofitting solutions for masonry buildings, with thermal conductivities (30-50 mW/(m·K)) comparable to traditional insulation materials. However, limited knowledge on their moisture absorption under rainwater wetting hinders the moisture-safe design of building envelopes incorporating these mortars. Thus, this study investigated the moisture absorption of an ACM-system under three laboratory-created wetting scenarios. A small-scale setup was developed to simulate runoff wetting based on typical wind-driven rain intensities in Sweden, enabling continuous monitoring of moisture conditions during wetting and drying. Two complementary capillary suction experiments under zero (free suction) and elevated hydrostatic pressure explored additional wetting scenarios. The impact of water-repellent paint and surface cracks was also assessed, as previous testing focused on undamaged ACM-systems. Among the three wetting scenarios, runoff wetting resulted in the lowest moisture absorption by the undamaged ACM-system. Water-repellent paint (sd=0.01 m) reduced moisture uptake by up to 15% during runoff and 50% during free capillary suction for the same system. Horizontal or vertical surface cracks of 1±0.5 mm width increased water absorption by 3-5 times during prolonged runoff wetting, comparable to suction at elevated hydrostatic pressure. Furthermore, a trial was done to verify a simplified numerical moisture transport model using the runoff experiment. The results highlighted the necessity for future model refinement and advanced moisture transport modeling in the ACM-system. The developed small-scale setup facilitated easy use and real-time monitoring of moisture conditions during wetting and drying. Future development should include wind-driven rain simulation alongside the existing runoff wetting scenario.
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| 44. |
- Karim, Ali Naman, 1992, et al.
(författare)
-
Superisolerande puts ett steg närmare verklighet i Sverige – erfarenheter från fältförsök
- 2022
-
Ingår i: Bygg och teknik. - 0281-658X. ; :2, s. 46-48
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Aerogelbaserad puts skapar nya möjligheter vid energieffektivisering av putsade fasader. Detta kan ha särskild betydelse vid renovering av kulturhistoriskt värdefulla byggnader där putsen ger en energieffektivisering utan att förvanska byggnaden. Putsen kan dessutom ersätta isoleringen i fasaden och därmed minska tjockleken på konstruktionen. I ett forskningsprojekt på Chalmers testas nu materialet ur ett fuktsäkerhetsperspektiv för användning i Sverige. Denna artikel beskriver putssystemet med aerogelbaserad puts och presenterar de praktiska erfarenheterna från det första pågående fältförsöket i Sverige.
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| 45. |
- Karim, Ali Naman, 1992
(författare)
-
Wetting and drying of aerogel-based coating mortars in Swedish climates
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aerogel-based coating mortars (ACMs) have emerged as energy-efficient wall finishes with thermal conductivities of 30–50 mW/(m∙K). These coating mortars represent a promising alternative to traditional thermal insulation materials for retrofitting uninsulated building envelopes particularly in culturally significant structures. Although previously used in Central Europe, their moisture absorption under rainwater wetting, early-stage drying, and long-term hygrothermal performance in other climates remain inadequately explored. This gap in knowledge presents challenges in designing moisture-safe solutions and evaluating in-field thermal insulation performance in regions characterized by high moisture loads and limited drying potential. Therefore, an investigation was conducted to increase knowledge of the moisture performance of coating systems with ACMs. This investigation combined field and laboratory-based measurements with numerical hygrothermal simulations to study their moisture absorption under diverse wetting scenarios and evaluate their drying performance. Furthermore, the impact of surface water-repellent properties and surface cracks was assessed. The laboratory studies employed a newly developed small-scale test setup designed to simulate runoff wetting caused by typical wind-driven rain intensities in Sweden. Moreover, two supplementary capillary suction experiments under zero (free suction) and elevated hydrostatic pressure (created by Karsten tube) were conducted to explore additional wetting scenarios. A 15-month field test in Gothenburg, Sweden, combined with hygrothermal simulations were utilized to evaluate the early-stage drying and long-term hygrothermal performance of the coating system with ACM for four Swedish cities. The laboratory measurements demonstrated minimal moisture absorption in the undamaged coating system with ACM, even during prolonged 24-h runoff wetting. As expected, applying water-repellent paint (sd = 0.01 m) to the exterior of the coating system effectively reduced the water absorption while maintaining the drying capacity. Conversely, coating systems with a 1 ± 0.5 mm wide surface crack had 3–5 times amplified water intrusion due to hydrostatic pressure from the created water film on the surface. This could increase the risk of local moisture accumulation. Capillary suction tests of the ACM revealed a substantial increase in water absorption after repeated wetting exposure. Meanwhile, the same tests on the complete coating system showed a consistently stable water absorption. Field measurements indicated that the built-in moisture in the ACM dried out within six months. Hygrothermal simulations for four Swedish cities revealed an early-stage drying period ranging from 134 to 336 days based on the climate and time of application. Over time, the ACM exhibited no hygroscopic moisture accumulation; however, walls highly exposed to wind-driven rain could experience elevated relative humidity within the ACM, thereby resulting in an average increase in thermal conductivity of up to 9%. The findings show that the examined coating system with ACM presents a moisture-safe solution for retrofitting external homogenous concrete and masonry structures, preventing moisture accumulation from rainwater wetting. However, considering the information regarding the anticipated early-stage drying time and the moderate elevation in thermal conductivity is crucial when evaluating the in-field hygrothermal performance of the coating system.
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| 46. |
- Kruglowa, Thomas, 1979, et al.
(författare)
-
Density calibration using X-ray equipment for in-situ assessment of timber structures
- 2010
-
Ingår i: 11th World Conference on Timber Engineering 2010, WCTE 2010. - 9781622761753 ; 1, s. 81-89
-
Konferensbidrag (refereegranskat)abstract
- Wood density is related to several properties that have a large influence on its quality. In this article, an X-ray image calibration procedure is presented which allows the determination of density properties for in-situ assessment of timber structures. This non-destructive method is useful for evaluation of the internal condition for global assessment of the structure. The density calibration method of X-ray images was verified on a timber beam specimen with good agreement and an average accuracy of 97%. The values obtained from the image calibration presented very good linear correlation coefficients (R2) between the measured density and the greyscale from X-ray images ranging from 0.90-0.98. Besides the opportunity of determining mechanical properties of timber, its main advantage over conventional techniques is the detection and quantification of internal damage, defects, disturbances and deterioration that reduce mechanical properties of the structure. Furthermore, this study indicates a good opportunity for the development of a successful future tool for in-situ assessment of timber structures and can also be used in the analysis of the structural behaviour.
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| 47. |
- Nikoleris, Alexandra, et al.
(författare)
-
Vem ska göra gruppindelningen och hur?
- 2012
-
Ingår i: 7:e Pedagogiska Inspirationskonferensen 2012. - 2003-3761 .- 2003-377X.
-
Konferensbidrag (refereegranskat)abstract
- Grupparbeten utmålas som pedagogiskt fördelaktiga och av Högskoleförordningen följer, att sådana är ett viktigt inslag i civilingenjörsutbildningen. Artikeln presenterar fallgropar och svårigheter som kan aktualiseras liksom ett antal faktorer som är väsentliga vid gruppsammansättning och examination för att optimera det aktiva lärande som ett grupparbete kan bidra till.
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| 48. |
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| 49. |
- Tran, Anh Tuan, et al.
(författare)
-
Resistance of cold-formed high strength steel angles
- 2019
-
Ingår i: Advanced steel construction. - : The Hong Kong Institute of Steel Construction. - 1816-112X. ; 15:3, s. 242-251
-
Tidskriftsartikel (refereegranskat)abstract
- This paper describes a study of the behaviour of cold-formed high strength steel angles. Thirty-six specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160°, and 170°) and different thicknesses (4 mm and 6 mm) were considered. The initial geometric imperfections of the specimens were determined using the 3D laser scanning method. The magnitudes of these geometric imperfections for torsional and torsional-flexural buckling and flexural buckling analyses were proposed. The commercial finite element analysis (FEA) programme ABAQUS with shell elements S4R was used for finite element analyses. Different material strengths in corner and flat parts along with different proof stresses (0.2%, 0.01%, and 0.006%) were considered in the numerical models. The experimental and FEA results showed good agreement. Influence of cold-formed angle on non-dimensional slenderness and reduction factor curves of the 4 mm thick columns with 90° and 120° cold-formed angles was analysed.
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| 50. |
- Tuovinen, Heimo
(författare)
-
Simulation of Combustion and Fire-Induced Flows in Enclosures
- 1995
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Numerical modeling of combustion in flames and gas flows and gas flows generated by fires in compartments has been carried out. The laminar flamelet model has been used to model combustion in different degrees of vitiation in order to model fire gas recirculation which occurs in compartment fires. CFD modeling (computational fluid dynamics) has been used in the calculation of the flow field. The flamelet calculations were carried out using a modified version of the Cranfield SNECKS code and CFD calculations using the Fire Research Station’s JASMINE code. The results from both flamelet and CFD calculations agree reasonably with experimental results. Generally, the deviations from laboratory measurements are less than 30%, which is not greater than the errors expected in the measurements.
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