| 1. |
- Magnusson, Johan, et al.
(författare)
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Air-blast-loaded, high-strength concrete beams. Part II : Numerical non-linear analysis
- 2010
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Ingår i: Magazine of Concrete Research. - : Thomas Telford Ltd.. - 0024-9831 .- 1751-763X. ; 62:4, s. 235-242
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Tidskriftsartikel (refereegranskat)abstract
- The results from this investigation demonstrate the ability to perform numerical simulations of dynamic structural response of concrete elements subjected to air blast loading. Beams of both high-strength concrete (HSC) and normal-strength concrete (NSC) were studied. Also beams with two concrete layers of different strength were simulated. It is of particular interest to investigate the use of material models for implementation with software for the explicit analysis of non-linear dynamic events. The influences of concrete strength, amounts of reinforcement, the bond between concrete and reinforcement, bi-linear strain softening of concrete, the strain rate dependence of reinforcement and boundary conditions at the supports were studied. The simulations were performed with the text data as reference through comparison between numerical examples and experimental test results. It was possible numerically to analyse the dynamic behaviour of beams tested in situ and to describe the observed failure modes of these beams. The analysis tool will be used for evaluating the dynamic strength of future protective structures of HSC, possibly with parts consisting of NSC elements.
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| 2. |
- Schönbeck, Pia, et al.
(författare)
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A decision support model for hospital configurations in construction projects
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Hospitals are complex buildings and their functionality is essential for patient healthcare. Definition, verification and implementation of accurate configuration information during construction projects are therefore essential. The purpose of this study was to develop a decision support model by establishing a value chain of configuration information with an end-to-end perspective. The approach of this study was explorative, investigating how building data can support construction projects in making hospital configuration decisions. A literature review provided a knowledge base about the configuration decision process, which determined the entities and composite attributes for the proposed database model. The possibility to extract data from building models to a database was studied by establishing relevant exchange schemas. A case study compared the IFC schemas from three construction projects of Magnetic Resonance Imaging rooms to the database model. The results show that using building model data for decision support is feasible. In the cases studied, there were operational gaps compared to the model regarding data availability about object relationships, processes and resources. This shows a need for change in current data collection and management. The contribution of this study is filling a research gap regarding end-to-end information management to support hospital configuration decisions in construction projects.
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| 3. |
- Johansson, Morgan, 1971, et al.
(författare)
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Inventering av kunskapsbehov i byggbranschen med hänsyn till explosioner i en förtätad stadsmiljö
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Med syfte att frigöra attraktiv markyta för vidare bebyggelse finns det på många orter idag ett önskemål att genomföra en förtätning av den befintliga stadsmiljön. En sådan förtätning resulterar dock i minskade avstånd mellan byggnader och transportled, vilket medför ökade krav med hänsyn till bland annat explosioner. Hantering av explosioner i en förtätad stadsmiljö kan övergripande sägas bestå av tre delområden – riskhantering, explosionslast samt strukturrespons. I en explosionssituation har alla dessa delområden en avgörande inverkan på den slutliga utformningen av närliggande byggnader och för att erhålla en bra helhetslösning krävs att delområdena hanteras som en sammanhängande enhet. Detta gör att problematiken blir tvärvetenskaplig och därmed också mer komplex. I dagens hantering av explosioner finns det dock bety-dande brister inom samtliga delområden, något som till stor del beror på att kompe-tensen om explosioner i byggbranschen är otillräcklig. Ett övergripande syfte med detta arbete har varit att bidra till en ökad nationell kom-petens om explosioner samt explosionsbelastade strukturer. Detta har gjorts genom att inventera och sammanställa aktuella frågeställningar, behov samt specifika tillämp-ningsområden som för branschen är kopplade till explosioner i en tät stadsmiljö. Målet med arbetet har varit att skapa ett underlag för ett framtida, större samverkans-projekt, vilket närmare kan studera hur identifierade frågeställningar bör hanteras. Arbetet har genomförts via en kombination av litteraturstudier och intervjuer. De senare har utgjort en central del av arbetet och dessa har genomförts med personer av varierande bakgrund i byggbranschen, vilka på olika sätt har en nära anknytning till explosioner i en förtätad stadsmiljö. Som komplement till detta presenteras även författarnas funderingar kring frågor kopplade till explosionslast och strukturrepsons. Av utförd inventering kan konstateras att det råder konsensus bland de intervjuade om att det i branschen finns ett stort behov av ökad kunskap om explosioner. Vilka behov som identifieras varierar dock eftersom de intervjuade har olika roller. Ett samstäm-migt önskemål finns dock i form av att en branschgemensam handbok bör tas fram som kan användas som stöd vid hantering av explosionsbelastning. En viktig uppgift för en sådan handbok blir då att främja samverkan mellan olika kompetenser kring explosion – särskilt den mellan riskanalytiker och konstruktör – samt att den bidrar till en ökad koppling mellan explosionslast och konsekvens mot omgivningen. Hand-boken behöver vidare behandla samtliga delområden och kan lämpligen ges ut av Trafikverket i en form liknande den som Trafikverkets projekteringshandböcker.
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| 4. |
- Larsson, Stefan, et al.
(författare)
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Finite element modelling of laterally loaded lime-cement columns using a damage plasticity model
- 2012
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Ingår i: Computers and geotechnics. - : Elsevier BV. - 0266-352X .- 1873-7633. ; 44, s. 48-57
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Tidskriftsartikel (refereegranskat)abstract
- The behaviour of laterally loaded lime-cement columns in a shear box was studied. Laboratory tests are presented together with numerical analyses where the columns are simulated by a concrete damage plasticity model that considers stiffness degradation. Seven model tests were investigated where the columns were installed in a single column pattern and in rows with different column overlap in order to investigate the influence of the degree of overlapping of the columns in the rows. The results of the numerical evaluations showed good agreement with the experimental shear stress-displacement relation and a good accuracy with respect to the fractures developed.
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| 5. |
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| 6. |
- Schönbeck, Pia, et al.
(författare)
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Potential of automated configuration control to reduce hospital building deficiencies
- 2022
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Ingår i: Procedia Computer Science. - : Elsevier BV. ; , s. 61-68
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Konferensbidrag (refereegranskat)abstract
- The configuration of healthcare buildings is complex, especially emergency hospitals that require many functions. In this study, the aim was to explore if automated configuration control can reduce occurrences of hospital deficiencies in construction projects. A bow-tie risk analysis identified the causes and consequences of configuration deficiencies. Measures to prevent and recover from deficiencies were established from configuration management research. Three newly built emergency hospitals were studied to investigate to what extent causes, consequences, preventive and recovery measures were present. The most common causes of deficiencies were deviations from intended configurations, in the literature and the cases. The consequences were cost increase, time delays, insufficient deliveries and corrective rework. None of the examined cases had implemented preventive or recovery measures associated with configuration control. Altogether, these results indicate that automation of configuration control may effectively reduce hospital building deficiencies and subsequent effects.
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| 7. |
- Schönbeck, Pia
(författare)
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Data based configuration decisions in hospital construction projects
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of hospital buildings is to enable the diagnosis, treatment and caring of patients. Hospital configurations are therefore complex and deficient functionality at the final delivery of construction projects are a known issue. Configuration management is essential to ensure that all required functions are fulfilled. Digital building model data can provide the necessary information to support management of hospital configurations. Data based decisions are dependent on a baseline that contains all required functions. Thereafter, connections between data regarding functions, solutions and production methods should be established. This knowledge provides opportunities for automated data analyses giving real time accurate configuration information, enabling the prevention of deviations from the client’s intent and streamlining processes. The studies in this compilation thesis investigate this subject from different perspectives. Literature reviews, case studies and quantitative analyses of digital building data were the methods used. The results show that the systematic management of data and information can ensure hospital configurations that fulfil required functions at handover. These studies provide a conceptual model showing how configuration information applies to the construction project processes. The proposed detailed decision model shows how data from building models can support hospital configuration decisions in construction projects. Studies show that hospital construction projects management of configuration changes information is deficient. Manually managed logs contained insufficient information about the changes, while the building model data unused by the investigated projects was significantly more reliable. A risk analysis shows that data based configuration decisions in construction projects can prevent hospital building deficiencies, or facilitate recovery if they have already occurred. Digital technologies can improve the accuracy of configuration information, on which automated and industrial production equipment are dependent. However, construction project research seldom addresses the potential synergy and sustainability effects of different technologies. All case studies performed show that the current configuration information management in hospital projects is incomplete. Consequences found were cost increase, delays, reduced client value and corrective rework. The overall conclusion is that data based decisions can improve the control over hospital configurations, ensuring healthcare functions, construction project outcomes and sustainability. This thesis identifies a new research field by showing the potential of data based configuration decisions.
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| 8. |
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| 9. |
- Gasch, Tobias, et al.
(författare)
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Cracking in Quasi-Brittle Materials Using Isotropic Damage Mechanics
- 2016
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Konferensbidrag (refereegranskat)abstract
- An extension of the Solid mechanics interface in Comsol Multiphysics is presented to analyse localized deformations of quasi-brittle materials, for example cracking in concrete. This is achieved by implementing an isotropic damage mechanics constitutive law, which is combined with both a local and a non-local regularization technique to ensure mesh objectivity. The implementation is made using equation based modelling and modification of built-in features. To facilitate easier use of the model, a custom user interface is constructed using the Physics Builder. Lastly, the implemented model is validated using examples of both plain and reinforced concrete, with two examples taken form the literature. Overall the simulation results are in good agreement with the experimental observations.
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| 10. |
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