| 1. |
- Abrahamsen, Rune, et al.
(författare)
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Dynamic Response of Tall Timber Buildings Under Service Load : The DynaTTB Research Program
- 2020
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Ingår i: EURODYN 2020, XI international conferece on structural dynamics. - : National Technical University of Athens. - 9786188507210 ; , s. 4900-4910
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Konferensbidrag (refereegranskat)abstract
- Wind-induced dynamic excitation is becoming a governing design action determin-ing size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway – i.e. vibration serviceability failure. Although some TTBs have been instrumented and meas-ured to estimate their key dynamic properties (natural frequencies and damping), no systematic evaluation of dynamic performance pertinent to wind loading has been performed for the new and evolving construction technology used in TTBs. The DynaTTB project, funded by the Forest Value research program, mixes on site measurements on existing buildings excited by heavy shakers, for identification of the structural system, with laboratory identification of building elements mechanical features coupled with numerical modelling of timber structures. The goal is to identify and quantify the causes of vibration energy dissipation in modern TTBs and pro-vide key elements to FE modelers.The first building, from a list of 8, was modelled and tested at full scale in December 2019. Some results are presented in this paper. Four other buildings will be modelled and tested in spring 2020.
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| 2. |
- Abrahamsen, Rune, et al.
(författare)
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Dynamic response of tall timber buildings under service load : results from the dynattb research program
- 2023
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Ingår i: World Conference on Timber Engineering 2023 (WCTE 2023). - : Curran Associates, Inc.. - 9781713873297 ; , s. 2907-2914
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Konferensbidrag (refereegranskat)abstract
- Wind-induced dynamic excitation is a governing design action determining size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway, i.e. vibration serviceability problem. Although some TTBs have been instrumented and measured to estimate their key dynamic properties (eigenfrequencies, mode shapes and damping), no systematic evaluation of dynamic performance pertinent to wind loading had been performed for the new and evolving construction technologies used in TTBs. The DynaTTB project, funded by the ForestValue research program, mixed on site measurements on existing buildings excited by mass inertia shakers (forced vibration) and/or the wind loads (ambient vibration), for identification of the structural system, with laboratory identification of building elements mechanical features, coupled with numerical modelling of timber structures. The goal is to identify and quantify the causes of vibration energy dissipation in modern TTBs and provide key elements to finite element models. This paper presents an overview of the results of the project and the proposed Guidelines for design of TTBs in relation to their dynamic properties.
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| 3. |
- Alen, Malagic, et al.
(författare)
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Reinforced notched cross-laminated timber plates : Load-bearing capacity and methodology for predicting the force in reinforcement
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873273 - 9781713873297 ; , s. 2442-2453
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the estimation of the design force in self-tapping screws used as a reinforcement ofnotched cross laminated timber plates (CLT). With the reinforcement, apart from an increased load-carrying capacity, amore ductile behaviour of this detail can be achieved. An analytical model based on the Timoshenko Beam Theory wasdeveloped, enabling the estimation of the axial force in the reinforcement. A parametric numerical analysis was conductedto verify the model and to provide possible ways for the calibration. The results show a good matching of the model withthe numerical results. The load-bearing capacity is analysed using a simple fracture mechanics model taking intoconsideration the effect of the reinforcement to correctly depict the increase in performance. Theoretical and numericalresults are compared with experimental findings and show acceptable correlations encouraging a further development anda subsequent implementation in EN 1995-1-1.
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| 4. |
- Azinović, Boris, et al.
(författare)
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INNOCROSSLAM : Adding knowledge towards increased use of cross laminated timber (CLT)
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873297 - 9781713873273 ; , s. 2432-2441
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Konferensbidrag (refereegranskat)abstract
- The research project Innovative Solutions for Cross Laminated Timber Structures (InnoCrossLam) wasrecently finished. The project aimed at increasing the competitiveness of CLT as a versatile engineered product, byincreasing its predictability in demanding design situations not covered by the guidelines of today, or standards and codesforeseeable in the near future (e.g., second generation of European design standards). This paper summarises the mainproject findings in the context of innovative CLT structures, such as: i. contemporary design approaches ii. the use of(non)linear FE modelling iii. experimental investigation of complex details for CLT structures, iv. investigation ofmultifunctional CLT. In this paper, the motivation behind the research topics within the project InnoCrossLam isexplained and backed-up by exemplary results and discussion on future work.
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| 5. |
- Danielsson, Henrik, et al.
(författare)
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Shear failure mechanism III in cross laminated timber : Numerical investigations of fracture behaviour
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873273 ; , s. 2396-2405
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Konferensbidrag (refereegranskat)abstract
- The paper deals with numerical investigations of load-bearing capacity and fracture behaviour of CrossLaminated Timber at in-plane shear loading. Focus is on shear failure mechanism III, i.e. failure in the crossing areasbetween flatwise bonded laminations, and on evaluating test methods for that failure mode. In current design provisions,this failure mode is characterised by the rolling shear strength, fv,R , and the torsional shear strength, fv,tor , and thereforetesting including both transverse (rolling) shear and torsional shear is needed. Two such test set-ups are investigated, oneaiming at evaluating torsional shear strength and one aiming at evaluating rolling shear strength. Full 3D finite elementanalyses applying a cohesive zone model approach were used to study the strength and fracture behaviour. Failure criteriafor structural design, material strength parameters, and the suitability of the two test configurations to determine strengthparameters are discussed in relation to findings from the numerical investigations. One main conclusion from theinvestigation is that expected test results using the torsional test set-up are less size dependent as compared to test resultsusing the transverse set-up. The numerical analyses suggest a very small influence from tensile loading perpendicular tothe crossing area, for both test set-ups.
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| 6. |
- Mohaine, Siyimane, et al.
(författare)
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PERFORMANCE OF PASSIVE PROTECTION OF CROSS LAMINATED TIMBER DURING STANDARD FURNACE TESTS AND NATURAL FIRES
- 2023
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Ingår i: 13th World Conference on Timber Engineering, WCTE 2023. - 9781713873297 ; 3, s. 1839-1847
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Konferensbidrag (refereegranskat)abstract
- This paper presents the results of an experimental campaign designed to compare and understand the performance of passive protection under exposure to standard furnace tests and natural fires. As part of this campaign, five natural fire experiments were performed with partially protected cross-laminated timber (CLT) compartments under a range of ventilation conditions. In all the tests, only one side wall was left completely unprotected, and all other timber surfaces were protected with either two layers of 18 mm standard gypsum boards (GB) or two layers of 25 mm standard GBs. The structural CLT ceilings were subjected to a superimposed dead load of 1.35 kN/m² during the natural fire tests, and the fire load was (on average) 950 MJ/m²; chosen to represent the Eurocode 1991-1-2 characteristic value for dwellings. The performance of the passive protection was mainly evaluated with regards to the time to reach a protected timber surface temperature of 250°C. The testing confirms that the resulting fire protection performance of a given gypsum board layout depends on the ventilation conditions of the fire compartment, with more severe (and closest to ISO testing) outcomes when testing under ventilation-controlled scenarios. This paper provides data that sheds light on the co-dependency of the passive protection design and compartment fire dynamics and underlines the importance of considering the safety objectives of a building when defining the performance criteria of its structural elements.
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| 7. |
- Pousette, Anna, et al.
(författare)
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Durable Timber Bridges - Final Report and Guidelines
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This is the final report from the project DuraTB - Durable Timber Bridges. The goal of the project was to contribute to the development of sustainable timber bridges by making guidelines for moisture design and developing new and improved bridge concepts and details in terms of durability and maintenance aspects.In this report the analyzes, surveys, results and guidelines are described. More detailed descriptions are referred to the many publications that the project has delivered.The research leading to these results has received funding from the WoddWisdom-Net Research Programme which is a transnational R&D programme jointly funded by national funding organisations within the framework of the ERA-NET WoodWisdom-Net 2.
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| 8. |
- Robert, Fabienne, et al.
(författare)
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NATURAL FIRE TESTS ON GLT COLUMNS INCLUDING THE COOLING DOWN PHASE
- 2023
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Ingår i: 13th World Conference on Timber Engineering, WCTE 2023. - : World Conference on Timber Engineering (WCTE). - 9781713873297 ; 3, s. 1848-1854, s. 1848-1854
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Konferensbidrag (refereegranskat)abstract
- This paper presents the data and the results of seven fire tests performed on glue laminated timber columns in a compartment built especially for the tests and in which timber wood cribs created a so-called natural fire. These tests are part of a research programme titled "burnout resistance" to establish a new methodology to better describe performance of structural elements during the whole duration of a fire. Comparisons with similar tests made in a fire resistance furnace allow comparing charring rates observed in standard conditions and in natural fires.
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