Change search
Refine search result
1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Johnsson, Helena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Parida, Gabriela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Prediction model for the load-carrying capacity of nailed timber joints subjected to plug shear2013In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 46, no 12, p. 1973-1985Article in journal (Refereed)
    Abstract [en]

    Timber joints can experience ductile failures as modeled by Johansen in the European Yield Model adapted in Eurocode 5, or they can fail in a brittle manner. In nailed or screwed joints where the fastener does not protrude through the timber, plug shear failure can occur where an entire plug defined by the perimeter of the joint is torn away from the timber. The brittle plug shear failure, which can occur in joints loaded in tension parallel to the grain, results in a lower joint resistance than the ductile failure modes. The aim of this study is to evaluate existing prediction formulas for plug shear failure in timber connections, compare them to test results and observations, and propose a new prediction formula. Test results from four different experimental studies are presented. Using hypothesis testing, a prediction formula for plug shear failure is proposed based on 92 experiments. The resistance of the tensile failure mode of plug shear failure is best modelled by the tensile resistance of the end face of the plug. The resistance of the shear failure mode of plug shear failure is best modelled by the shear resistance of the bottom area of the plug taking into account the volume effect on shear strength. The model currently in Annex A of Eurocode 5 is overestimating the plug shear resistance compared to the test results analysed in this research. To avoid plug shear failure, short and wide joints are preferred, minimising the number of fasteners in line with the load and grain direction

  • 2. Johnsson, Helena
    et al.
    Tlustochowicz, Gabriela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Vilken skillnad gör en skiva?2010In: Samhällsbyggaren, ISSN 2000-2408, no 2, p. 16-18Article in journal (Other (popular science, discussion, etc.))
  • 3.
    Lidelöw, Helena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Parida, Gabriela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Girhammar, Ulf Arne
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Åhlén, Johan
    Moelven Töreboda, Sverige.
    Projekt: Pelar-balksystem för höga trähus2010Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Syftet med projektet är - att utveckla en optimeringsmetod för pelar-balksystem i limträ som tar hänsyn till fenomenen i både bruks- och brottgränstillstånd och - att undersöka hur optimeringsmetoder kan användas i projekteringsskedet för flervåningshus i trä. 

  • 4.
    Parida, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Fragiacomo, Massimo
    Department of Architecture, Design and Urban Planning, Faculty of Architecture, University of Sassari.
    Johnsson, Helena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Prefabricated timber walls anchored with glued-in rod connections: racking tests and preliminary design2013In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 71, no 5, p. 635-646Article in journal (Refereed)
    Abstract [en]

    A new beam and post system for multi-storey timber buildings is being developed in Sweden. The stabilising walls are constructed from two Kerto-Q LVL boards glued and screwed onto a glulam skeleton. The walls are prefabricated off-site and connected to the foundation using either glued-in rods or nail plates.An introductory racking test of a full scale stabilising wall anchored with glued-in rods was performed. The paper presents the results of the experimental test and evaluates them using the transformed section method. To evaluate the strength of the glued-in rods, two newly proposed models were employed. A theoretical examination was conducted to investigate the role of the sheathing in the racking load carrying capacity. An analysis was also performed to quantify the contribution of the axial force on the racking capacity of the wall, which was conservatively ignored in the experiment. Generally, the stabilising wall panels tested in this experimental programme showed high strength and stiffness. The anchoring joints with glued-in rods demonstrated a high load-carrying capacity, however, with a large scatter and a brittle failure mode characterized by pull-out from the timber member. The transformed section method is recommended as a method for designing stabilising walls anchored with glued-in rods.

  • 5.
    Parida, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Johnsson, Helena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Fragiacomo, Massimo
    Department of Architecture, Design and Urban Planning, University of Sassari.
    Provisions for ductile behavior of timber-steel connections with multiple glued-in rods2013In: Journal of Structural Engineering, ISSN 0733-9445, E-ISSN 1943-541X, Vol. 139, no 9, p. 1468-1477Article in journal (Refereed)
    Abstract [en]

    Connections with glued-in rods are very efficient and high strength joints, and can be successfully used for e.g. anchorage of vertical timber elements to the foundation. Although extensive research was done on the pull-out strength of single rods, few references can be found on the behavior of multiple glued-in rods. This paper presents the results of an experimental program carried out on timber-to-steel connections with multiple glued-in rods. Two series of ten specimens with four large-diameter glued-in rods made from mild steel (series GB) and ten specimens with twelve small diameter high grade glued-in rods (series GS) were tested to failure under monotonic tensile load. Both types of connections failed ultimately in a brittle manner, however series GB developed some plastic deformations prior to failure by pull-out of two rods and longitudinal splitting of the timber member. By comparing the experimental results with the analytical predictions, no significant group effect could be detected in test series GB, and an overall acceptable approximation was found. In test series GS, no final conclusion on group effect could be drawn as several rods failed by nut stripping. A parametric study using analytical formulas was carried out to investigate the effect of rod strength, rod diameter, glued length, and timber density on the connection performance. Based on the results of the parametric study and experimental tests, it can be concluded that the use of mild steel as well as more rods of larger diameter properly spaced from each other and from the edges are all effective measures to increase the connection ductility. Furthermore, by leaving a suitable length of rod unbonded between the steel plate and the glued length, it is possible to control ductility, providing all brittle failure modes have higher strength capacity than the rod yielding force. Special care should be taken during the manufacturing process to ensure good quality of gluing (required glued length and amount of adhesive) and rod alignment.

  • 6.
    Tlustochowicz, Gabriela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Racking behaviour of stabilising walls and the anchorage systems for beam and post system in timber: Test report2010Report (Other academic)
    Abstract [en]

    This report presents the laboratory racking load tests on special composite stabilising wall elements as parts of a beam-and-post system called trä8 developed by the Swedish glulam manufacturer Moelven Töreboda. The wall elements comprise of glued laminated timber as framing members and Kerto-Q laminated veneer lumber as double-sided sheathing. The tests were performed on full-scale specimens. Two series of tests were carried out with three specimens each, where the series represented samples with two different anchorage systems, one using a special anchorage device including glued-in rods anchored to the foundation via a steel I-beam and the other using nail plates. The racking load was applied in both directions (by pushing and pulling, respectively) to enable tensile testing of the anchorage device at each bottom end of the wall element. The objectives of the testing were to evaluate the efficiency of the wall elements including the anchorage devices, and the detailed racking behaviour of the wall used as stabilising walls, both with respect to the ultimate and serviceability limit states. Thus, the stiffness, displacements and the shear capacity of the wall elements were evaluated together with their failure modes. Especially, the behaviour of the anchorage connections subjected to tensile uplifting forces was studied. The test results indicate a strong potential for using these composite stabilising wall elements for stabilising purposes in multi-storey timber buildings, and they also indicate good performance of both tested anchorage types. Future studies on the stabilising wall system would include further development and optimization of the anchorage connections, both with respect to the load capacity and the ductility of the joint.

  • 7.
    Tlustochowicz, Gabriela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Stabilising system for multi-storey beam and post timber buildings2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    For multi-storey timber buildings, the stabilisation against horizontal loads is one of the key issues, which becomes more severe with height. There are a few main concepts utilised to resist lateral forces; shear wall action, diagonal bracing, and frame action. This doctoral thesis addresses the stabilising system of a beam and post system where the main load carrying members are connected in a pinned manner and horizontal stabilisation is provided by special stabilising walls. The system ‘trä8’ developed by Moelven Töreboda AB has been studied as an example of such a system. The stabilising elements are prefabricated panels made of a glued laminated timber frame and cross-laminated veneer lumber Kerto-Q sheathing glued-screwed to the frame.The stabilising elements were examined in full-scale racking monotonic experimental tests. It was shown that prefabricated stabilising walls are very strong and stiff structures and can be successfully used for stabilisation of multi-storey timber buildings; however they require a reliable connection to the foundation. Connections with glued-in steel rods offer high strength and stiffness and were proposed as anchorage devices. They were tested both in the full-scale racking test and in single joint tensile tests. The experiment showed that these connections possess large load-carrying capacity and stiffness, but they fail typically by brittle pull-out of the rod from the timber member. A literature study was conducted to review existing manufacturing methods, mechanisms and parameters governing the performance and strength of the joints, theoretical approaches for the analysis of glued-in rods connections and existing design recommendations. Based on this review, the most recent methods were chosen to determine the pull-out capacity of glued-in rods connections and evaluate the test results. Additionally, the transformed section method was also found to be applicable for analysing stabilising walls anchored with glued-in rods connections. Brittle failure modes should be avoided in the design; therefore findings of the literature review were utilized in an attempt to achieve ductile behaviour of connections with glued-in steel rods. Two configurations of timber-to-steel connections with multiple glued-in steel rods, with many small diameter rods of high strength and few large diameter mild steel rods were tested in tension up to failure. The results showed that ductile behaviour can be achieved with mild steel rods and the number of rods should be small to reduce the amount of work during production and to reduce risk for manufacturing errors. The rods should be equally distributed in the timber cross-section to optimize the load transfer. At the current state, the only thing that seems to prevent a design method for the design of glued-in rod connections in Eurocode 5 is a proper estimation of the characteristic shear strength value.The full-scale racking test also included nailed hold-downs. For large nailed connections loaded in tension parallel to the grain, an increased risk for plug shear failure exist, which was observed in the racking experiment. Nailed connections in general have a lower stiffness than glued-in rods connection provided they have the same connection area. The results of this test contributed, together to those of a previous study, to check the design proposal in Eurocode 5 for shear plug failure capacity of nailed connections, which was found to be non conservative.

  • 8. Tlustochowicz, Gabriela
    Stommontaget av ett demonstrationshus byggt i pelar-balk system i limträ2008Report (Other academic)
    Abstract [en]

    Beam and post system has a number of advantages as simplicity and flexibility, and freedom in architectural design. This system, also called skeleton frame system has a long history in housing, but since the world is dominated by tendency optimization and economization the heavy solid timber structures for houses applies just for individual projects, mostly for aesthetical reasons. Since the beam and post system is effective and competitive for large spans, the system requires large dimensions of members. Glued laminated timber with higher strength parameters is more suitable for this system and that is why it became an object of interest of Moelven Töreboda AB.The company Moelven Töreboda AB took a first step towards wider use of beam and post system in timber housing by building a demonstration house with the use of glulam and Kerto LVL boards . The erection of the building was a subject to a detailed study during my presence on the building-site for a period of seven working weeks and the result of this work is presented in this report. The study method was observation and interviews, and the data was preserved in form of photographs and notes, and processed afterwards.The report is an introductory work to the research on optimization of a beam and post system in timber. The project is a result of cooperation between Luleå University of Technology and Moelven Töreboda AB. The long-perspective aim of the project is a development of an optimizing method for timber houses, which can be applied in the design stage.

  • 9.
    Tlustochowicz, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Johnsson, Helena
    Displacements in the stabilizing system of a glulam beam-and-post system2008In: Proceedings of the 10th World Conference on Timber Engineering: WCTE 2008 : Miyazaki, Japan, June 2-5, 2008, 2008, Vol. 3, p. 1573-1580Conference paper (Refereed)
    Abstract [en]

    The provisions for developing a beam-and-post building system of glulam are examined for the Swedish market. The building system should provide open spaces through long-span floors combined with apartment floors, reaching a total height of 5-6 stories. Building multi-storey houses in timber requires a strong and stiff stabilizing system assuring safety and comfort for their users. Large movements are unacceptable risking damage on interior claddings and even nausea with the inhabitants on the upper floors. Stabilization can be achieved through diagonal bracing, moment stiff connections or diaphragm action. In this work a special stabilizing element based on diaphragm action is proposed. A parametric study of the stabilization system against lateral loads for a beam-and-post building system is presented based on traditional and numerical analyses. The aim of the paper is to establish the limitations for the stabilizing element to function within a multi-storey beam-and-post system. The study is a first step towards introducing an optimized beam-and-post building system in timber to the Swedish market.

  • 10.
    Tlustochowicz, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Johnsson, Helena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Girhammar, Ulf Arne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Beam and post system for non-residential multi-storey timber buildings: horizontal stabilising system2010In: 11th World Conference on Timber Engineering 2010, Red Hook: Curran Associates, Inc., 2010, Vol. 4, p. 3426-3433Conference paper (Refereed)
    Abstract [en]

    Due to changes in the Swedish design code in 1994, timber construction is no longer limited to two-storey buildings. This change has created an attractive market for multi-storey timber structures. A Scandinavian glulam manufacturer, Moelven Töreboda, started in 2007 to develop a new beam and post building system in timber for multi-storey buildings with the Swedish commercial name, “trä8”. For “trä8”, the stabilising system is based on prefabricated wall panels placed at a few locations in the building. The stabilising elements consist of double sheathing of LVL Kerto-Q boards glued and screwed to a glulam frame. The panels are typically of 2.4 m width and continuous up to four storey height. The elements are fixed to the foundation by using special anchoring devices, which include threaded rods glued-in lengthwise in the timber member. In this paper, an introductory experimental study of the efficiency of this prefabricated wall panel used as a stabilising element is reported. Experimental results from full-scale testing of the racking performance of the stabilising element including the anchoring device are presented. The study, which focuses on the stiffness and the serviceability state, demonstrates that the presented wall panel elements, as part of a beam and post system for multi-storey buildings, have the potential to provide the necessary horizontal stability for the building.

  • 11.
    Tlustochowicz, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Kermani, Abdy
    Centre for Timber Engineering, Edinburgh Napier University.
    Johnsson, Helena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Beam and post system for non-residential multi-storey timber buildings: conceptual framework and key issues2010In: 11th World Conference on Timber Engineering 2010, Red Hook: Curran Associates, Inc., 2010, Vol. 3, p. 2032-2037Conference paper (Refereed)
    Abstract [en]

    In Sweden, there has been a long tradition of using timber in the construction of housing and in recent years, timber structural systems are increasingly used in multi-storey and large span buildings. The main focus of the majority of timber construction industries has been the development and utilisation of components, systems and construction techniques for the large market of residential buildings. Moelven Töreboda AB, a Scandinavian glulam manufacturer, has developed a beam and post system named “trä8” with the intention of filling the gap in the market for non-residential multi-storey buildings in timber. The developed timber beam and post system offers many advantages over other construction systems as well as being an attractive and versatile system for meeting clients’ and users’ expectations. This paper examines and provides guidelines on key issues in the development of the timber beam and post system for multi-storey non-residential buildings and deals with its structural system, assembly method and weather protection.

  • 12.
    Tlustochowicz, Gabriela
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Serrano, Erik
    School of Engineering, Linnæus University, Växjö.
    Steiger, René
    Applied Wood Materials Laboratory, Swiss Federal Laboratories for Materials Science and Technology (EMPA), CH-8600 Dübendorf.
    State-of-the-art review on timber connections with glued-in steel rods2011In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 44, no 5, p. 997-1020Article in journal (Refereed)
    Abstract [en]

    Adhesive joints have been known and applied for timber structures for decades. Hybrid joints with glued-in rods are nowadays successfully used for both constructing new and strengthening existing timber structures. Since the 1980s the research and development of timber joints with bonded-in rods have been going on, however agreement regarding design criteria for these connections has not been reached. Today, connections with glued-in rods are not included in the European design code. Thus, it is desired to gather the current state of knowledge to enable application in practice of the existing and documented knowledge and experience. This paper summarizes practical and theoretical approaches from research done regarding joints with glued-in steel rods mostly in Europe and published in English, German or Swedish. The review considers manufacturing methods, mechanisms and parameters governing the performance and strength of the joints, theoretical approaches and existing design recommendations

1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf