Marie Johansson

Marie Johansson
RISE Research institute of Sweden · Wood building technology

PhD

About

56
Publications
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733
Citations

Publications

Publications (56)
Conference Paper
Full-text available
The height and the market share of multi-story timber buildings are both rising. During the last two decades, the Architectural and Engineering Construction industry has developed new reliable solutions to provide strength, structural integrity, fire safety and robustness for timber structures used in the mid-and high-rise sectors. According to lon...
Conference Paper
Full-text available
The presented project aims to develop prototypes for building connections inspired by the furniture and interior industry and explore them with representatives from the timber construction industry. The long-term vision is that actors from furniture and building industry together develop a smart system for assembly of building elements, which provi...
Conference Paper
Full-text available
Wind-induced dynamic excitation is becoming 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 failure. Although some TTBs have been instrumented and...
Conference Paper
Wind-induced dynamic excitation is becoming 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 failure. Although some TTBs have been instrumented and...
Technical Report
Full-text available
There is a deficit of housing in Sweden and it is built too little to compensate for this according to the National Board of Housing, Building and Planning, which, among other things, indicate resource shortages as a reason. The furniture and construction industry have much in common. However, the furniture industry has a larger share of industrial...
Article
Building with prefabricated light-frame volume modules is a prevalent and innovative construction method for low and mid-rise timber buildings. Compared to traditionally site-built constructions this method is very advantageous due to its high prefabrication level and the fast on-site assembly of the modules. The focus of this project is to study a...
Article
Full-text available
Strength of structural timber depends to a high degree on the occurrence of knots and on the local fibre deviation around such defects. Knowledge of local fibre orientation, obtained by laser scanning, has been utilized in a previously developed machine strength grading method, but rather crude assumptions regarding the fibre orientation in the int...
Conference Paper
Full-text available
When designing a tall timber building, the accelerations due to wind loads are in many cases decisive. The parameters governing the dynamic behaviour of the building are the structure's stiffness, damping and mass together with the loads. The first two parameters are not well-known during the serviceability limit state of timber structures generall...
Article
Full-text available
In breeding Norway spruce, selection for improved growth and survival is performed at age 10–15 years in order to optimize genetic gain per year. We investigated whether a selection based on wood traits such as density and grain angle, measured under bark in the field at the same age would be informative enough with respect to structural quality tr...
Conference Paper
Full-text available
Strength of structural timber depends to a high degree on the occurrence of knots and on the local fibre deviation around such defects. Knowledge of local fibre orientation, obtained by laser scanning, have been utilized in a previously developed machine strength grading method. However, that method was based on rather crude assumptions regarding t...
Article
Full-text available
The strength of structural timber largely depends on the occurrence of knots and on the local material directions in the surroundings of such knots. There is, however, a lack of methods for establishing a full dataset of the local material directions. The present research aims at the development and application of a laboratory method to assess the...
Conference Paper
Full-text available
During the last years the interest in multi-storey timber buildings has increased and several medium-to-high-rise buildings with light-weight timber structures have been designed and built. Examples of such are the 8-storey building “Limnologen” in Växjö, Sweden, the 9-storey “Stadthouse” in London, UK and the 14-storey building “Treet” in Bergen,...
Article
Full-text available
Southern Africa, and specifically its western parts is dominated by low rainfall areas, and it is expected that the rainfall in most of these parts will in future decrease further due to climate change. Woodlots of fast-growing, non-invasive tree species can provide the opportunity to produce wood and release the pressure on natural woodlands, whil...
Book
Full-text available
Förord Avsikten med Limträhandbok Del 2 är att hjälpa konstruktören att dimensionera limträkonstruktioner. I synnerhet betonas förståelsen av: • Bakgrunden för dimensionering av konstruktionssystem utförda med limträ, särskilt konstruktioner med lång spännvidd. • Bakgrunden för dimensionering av förband i konstruktionssystem utförda med limträ. Den...
Article
In the water-scarce environment of South Africa, drought-tolerant eucalypt species have the potential to contribute to the timber and biomass resource. Biomass functions are a necessary prerequisite to predict yield and carbon sequestration. In this study preliminary biomass models for Eucalyptus cladocalyx, E. gomphocephala and E. grandis × E. cam...
Chapter
Full-text available
Compression wood in softwoods and tension wood in hardwoods have properties, which adversely affect its usefulness for wood products. This chapter shows that reaction wood can be associated with many unsuitable wood properties. The results vary due to the fact that definitions about occurrence and severity of reaction wood are scarcely documented....
Article
This study evaluated the potential for the selective genetic improvement of the structural quality traits important in sawn Norway spruce (Picea abies (L.) Karst.) timber based on early and nondestructively assessed field traits. From a 34-year-old Norway spruce trial situated in southern Sweden, 401 butt logs were sampled and sawn to produce two 5...
Article
Full-text available
During the last decade, the utilization of non-contact deformation measurement systems based on digital image correlation (DIC) has increased in wood related research. By measuring deformations with DIC systems, surface strain fields can be calculated. The first aim of this study concerns the possibility to detect detailed strain fields along the e...
Article
Full-text available
Machine strength grading of structural timber is based upon relationships between so called indicating properties (IPs) and bending strength. However, such relationships applied on the market today are rather poor. In this paper, new IPs and a new grading method resulting in more precise strength predictions are presented. The local fibre orientati...
Article
Full-text available
The effect of single-side ion exchange (using a KNO3:KCl mixture) on the ring-on-ring flexural strength of float glass has been studied. Two ion exchanged series, treated at 450 and 515°C, were investigated. The ion exchanged samples showed approximately 160 respectively 100% increases in their arithmetic mean strength compared to as-received float...
Article
Strength grading of Norway spruce [Picea abies (L.) Karst.] side boards in the wet state was investigated. For a sample of 58 boards, density and dynamic modulus of elasticity in the axial direction (MOE dyn) were determined in the wet state. The boards were then split into two parts and the procedure of determining MOE dyn was repeated both before...
Article
The potential of utilizing resonance frequencies corresponding to edgewise bending modes for predicting the bending strength of timber is investigated. The research includes measurements of axial and transversal resonance frequencies, laboratory assessment of density, static bending stiffness and bending strength of 105 boards of Norway spruce of d...
Article
Full-text available
The development of twist in Norway spruce boards (Picea abies Karst.) during normal temperature kiln drying was researched. Tangentially oriented boards were sawn from diametrical radial planks, from which the basic wood properties, i.e. linear shrinkage and grain angle, were determined. The unrestrained boards were kiln dried using a selected dryi...
Conference Paper
Full-text available
The present study aims at investigating the potential of using mode shape or mode shape curvature (MSC) for detecting defects in wooden beams. It includes modal analysis, Finite Element (FE) modeling and visual scanning. An FE model was created to investigate the effect of defects of different size and location on the mode shape/MSC. The mode shape...
Article
It is not fully understood how much growth stresses affect the final quality of solid timber products in terms of, e.g. shape stability. It is, for example, difficult to predict the internal growth stress field within the tree stem. Growth stresses are progressively generated during the tree growth and they are highly influenced by climate, biologi...
Article
Full-text available
In this study, two methods for calculating the force distribution in steel-timber dowel connections subjected to a moment load was studied and compared to results from an experimental study. The first method was the traditional method for force distribution which assumes the timber and wood to act as rigid bodies while the fasteners are modelled li...
Article
The use of dynamic methods to measure resonance frequencies has the possibility to give more information about the variations in modulus of elasticity (MOE) in a board than what is currently utilized in grading. In this paper results from a study of the effect of man-made defects (holes) on the resonance frequencies of higher order modes is present...
Article
Full-text available
• The board distortion that occurs during the sawing and the drying process causes major problems in the utilisation of sawn timber. The distortion is highly influenced by parameters such as spiral grain angle, modulus of elasticity, shrinkage, growth stresses and sawing pattern. • In this study a finite element simulation of log sawing and timber...
Article
Lack of straightness in timber is the most frequent complaint regarding solid (and laminated) timber products worldwide. Nowadays, customers demand higher quality in the shape stability of wood products than they did earlier. The final distortion of timber boards is mostly caused by moisture-related stresses in wood (drying distortions) and growth-...
Article
Full-text available
The limiting factors when it comes to design of timber structures are often stiffness properties of timber products. The stiffness requirements in serviceability limit state, both short-term and longterm deformation especially in horizontal members, is a factor that often makes it necessary to increase the dimensions of the member. Both the results...
Article
The present study is a supplement to Epmeier and Kliger (2005), which investigated the effect of three different modification methods (acetylation, modification with methylated melamine resin and heat treatment in vegetable oil) on four material properties (density, modulus of elasticity (MOE), creep deflection and relative creep) and their inter-r...
Article
The mechanical and physical properties of modified wood were assessed experimentally. Timber studs with a cross-section of 45 mm x 70 mm were modified on a semi-industrial scale by four different methods: 1) acetylation (AC) with acetic anhydride; 2) modification with methylated melannine formaldehyde resin (MMF); 3) heat treatment in vegetable oil...
Article
This paper presents an analytical model for twist in timber. The model is based on calculating the twist in cylindrical shells and combining these shells to create timber studs. The shells will deform when the moisture content changes, owing to tangential shrinkage perpendicular to the fibre direction and longitudinal shrinkage parallel to the fibr...
Article
Full-text available
Warp in lumber is a serious problem for the building industry. In particular, material from small-diameter logs experiences excessive twist. This paper presents a new sawing technique to minimize the problem of twist in material from small-diameter logs. Almost all the studs sawn from small-diameter logs twist in the same positive direction. By rot...
Article
Matching timber quality with end-user requirements is a major research issue and lack of straightness in timber is the most frequent complaint worldwide. The final distortion of timber boards is caused mostly by moisture-related deformations and growth stresses that develop during growth of the tree, but how much the growth rate and growth stresses...
Article
The performance of timber studs from Norway spruce (Picea abies) in terms of shape and dimensional stability was evaluated. The shape stability studied included three modes of distortion, i.e. twist, bow and spring. The dimensional stability was assessed by measuring longitudinal shrinkage and swelling properties. The study comprised 96 studs measu...
Article
Full-text available
Straightness is one of the most important properties for making timber an attractive material for modern mechanized building. Several studies have shown that a lack of straightness is one of the main reasons for choosing materials other than timber in the construction industry. This paper presents a way to model moisture-induced bow from longitudin...
Article
This paper presents a model that describes the change in magnitude of bow and crook between two moisture contents below the fiber saturation point. The model shows that the variation in the longitudinal shrinkage coefficient over the cross section and along the stud could explain most of the change in bow and crook in the studs. It was possible to...
Article
Full-text available
) trees from one fast-grown and one slow-grown stand in southern Sweden. From the trees 240 studs (45 × 70 × 2500 mm) were taken for measurement of distortion. Wood properties were measured on small specimens (13 × 13 × 200 mm) cut from the studs. Spiral grain angle was found to vary from approximately +3° (left-handed) close to pith to zero 150 mm...
Article
The aim of this study was to find parameters that cause warp. The study comprised 190 studs (45 × 95 × 2500 mm) of Norway spruce (Picea abies) from Sweden. Warp was measured five times in different moisture conditions. A number of parameters were registered on the studs, for example, average distance from the pith, grain angle, amount of juvenile w...
Article
Timber is a natural material that is environmentally friendly, renewable, light, strong and, in the eyes of most people, beautiful. Timber does, however, have one important drawback when it is used in a modern mechanised building process - its lack of straightness. This is one of the main reasons for the building industry to choose materials other...
Article
Full-text available
This paper deals with the development of models for twist in structural timber. Twist was measured on 240 studs of Norway spruce (Picea abies). Several material parameters were also measured, such as spiral grain angle, shrinkage in all three directions, annual ring width and density. Twist in the studs was measured at four different times at diffe...
Article
Full-text available
Picea abies ) trees from one fast-grown and one slow-grown stand in southern Sweden. From the trees 240 studs (45 × 70 × 2500 mm) were taken for measurement of distortion. Wood properties were measured on small specimens (13 × 13 × 200 mm) cut from the studs. Spiral grain angle was found to vary from approximately +3° (left-handed) close to pith to...
Article
Full-text available
Development of twist of Norway spruce boards (Picea abies Karst.) during normal temperature kiln drying was researched. Oriented tangential boards (18 × 80 × 800 mm) were sawed from diametrical radial planks, with known axial shrinking, density, growth dynamics and spiral grain angle (SGA). Unrestrained boards were later on kiln dried at normal tem...
Article
The drying quality is defined from the end-users' (building industry) viewpoint. The most significant problems related to timber quality were identified (Johansson et al. 1994; Kliger et al. 2001) and are 1) to minimise/prevent distortion of timber as a result of drying and in service conditions and 2) to achieve the target moisture content (MC) an...
Article
Full-text available
The potential of utilizing eigenfrequencies corresponding to edgewise bending modes for predicting the bending strength of timber is investigated. The research includes measurements of axial and transversal resonance frequencies, laboratory assessment of density, static bending stiffness and bending strength of 105 boards of Norway spruce of dimens...
Article
Full-text available
Strength grading of Norway spruce side boards in the wet state was investigated. For a batch of 58 boards, densities and dynamic modulus of elasticity in the axial direction, MOE dyn , were determined in the wet state. The boards were then split into two parts and the procedure of determining MOE dyn was repeated both before and after the boards we...
Article
Full-text available
The limiting factor when it comes to design timber structures is often the stiffness properties of timber products. The stiffness requirements in serviceability limit state, both short-term and final deformation especially in horizontal members, is a factor that often makes it necessary to increase the dimensions of the member. This cause increased...

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Projects

Projects (3)
Project
The project's goal is to quantify the structural damping in as-built tall timber buildings (TTB), identify and quantify the effects of connections and non-structural elements on the stiffness, damping and wind-induced dynamic response of TTBs, develop a bottom-up numerical finite element model for estimating the dynamic response of multi-storey timber buildings, validate the predicted response with in-situ measurements on TTBs and disseminate findings via a TTB Design Guideline for design practitioners. The project is supported under the umbrella of ERA-NET Cofund ForestValue. Project coordinator: RISE Research Institute of Sweden Project partners: - NTNU Norwegian University of Science and Technology (Norway) - University of Exeter (UK) - University of Ljubljana (Slovenia) - InnoRenew CoE (Slovenia) - CSTB Centre Scientifique et Technique du Bâtiment (France) - Linnaeus University (Sweden) - Moelven Töreboda AB (Sweden) - Moelven Limtre AS (Norway) - SWECO Norge AS avd Lillehammer (Norway) - Smith and Wallwork Engineers Ltd (UK) - GALEO (France) - EIFFAGE (France) - ARBONIS (France)
Project
The aim of the present project is to develop a prediction tool for laminated veneer products (LVPs) to make it possible for the industry to improve product performance by reducing rejects and customer complaints and reducing time from idea to market by means of a tool to simulate LVP performance.
Project
The aim of the project is to develop self-centred connections ready to be tested for assembly of different types of wood elements such as CLT, glulam, LVL and structural timber.