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12 records – page 1 of 2.

Agricultural Buildings With Timber Structure - Preventative Chemical Wood Preservation Inevitably Required?

https://research.thinkwood.com/en/permalink/catalogue1914
Year of Publication
2018
Topic
Moisture
Application
Wood Building Systems
Author
Jiang, Yuan
Dietsch, Philipp
Winter, Stefan
Year of Publication
2018
Format
Conference Paper
Application
Wood Building Systems
Topic
Moisture
Keywords
Moisture Content
Spruce
Agriculture
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 20-23,2018. Seoul, Republic of Korea
Summary
Wood preservation is an important issue for agricultural buildings with timber structure. This is among others due to their halfway opened construction, high level of moisture release from livestock breeding or storing goods. However, regarding the possibly high moisture content in the building structure and the potential threat caused by wood-destroying organisms, there is still a substantial need for research. The latest results of the research work carried out by Technical University of Munich, in cooperation with the Bavarian State Research Center for Agriculture, show that, for the most agricultural buildings built from spruce, no preventative chemical wood preservation is necessary to ensure a durable construction.
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Applicability of Various Wood Species in Glued Laminated Timber - Parameter Study on Delamination Resistance and Shear Strength

https://research.thinkwood.com/en/permalink/catalogue592
Year of Publication
2014
Topic
Mechanical Properties
Connections
Material
Glulam (Glue-Laminated Timber)
Author
Jiang, Yuan
Schaffrath, Jörg
Knorz, Markus
Winter, Stefan
Van de Kuilen, Jan-Willem
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Connections
Keywords
Hardwood
Softwood
Gluability
Delamination
Shear Strength
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
In a current research project the gluability of various soft- und hardwood species and their applicability in glued laminated timber are investigated. The influence of the processing parameters on the delamination resistance and shear strength of the glue lines are presented in this work. The bonding forces, which are necessary for the integrity of a glue line, act in the interface within a distance that varies from nanometers to micrometers. The parameters that may have significant influence on the bonding strength and durability of adhesive joints are numerous and depend on the type of wood, adhesive and processing conditions.
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Cross Laminated Timber (CLT) – Reinforcements with Self-Tapping Screws

https://research.thinkwood.com/en/permalink/catalogue1487
Year of Publication
2010
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)

Design of Shear Reinforcement for Timber Beams

https://research.thinkwood.com/en/permalink/catalogue1109
Year of Publication
2013
Topic
Connections
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Dietsch, Philipp
Kreuzinger, Heinrich
Winter, Stefan
Year of Publication
2013
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Connections
Design and Systems
Keywords
Shear
Reinforcement
Fractured
Unfractured
Conference
CIB-W18 Meeting
Research Status
Complete
Notes
August 26-29, 2013, Vancouver, Canada p.193-209
Summary
The use of glulam beams with changing depth offers the possibility to adapt the section modulus to the bending moment. In the case of single-span beams under uniformly distributed load, however, a change in beam depth will lead to a contrary effect for the shear stresses, see Figure 1. Curved and pitched cambered beams feature not only high utilization rates in bending but also areas of high tension stresses perpendicular to the grain and shear parallel to the grain stresses, two stress components for which timber features only small capacities as well as brittle failure modes. Out of 245 cases of damaged or failed large-span timber structures, evaluated in [1], several failures document the possibility of a shear fracture (full separation) developing in grain direction from the curved part towards the supports, partly followed by a failure of the beam in flexural tension due to a change in stress distribution resulting from the change in section modulus. Reinforcements against tension stresses perpendicular to the grain in form of fully threaded screws or threaded rods can be considered state of the art [2], [3]. With respect to their application as shear reinforcement, not many research results are yet available [4], [5], resulting in a lack of experimentally validated design approaches. Within this paper, approaches to design shear reinforcement for glulam beams in the unfractured and the fractured state are presented, validated and discussed. The moment of failure, i.e. the transition from the unfractured to the fractured state is characterized by dynamic effects. This situation is not covered in this paper. A possible approach is given in [1]. The same applies to the subject of moisture induced stresses, resulting from the reinforcement restricting the free shrinkage or swelling of the glulam beam.
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Effects of Changes in Moisture Content in Reinforced Glulam Beams

https://research.thinkwood.com/en/permalink/catalogue1173
Year of Publication
2014
Topic
Moisture
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Dietsch, Philipp
Kreuzinger, Heinrich
Winter, Stefan
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Moisture
Mechanical Properties
Keywords
Reinforcement
Threaded Rods
Moisture Induced Stresses
Finite Element Method
Moisture Content
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Reinforcement in glulam beams in form of screws or rods can restrict the free shrinkage or swelling of the wood material. The objective of the project presented was to evaluate the influence of such reinforcement on the magnitude of moisture induced stresses. For this purpose, experimental studies were carried out in combination with analytical considerations on the basis of the finite-element method. Taking into account the influence of relaxation processes, the results indicate that a reduction of timber moisture content of 3 - 4 % around threaded rods, positioned perpendicular to the grain, can lead to critical stresses with respect to moisture induced cracks. In addition, a substantial mutual influence of adjacent reinforcing elements has been identified. A reduction of the distance between the reinforcement thus results in a lower tolerable reduction of timber moisture content around the reinforcement.
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Fire Resistance of Primary Beam – Secondary Beam Connections with Full Thread Screws

https://research.thinkwood.com/en/permalink/catalogue1712
Year of Publication
2016
Topic
Fire
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Hofmann, Veronika
Gräfe, Martin
Werther, Norman
Winter, Stefan
Year of Publication
2016
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Fire
Mechanical Properties
Keywords
Fire Resistance
Self-Tapping Screws
Fire Tests
Numerical Simulation
Load-Bearing Capacity
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 4495-4503
Summary
Within the German research project “Fire resistance of primary beam - secondary beam connections in timber structures” solutions for a fire-safe design have been developed. The project concentrated on connections with self-tapping full thread screws and joist hangers. This paper describes the investigations, calculations and experiments on the former type of connections. Herein, a series of loaded fire tests and numerical simulations were conducted with the objective to develop design rules and determine the load-bearing capacity.
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Monitoring Building Climate and Timber Moisture Gradient in Large-Span Timber Structures

https://research.thinkwood.com/en/permalink/catalogue108
Year of Publication
2014
Topic
Serviceability
Moisture
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Gamper, Andreas
Dietsch, Philipp
Winter, Stefan
Editor
Bettina Franke Steffen Franke
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Cracks
Damage
Equilibrium Moisture Content
Internal Climate
Lamellas
Large Span
Long-term
Relative Humidity
Shrinkage
Swelling
Temperature
Conference
COST Workshop – Highly Performing Timber Structures: Reliability, Assessment, Monitoring and Strengthening
Research Status
Complete
Summary
The evaluation of damages in large-span timber structures indicates that the predominantly observed damage pattern is pronounced cracking in the lamellas of glued-laminated timber elements. A significant proportion of these cracks is attributed to the seasonal and use-related variations of the internal climate within large buildings and the associated inhomogeneous shrinkage and swelling processes in the timber elements. To evaluate the significance of these phenomena, long-term measurements of climatic conditions and timber moisture content were taken within large-span timber structures in buildings of typical construction type and use. These measurements were then used to draw conclusions on the magnitude and time necessary for adjustment of the moisture distribution to changing climatic conditions. A comparison of the results for different types of building use confirms the expected large range of possible climatic conditions in buildings with timber structures. Ranges of equilibrium moisture content representative of the type and use of building were obtained. These ranges can be used in design to condition the timber to the right value of moisture content, in this way reducing the crack formation due to moisture variations. The results of this research also support the development of suitable monitoring systems which could be applied in form of early warning systems on the basis of climate measurements. Based on the results obtained, proposals for the practical implementation of the results are given.
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Reinforcement of Round Holes in Glulam Beams Arranged Eccentrically or in Groups

https://research.thinkwood.com/en/permalink/catalogue1627
Year of Publication
2016
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Danzer, Martin
Dietsch, Philipp
Winter, Stefan
Year of Publication
2016
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Holes
Self-Tapping Screws
Load Bearing Capacity
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2804-2812
Summary
Experimental and numerical investigations on round holes in glulam beams are presented. These were conducted in order to extend the field of practical application, to study the structural behaviour of holes arranged eccentrically or in groups and to generate basic results for deriving a design format. Within these investigations the influence of parameters like eccentricity, clear distance between holes or effect of reinforcement by fully threaded selftapping screws was considered. A comparison of estimated load-bearing capacities on the basis of the Weibull theory and test results shows good agreement. Strain gauge measurements in reinforcing elements confirm the validity of the chosen methods.
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Seismic strengthening of existing RC buildings with external cross-laminated timber (CLT) walls hosting an integrated energetic and architectural renovation

https://research.thinkwood.com/en/permalink/catalogue3114
Year of Publication
2022
Topic
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Badini, Lorenzo
Ott, Stephan
Aondio, Patrik
Winter, Stefan
Organization
Technical University of Munich
Publisher
Springer
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Seismic
Keywords
Existing Building
Seismic Retrofit
Target Displacement
Energy Retrofit
Numerical Analyses
Research Status
Complete
Series
Bulletin of Earthquake Engineering
Summary
In this study a timber-based integrated solution is presented to solve at once common issues affecting typical reinforced concrete (RC) existing buildings, such as seismic and energy performances, providing an eco-friendly alternative to steel external bracing systems. Cross-laminated timber (CLT) walls are provided perpendicularly to the external façades as strengthening elements while interposed CLT slabs are foreseen at each floor level to host new architectural units together with a new envelope. While the connections to the foundations and to the existing RC frames are provided respectively with steel brackets and axial-connectors distributed along the height of the building, a post-tensioned connection, between CLT panels (PT-CLT connection), is implemented in the system to guarantee resistance to horizontal actions acting parallel to existing façades with consequent structural independence and architectural freedom. On this regards a first look at the findings of an experimental campaign carried on the Technical University of Munich are presented. A numerical model is developed with finite element software characterizing each type of connector for linear and non-linear analyses. Modal analyses with response spectrum are performed to verify structural elements and connectors, while pushover analyses with target displacement checks are performed to assess the obtained seismic improvement. Finally, the preassembled architectural components that allow to renovate the envelope and the provided assembly procedure are revealed.
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Shear Properties of Cross Laminated Timber (CLT) under In-Plane Load: Test Configuration and Experimental Study

https://research.thinkwood.com/en/permalink/catalogue180
Year of Publication
2015
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Brandner, Reinhard
Dietsch, Philipp
Dröscher, Julia
Schulte-Wrede, Michael
Kreuzinger, Heinrich
Sieder, Mike
Schickhofer, Gerhard
Winter, Stefan
Organization
International Network on Timber Engineering Research (INTER)
Year of Publication
2015
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Diaphragms
Failure Mechanisms
Shear Strength
In-Plane Shear Test
Conference
INTER 2015
Research Status
Complete
Notes
August 24-27, 2015, Sibenik, Croatia
Summary
Consolidated knowledge of CLT properties under in-plane shear is crucial for typical structural applications such as wall and floor diaphragms, cantilevered CLT walls and CLT used as (deep) beams, in all cases potentially featuring holes or notches. The current technical approvals for CLT products contain differing regulations to determine their load-carrying capacities in-plane. Generally they imply a verification of the torsional stresses in the cross-section of the cross-wise glued elements as well as a verification of the shear stresses proportionally assigned to the boards of the top and cross layers. The basis of theoretical and practical considerations are the following three basic failure scenarios for a CLT-element under in-plane shear: (i) gross-shear (longitudinal shearing in all layers), (ii) net-shear (transverse shearing in all layers in weak direction), and (iii) torsion failure in the gluing interfaces between the layers
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12 records – page 1 of 2.