| 1. |
- Bader, Thomas K., 1980-, et al.
(författare)
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Modeling the Mechanical Behavior of Wood Materials and Timber Structures
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer. - 9783030813147 - 9783030813154 ; , s. 507-568
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Bokkapitel (refereegranskat)abstract
- This chapter aims at highlighting the benefit of numerical methods and their broad application in the field of wood, engineered wood-based products (EWPs), structural elements including glued-laminated and cross-laminated timber, and engineered timber structures. It focuses on the hygrothermo- viscoelastic material behavior of these elements and structures as a consequence of the behavior of wood materials. After motivating the need for models of wood, different types of numerical models and their application for determination of mechanical properties and dimensional stability of wooden boards, strand- and veneer-based engineered woodbased products, including glued-laminated and crosslaminated timber, as well as of connections in EWPs are reviewed and application examples are given. Methods and application examples are furthermore provided for moisturerelated stresses and deformations in timber structures, the influence of connections on the structural response, instability of structural systems, and modeling of prefabricated frame structures, before modeling of historical structures of wood is discussed. The chapter ends with discussing bottlenecks in modeling of wood materials and timber structures, which might be a starting point for further improvements and novel modeling strategies. © Springer Nature Switzerland AG 2023.
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| 2. |
- Niemz, Peter, et al.
(författare)
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Important Data
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1977-2003
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Bokkapitel (refereegranskat)abstract
- This chapter is an Appendix that provides information on material and process parameters. The data may constitute a basis for a first approximation in calculations of material characteristics and production capacities, etc. The presentation is in tabular form, sometimes with indications of the variation range. Data are presented for solid wood of different species and from different parts of the world, modified wood, and wood-based materials. Information on natural fibers, adhesives, and coating materials is also provided. For some selected processes, values for material and energy consumption during the production of materials such as sawn timber, wood-based materials, paper pulp, and paper are also presented. The chapter also contains an overview of standardization in different regions of the world, and a compilation of useful books in the field of wood science and technology.
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| 3. |
- Sandberg, Dick, et al.
(författare)
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Advanced Engineered Wood-Material Concepts
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1835-1888
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Bokkapitel (refereegranskat)abstract
- The variety of wood-based products is huge; some are produced and marketed in large volumes while others are for a very specific use and therefore also often only produced in small volumes. This chapter introduces a group of new materials, existing mainly only in laboratories or in production at pilot scale. These materials often go under the name bioinspired materials and smart wood-based materials. The second part of the chapter presents engineered wood products (EWPs) with other or additional functions than only the load-bearing capacity related not only to properties such as acoustic, heat transfer, light-weight, and extraordinary shape stability, but also to functions such as hybrid functions, improved possibility to form to a given shape, installation solutions, and esthetic and tactile performance. These materials are already on the market since many years and are in this chapter briefly introduced.
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| 4. |
- Sandberg, Dick, et al.
(författare)
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Forming, Densification and Molding
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 943-989
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Bokkapitel (refereegranskat)abstract
- An important principle in product design is the Form follows Function principle. The forming processes are basically divided into cutting and chipless manufacturing processes. Chipless forming has the advantage of manufacturing parts without any interruption or damage to the natural fiber orientation in the wood, so that parts can be made considering the force progression. In this chapter, forming, densification, and molding deal with different forming technologies of wood. The description of the wood-bending process focuses on historical technologies. Basic considerations are discussed in the two-dimensional bending and three-dimensional forming of veneer. The densification of wood, which is a more recent technology, is also explained in this chapter, and the molding of wood-plastic composites, especially in extrusion and injection molding processes, and shaping by additive (generative) processes are also considered.
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| 5. |
- Sandberg, Dick, et al.
(författare)
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Process Control and Grading in Primary Wood Processing
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1019-1073
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Bokkapitel (refereegranskat)abstract
- Round timber and wood products are measured, sorted, and graded at different stages in the wood-value chain starting already at the stem level in the forest. This chapter gives an overview of grading methodologies and techniques for the measurement and grading of round timber, sawn timber, veneer, and wood-panel products. The section concerning round timber focuses on the grading and sorting of logs for sawmill and veneer production. For sawn timber, visual and strength grading are discussed, for both the European and the North American markets. Techniques for measurement and process control in the wood-panel industry are finally discussed, where the different industrial methods used today are in focus rather than the specific grading rules used in the industry. The technologies presented have a broader application outside the field of the wood-panel industry, and can be of interest for the measurement of wood composites in general.
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| 6. |
- Sandberg, Dick, et al.
(författare)
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Sawmilling
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1097-1166
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Bokkapitel (refereegranskat)abstract
- Sawmilling is the conversion of round timber of a defined geometry and quality into sawn timber in accordance with given or custom-ordered specifications regarding dimensions and quality. This process also results in by-products such as bark, sawdust, and chips. An industrial sawmill operation is a complex process involving external and internal logistics, optimization, and process control in order to maximize the value yield and to reduce operating costs. The volume yield of sawn timber is of great importance. Sawmills are classified according to their main machining concept such as frame-saw mills, bandsaw mills, circular-saw mills, profiling-technology-based mills, etc. In this chapter, various sawmill concepts and machining technologies are described and the basic approaches to achieve optimization are introduced. The sawing machines are described on a conceptual basis and sawmill design, selection, and maintenance are surveyed.
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| 7. |
- Teischinger, Alfred, et al.
(författare)
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Glossary of Wood Science and Technology Terms
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 2005-2026
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Bokkapitel (refereegranskat)
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| 8. |
- Teischinger, Alfred, et al.
(författare)
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Introduction to Wood Industries
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1077-1095
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Bokkapitel (refereegranskat)abstract
- This chapter provides a general definition of the term “industrial production” and lists the main industrial sectors. A short history of the emergence and development of industrial production is given, culminating in the development of smart production. The emergence of different single technologies and processes within the forest-based industrial sector is briefly surveyed, and the different industrial branches are structured and introduced with specific key data. The forest-based industrial sector consists of different interconnected process chains to create a resource-efficient production system. These process chains are highlighted and a short analysis and introduction to each of these process chains is provided.
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| 9. |
- Teischinger, Alfred, et al.
(författare)
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Sawn-Timber Products
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 9783030813147 - 9783030813154 ; , s. 1283-1346
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Bokkapitel (refereegranskat)abstract
- Sawn-timber products are products processed from sawn timber, where the appearance and the other properties of the final product are strongly related to the sawn timber. This chapter begins with sawn timber in general and presents the various sawn timber products such as solid timber for construction, glued-laminated timber (glulam), cross-laminated timber (CLT), and solid-wood panels in detail. Further timber-based products comprising pattern, millwork, cabinetry, pallets, trusses, etc., are highlighted shorty. The various product-specific technologies, manufacturing processes, as well as product properties and applications are described. Some key market data are provided to each of the product category. The chapter ends with a short survey of joinery-machining concepts for customizing the sawn-timber products.
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| 10. |
- Thybring, Emil Engelund, et al.
(författare)
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Wood and Moisture
- 2023
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Ingår i: Springer Handbook of Wood Science and Technology. - 9783030813154 - 9783030813147 ; , s. 355-397
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Bokkapitel (refereegranskat)abstract
- Wood is a porous, hygroscopic material that can take up water both within cell walls (cell-wall water) and in the macrovoid structure (capillary water). Therefore, moisture transport in wood occurs through multiple pathways and phases of water, that is, both cell-wall water, liquid water, and water vapor can be transported through the material structure. The amount of water in wood is quantified by the moisture content (mass of water in relation to the dry mass), which changes with the surrounding environmental conditions (relative humidity and temperature). This relation is commonly depicted in sorption isotherms that plot the equilibrium moisture content as function of relative humidity for specific, constant temperatures. How water is taken up by wood changes over the relative humidity range. In the hygroscopic range (0% to 97–98% relative humidity), water is predominantly taken up in cell walls, whereas capillary condensation of liquid water in the macrovoid structure becomes dominant in the over-hygroscopic range (>98% relative humidity). The equilibrium illustrated in sorption isotherms for specific environmental conditions is not singular, but depends on the sorption history; this phenomenon is known as sorption hysteresis. Sorption isotherms are generally modeled using mathematical expressions that are fitted to data in the hygroscopic range. Some of these models include quantities describing the physical reality of wood-water interactions; however, these quantities rarely match up to the experimentally determined reality for wood. The same can be said of the mathematical models describing the kinetics of water uptake in wood cell walls.One of the most well-known concepts concerning water in wood is the fiber saturation point (FSP). It can be found as the threshold moisture content above which physical wood properties do not change significantly with moisture content. The FSP is, however, lower than the maximum moisture content of wood cell walls which occurs in the fully water saturated state. A change in moisture content below the FSP is accompanied by dimensional changes, that is, shrinkage and swelling, which reflect changes in the amount of water within cell walls. While this phenomenon originates at the nanoscale, it is observed on all length scales of wood. Such dimensional changes as well as other physical wood properties and fundamental wood-water interactions can be altered by chemical modification of wood. How these relations are affected depends on the chemical nature of the modification. At the end of this chapter, a broad overview is given of experimental methods for characterizing moisture in wood, including determination of moisture content, sorption isotherms, moisture state and location, and moisture transport in wood.
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