Directional properties wood is an orthotropic and anisotropic material. Wood has been used by humans for thousands of years as tools, fuel, weapons, structures and for recreation. Wood is a complex polymeric cellular material with complex structure due to its growth. Mechanical properties of wood structure characteristics of 35year old homegarden teak from wet and dry localities of kerala, india in comparison with plantation teak j indian academy of wood. Emphasis is given to courses that provide a fundamental education in the properties of wood, manufacturing processes for wood based materials. Module 8 wood utilization and technology preface an educational priority of the nova scotia department of natural resources is to help landowners manage their woodlots. The experiment was laid out in complete block design cbd. Resource information the item science and technology of wood. Pdf wood is a renewable natural resource which can effectively reduce climate change. This describes features and functions of whole trees, then discusses the structure of wood and finally explains the microscopic and chemical structure of cell walls. Their function is to transport fluids, andor for strengthening parenchyma. Beside others, structural properties and biological durability determine the limits for the use of wood. If the inline pdf is not rendering correctly, you can download the pdf file.
This module is the eighth in a series of woodlot management home study courses designed to meet this goal. The most important properties of wood, therefore, are youngs modulus stiffness and yield strength or compressive strength. Without oxygen and moisture, few microorganisms can survive, and, wood that is free of inorganic salts and other contaminates can also survive with little change. Publication date 1949 topics technology, engineering.
The set of wood cells at right is being squished by a force from above across the grain. This guide uses nominal member size, but it is important to note that the designer must apply the. Historical wood structure and properties sciencedirect. Woods fuel value cant change by preserving but its teak value can change by increasing the life of wood. Additional information on wood properties and characteristics is given in references listed at the end of this chapter. These terms date from the medieval timber trade and were originally meant to give an indication of the hardness of the wood. Thus, the smallest practical size timber is a 6x6 inch. Introduction to wood structure and characteristics terry conners, forestry for123 knowing how to identify unknown pieces of wood using a hand lens is the only skill you will need for most situationsand thats the purpose behind most of this manual. Tsoumis is a fulbright scholar and a fellow of the international academy of wood science. Trees are living organisms with a great variability in structure and properties. The effects that variations in these properties have on the strength of wood are more fully discussed in section iv.
Verlag kessel reprint of the edition from 1991 with permission of dr. Wood preservation is the art of preserving timber against the. Attempting to understand wood in the context of wood technology, we have often overlooked. George tsoumis science and technology of wood structure, properties, utilization. Part 1 contains chapters that deal with the structure of wood at the gross, cellular and molecular levels. The macroscopic structure of wood is shown on the right. George tsoumis science and technology of wood structure. Mechanical and physical properties of semiisostatically. Figure 3 densified spruce image size 1200900 mm2, manual. Apr 20, 2018 a multiomics quantitative integrative analysis of lignin biosynthesis can advance the strategic engineering of wood for timber, pulp, and biofuels. In this study some of the important properties of experimentally manufactured woodplastic composites wpc were determined. Part since the sixth edition of this textreference was published in 1981, there have been developments in the field of timber that this seventh edition represents an almost total. Structure, properties, utilization, and appendices which include a discussion of secondary products, the identification of european, north american and tropical woods including macroscopic keys and brief details of geographical source, properties and uses, and a discussion on bark including cork structure, properties and utilization.
Some of the major advantages of wpc include their resistance against biological deterioration for outdoor applications where untreated timber products. Physical and mechanical properties of juvenile wood from scielo. Some basic properties of timber such as physical and mechanical were determined from. Introduction to wood utilization and technology the forest is one of the most valuable resources in nova scotia. A structure does not care which design method was used behavior is independent of design rules asd has worked fine for. He holds a degree in forestry from the aristotelian university, a masters degree in wood technology from the university of michigan and a doctor of forestry degree from yale university. There are actually hundreds of different species of trees, so making generalizations about something called wood isnt always that helpful. A section at the end about how to identify wood using a microscope is available should you. Emphasis is given to courses that provide a fundamental education in the properties of wood, manufacturing processes for woodbased materials. The wood structural engineering option provides the student with knowledge in the analysis and design of wood structures. Horizontal elements vertical elements resultant inertial forces g r o u n d m o t io n slide emphasizes that basic design principles apply to wood structures. Unlike tracheids, wood parenchyma normally live for many years.
Physical and mechanical properties of selected wood species in tropical rainforest ecosystem, ondo state, nigeria jamala, g. Wood properties, damage and preservation kk510 wood utilization and engineered wood products kk520 human health and hygiene general vv000 animal and invitro models for pharmaceuticals. Structure and function of wood alex wiedenhoeft, botanist 31 wood is a complex biological structure, a composite of many chemistries and cell types acting together to serve the needs of a living plant. Part 2 has five chapters on the properties of wood, with special coverage of elastic behaviour, toughness and the use of structuralsized timber for strength tests.
Commercial timbers fall into two categories softwoods and hardwoods. Structure and properties materials science foundations. Thus, wood preservation helps in the proper utilization of wood and in the conservation of wood resources and forests 3. The design properties given in the nds supplement are based on two different sets of. Due to its organic celltype structure, the density of wood remains modest. Center for wood anatomy research large database for species information, wood. These terms date from the medieval timber trade and were originally meant to give an indication of. Wood an introduction to its structure, properties, and uses. This option provides the student with background in wood and woodbased materials, codified design procedures, design and detailing of wood structures, statistical methods, and basic structural analysis. Wood and furniture design and technology, wood technology lab, 43100, karditsa, greece. Summarizes information on wood as an engineering material.
Wood science and technology west virginia university. Moisture content wood properties and dimensions change with moisture content mc. Structure and properties of wood canadian wood council. The gross structure of wood macrostructure the relationship between the technical properties of wood and its anatomy cell types and characteristics softwood microstructure hardwood microstructure reaction wood. A regional center for development of the wood products industry, the appalachian hardwood center, is allied with the wood science and technology program.
Structure and properties of woodbased materials 8 cpu, 5. Wood properties growth and structure the aim of this is to describe how wood grows in the tree and what wood consists of. Wood technology in the design of structures hoyle, robert j. Module 8 wood utilization and technology nova scotia. Improving wood properties for wood utilization through. Woodplastic composites wpc are widely used in usa, the most common type of such panels are produced by mixing wood flour and plastics to produce a material that can be processed similar to 100% plasticbased products. Physical and mechanical properties of selected wood species. The effect of structure, moisture and temperature on properties. Properties of wood the wood consists of rows of tube. Living wood contains a considerable amount of free and bound water. The inner structure of a tree makes wood what it iswhat it looks like, how it behaves, and what we can use it for. Wood structure school of materials science and engineering. The bark consists of the deceased outer section and the living inner section.
Improving wood properties for wood utilization through multi. Its structure, properties and utilization by desch, h. Fpl publications a large list of fpl publications related to wood properties, processing and use. Lateral the basic approach to the lateral design of wood structures is the same as for other structures. Such uses are in considerable part determined by the properties of lignin in wood. Part 1 is a discussion of wood structure, dealing with macroscopic, physical and microscopic characteristics, chemical composition and ultrastructure, the mechanism of wood formation by trees, variation of structure, and abnormalities in wood.
Introduction to wood properties and wood products puu25. This directional dependence of wood structural properties again reflects its. Aaas project 2061 science for all americans materials science and technology is a multidisciplinary approach to science that involves designing, choosing, and using three major classes of materialsmetals, ceramics, and polymers plastics. Wood structure and its physical properties course no. The centers staff frequently provides opportunities for educational and professional development of wood science and technology students. A revised version of a book originally published in greek in 1983. Presents properties of wood and wood based products of particular concern to the architect and engineer.
A good understanding of the structure of wood, and its properties, is helpful to achieve wise use. He is the author of wood as raw material, as well as the section on wood and wood products in the encyclopedia britannica. Thus, as its strength and stiffness can in certain cases attain remarkable values, its levels of specific strength and stiffness absolute strength or stiffness divided by density can reach magnitudes which are competitive with those of other construction materials. Science and technology of wood structure, properties. Specimen having 60% and 80% particle and fiber of radiata pine pinus radiata were mixed with polypropylene plastic and four different additives, namely structor tr 016 which is coupling agent, ciba antimicrobial agent irgaguard f3510 as fungicide, ciba uv filter.
Physical and mechanical properties of selected wood. The minor in wood science and technology is designed to provide students with specialized knowledge and skills in the properties, manufacture, and utilization of wood and related biomaterial products. Science and technology of wood structure, properties, utilization. Department of forestry and wood technology, federal university of technology akure, ondo state, nigeria.
The display consists of sections of rubber honeycombs that simulate the microstructure of wood. Wood which comes from the forest may be regarded as the final stage in the development of a living tree. Bark, wood, branches, and cambium a cross section of a tree fig. Includes discussion of designing with wood and wood based products along with some pertinent uses. Wood has long been used as construction material and for pulp and paper production. Some of the properties of woodplastic composites sciencedirect. Wood properties, damage and preservation kk510 wood utilization and engineered wood products kk520 human health and hygiene general vv000 animal and invitro models for pharmaceuticals vv450. Structural and other properties of modified wood waldemar homan1, boke tjeerdsma1, erwin beckers1 and andre jorissen2 abstract wood is not under all circumstances an appropriate building material. Three appendices discuss secondary forest products, identification keys for temperate and tropical woods, and use of. The opportunity has been taken to rearrange the structure and broaden the scope to cover areas of conversion, machining and the application of paints and finishes. Madison, wi, usa e informationsdienst holz home of the holzbau handbuch, a series of publications on wood construction in germany. Wood chemical composition hemicellulose a celluloselike material in the wood cell wall that is easily decomposed by dilute acid to yield simple sugars extractives organic material deposited during heartwood formation gums, resins, oils, alkaloids. The earlywood cells are usually broader because they carry more water in the spring for the leaves and new shoots. Wood that has been kept dry over centuries survives with little change in structure or properties.
Toughness is also important but to a lesser degree. This chapter briefly describes some elements of wood structure. The physical properties of wood most relevant to structural design and performance are discussed in this section. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. Structure, properties, utilization, and appendices which include a discussion of secondary products, the identification of european, north american and tropical woods including macroscopic keys and brief details of geographical source, properties and uses, and a discussion on bark including cork. Its utilization is the base of many industries in the province. The aim of this paper is to present a basic understanding of wood structure and chemistry and to relate this to a better understanding of changes in structure and chemistry that occur in historic and archaeological wood. A1 and abraham, p1 1adamawa state college of agriculture, dept.