[PDF] Wood Fracture Characterization eBook

Author : Marcelo F. S. F. de Moura
Publisher : CRC Press
Page : 137 pages
File Size : 11,62 MB
Release : 2018-06-14
Category : Science
ISBN : 1351106961

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Wood Fracture Characterization provides a guide to the application of modern fracture mechanics concepts to wood materials used in structural engineering, which commonly involve discontinuities and irregularities. The authors cover the tests, data reduction schemes and numerical methods devised for wood structural applications, based on cohesive zone analysis, and used to validate experimental-based methodologies. Five detailed Case Studies are included to link theory with engineering practice. This important new text explains the basics of fracture mechanics, and extends them as needed to cover the special behaviour of an anisotropic wood materials.

Author : Martin Rhême
Publisher : LAP Lambert Academic Publishing
Page : 152 pages
File Size : 26,84 MB
Release : 2015-02-02
Category :
ISBN : 9783659669873

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Wood is a naturally growing material used from ages, but the applications for a single wood piece are limited by the shape and girth of the tree from where the piece is derived. Assembling wood pieces together enables working around this issue. Development in the last 10 years have highlighted the possibility to weld wood instead of the more classical mechanical fastener or polymeric adhesive already known as bonding techniques. While offering high processing speed and ecological advantages, past research have reported poor water resistance of the welded joint. Furthermore, high scatter of the mechanical properties and a lack of quantitative dependence with moisture content prevent performing accurate prediction regarding the joint failure. The aim of this work is to investigate the fracture behavior of the welded joint in a range of moisture content below the fibre saturation point. Combined experimental and numerical work are use to characterize the effects of moisture content and mixed mode loadings and a finite element model is suggested to predict crack propagation in the welded joint.

Author : Ian Smith
Publisher : John Wiley & Sons
Page : 248 pages
File Size : 29,59 MB
Release : 2003-06-02
Category : Technology & Engineering
ISBN : 9780471487081

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Damage in wood is principally the result of fatigue. Fatigue is the process of progressive localised irreversible change in a material, and may culminate in cracks or complete fracture if conditions that initiated or propagated the process persist. Comprehensive understanding of fatigue and fracture in engineered wood components must be founded on a proper understanding of the damage processes. Although wood is the world's most widely used structural material, whether measured by volume consumed or value of finished construction, its behaviour is not well understood even by people who have spent their careers studying it. * What is known about failure processes comes almost entirely from empirical evidence collected for engineering purposes. * Hypotheses about behaviour of wood are based on macroscopic observation of specimens during and following tests. * With only limited resources and the need to obtain practical results quickly, the timber engineering research community has steered away from the scientific approach. * Forestry practices are changing and are known to influence characteristics of wood cells therefore there is a need to periodically reassess the mechanical properties of visually graded lumber the blackbox approach. Fatigue and Fracture of Wood examines the above issues from a scientific point of view by drawing on the authors' own research as well as previously published material. Unlike the empirical research, the book begins by examining growth of wood. It briefly examines its structure in relation to how trees grow, before assessing the fatigue and fracture of wood and discussing the scientific methods of modelling fatigue. * Covers from macro to micro behaviour of wood * Presents direct evidence of how wood fractures using Scanning Electron Microscopy * The first book to present a physically correct model for fracture in wood * Provides experimental proof of so-called memory in wood (i.e. dependence of fatigue behaviour on the loading sequence) * Givse practical illustrations of how theories and models can be applied in practice An essential resource for wood scientists/engineers, timber-engineering practitioners, and graduate students studying wood and solid mechanics.

Author : Shehab Sherif Wissa Agaiby
Publisher :
Page : 251 pages
File Size : 29,60 MB
Release : 2013
Category :
ISBN :

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Fracture mechanics has been used for many years to study the mechanical behavior of brittle and quasi-brittle materials like concrete, rock, wood, and ceramics. To date, the application of fracture mechanics to soils has been limited to dry and partially saturated soils where soil consistency changes due to suction and tends to be harder exhibiting a quasi-brittle behavior. Of late, studying fracture propagation in clays and mudrocks has become of interest as it provides a means to extract oil from oil bearing strata. While crack initiation in soils can be analyzed using basic soil mechanics theories, development and propagation of a crack is energy driven and requires application of fracture mechanics principles. An essential parameter in Linear Elastic Fracture Mechanics (LEFM), the main analytical tool in studying fracture in rock, is the critical stress intensity factor that defines stress concentration near a crack tip beyond which a fracture would propagate. The basic mode of crack loading can be obtained by applying a normal stress that has a corresponding opening mode of crack surface displacement, called mode-I (tensile mode), with a critical stress intensity factor termed fracture toughness, denoted by KIC. In this experimental research, KIC is measured indirectly using a modified Brazilian Test configuration where load is applied normally on flattened Brazilian disk specimens without the need to introduce a flaw into the specimen. Intact natural specimens from four different deposits; Boston Blue clay, San Francisco Bay Mud, Presumpscot Maine clay, and Gulf of Mexico clay; are tested in oven-dried state under atmospheric conditions. In addition, two Clay-like materials; molded Gypsum and Plaster of Paris; have been investigated. Based on the analysis of the test data, the relation between mode I fracture toughness and tensile strength for the six tested materials agrees to a great extent with reported trends in the literature even for different fracture toughness and tensile strength testing techniques and for wider tested range of soils, rocks, geomaterials, clay-like, and rock-like materials. However, no clear relation between mode I fracture toughness and elastic modulus or any other physical parameter was determined.

Author : Yohei Endo
Publisher : Springer Nature
Page : 1340 pages
File Size : 14,13 MB
Release : 2023-10-03
Category : Technology & Engineering
ISBN : 303139450X

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This book gathers the peer-reviewed papers presented at the 13th International Conference on Structural Analysis of Historical Constructions (SAHC), held in Kyoto, Japan, on September 12-15, 2023. It highlights the latest advances and innovations in the field of conservation and restoration of historical and heritage structures. The conference topics encompass history of construction and building technology, theory and practice of conservation, inspection methods, non-destructive techniques and laboratory testing, numerical modeling and structural analysis, management of heritage structures and conservation strategies, structural health monitoring, repair and strengthening strategies and techniques, vernacular constructions, seismic analysis and retrofit, vulnerability and risk analysis, resilience of historic areas to climate change and hazard events, durability, and sustainability. As such the book represents an invaluable, up-to-the-minute tool, providing an essential overview of conservation of historical constructions, and offers an important platform to engineers, architects, archeologists, and geophysicists. Chapter The Challenges of the Conservation of Earthen Sites in Seismic Areas, Chapter Performance Evaluation of Patch Repairs on Historic Concrete Structures (PEPS): Preliminary Results from Two English Case Studies are available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

Author : Douglas D. Stokke
Publisher : John Wiley & Sons
Page : 296 pages
File Size : 39,43 MB
Release : 2008-02-28
Category : Science
ISBN : 0470999705

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This volume brings together a broad array of scientific expertise to focus on the characterization and utilization of cellulosic materials. Researchers from Austria, Germany, Sweden, Japan, New Zealand, Australia, and the U.S. explore many facets of the plant cell wall, from its fundamental structure and its manipulation via molecular biology to its application in composite materials. Exciting applications of near infrared spectroscopy, x-ray diffraction, confocal microscopy, and molecular coupling as a viscoelastic probe provide new insights into the ultrastructure and properties of cellulosic materials.