[PDF] Effect Of Moisture On Fracture Toughness Of Composite Wood Bonded Interfaces eBook

Author : BS. Trimble
Publisher :
Page : 19 pages
File Size : 36,75 MB
Release : 2000
Category : Bonded interface
ISBN :

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Current research on wood reinforcement has focused on the use of fiber-reinforced plastic (FRP) strips or fabrics bonded to wood members. Although significant increases in stiffness and strength have been achieved by this reinforcing technique, there is a concern about the reliable performance of the wood-FRP interface bond, which can be susceptible to delamination. The objective of this study is to present a combined analytical/experimental study to evaluate the effect of moisture on fracture toughness of composite/wood bonded interfaces under Mode I loading. A contoured double cantilever beam (CDCB) specimen is used to characterize the fracture toughness of both wood-wood and wood-FRP samples. The specimens are designed by the Rayleigh Ritz method to achieve a linear rate of compliance with respect to crack length and are calibrated experimentally and also analytically by the finite element method. Both wood-wood and wood-FRP samples are tested under dry and wet conditions, and bonded interface fracture toughness data under Mode I loading are obtained. The guidelines and procedures for the modeling and design of CDCB specimens for hybrid or dissimilar adherends using a Rayleigh-Ritz model are presented briefly, and a modified Rayleigh-Ritz method is further developed. The effect of moisture on fracture toughness is evaluated, and increases in interface fracture toughness are observed due to moisture absorption for wet wood-wood and wood-FRP samples; the toughening of the interface under moisture is due mainly to a much more plastic fracture failure mode of the interface.

Author : P.J.M. Monteiro
Publisher : Elsevier
Page : 313 pages
File Size : 10,29 MB
Release : 2001-08-29
Category : Technology & Engineering
ISBN : 0080535593

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"Long Term Durability of Structural Materials" features proceedings of the workshop held at Berkeley, CA in October, 2000. It brought together engineers and scientists, who have received grants from the initiative NSF 98-42, to share their results on the study of long-term durability of materials and structures. The major objective was to develop new methods for accelerated short-term laboratory or in-situ tests which allow accurate, reliable, predictions of the long-term performance of materials, machines and structures. To achieve this goal it was important to understand the fundamental nature of the deterioration and damage processes in materials and to develop innovative ways to model the behavior of these processes as they affect the life and long-term performance of components, machines and structures. The researchers discussed their approach to include size effects in scaling up from laboratory specimens to actual structures. Accelerated testing and durability modeling techniques developed were validated by comparing their results with performance under actual operating conditions. The main mechanism of the deterioration discussed included environmental effects and/or exposure to loads, speeds and other operating conditions that are not fully anticipated in the original design. A broad range of deterioration damage, such as fatigue, overload, ultraviolet damage, corrosion, and wear was presented. A broad range of materials of interest was also discussed, including the full spectrum of construction materials, metals, ceramics, polymers, composites, and coatings. Emphasis was placed on scale-dependence and history of fabrication on resulting mechanical behavior of materials.

Author : JF. Davalos
Publisher :
Page : 9 pages
File Size : 34,35 MB
Release : 2006
Category : Composite materials
ISBN :

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The evaluation of durability and shear strength of FRP-wood bonded interfaces is presented in Part 1 of this two-part study (see Davalos et al. [1]); here, in Part 2, an innovative contoured double-cantilever beam (CDCB) specimen is used to evaluate Mode I fracture of bonded interfaces, and interface fracture toughness data are experimentally obtained for dry and wet conditions. The specimens are designed by the Rayleigh-Ritz method to achieve a linear rate of compliance with respect to crack length. The proposed CDCB specimen is an efficient tool to evaluate Mode I fracture of hybrid interfaces, and the fracture toughness data obtained can be used to predict whether or not a bonded interface will delaminate under general service conditions. Based on the results of this two-part study, recommendations and guidelines are given for evaluation and qualification of FRP-wood bonded interfaces; the methods presented are useful for designing bonded joints, evaluating in-service durability of interfaces, and obtaining fracture toughness data for FRP-wood material combinations.

Author : Technomic
Publisher : CRC Press
Page : 839 pages
File Size : 16,68 MB
Release : 2022-01-26
Category : Technology & Engineering
ISBN : 1000125289

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This book discusses how the excess value, of the products using braid, is captured in prosthetic limbs, aircraft and automotive components, commercial furniture, and trenchless sewer repair structures. It outlines the braided pultrusion process and also discusses impregnation states.

Author : Golam M. Newaz
Publisher : CRC Press
Page : 1068 pages
File Size : 29,4 MB
Release : 2019-11-28
Category : Technology & Engineering
ISBN : 1000725502

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First published in 1998. A collection of papers presented at the Proceedings of the Eighth Japan-U.S. Conference On Composite Materials, SEPTEMBER 24 to 25 , 1998. The conference is organized by Wayne State University and American Society for Composites in cooperation with U.S. Organizing Committee and the Japanese Organizing Committee. Since the Seventh Meeting in Kyoto in 1995, this meeting brings together accomplished composite researchers between the two countries to share latest developments and advances in the field. The scope of the current conference ranges over all aspects of composite materials with some emphasis on infrastructure applications of composites. Key areas in composites are covered by 110 papers with 35 presentations from Japan.

Author : Voichita Bucur
Publisher : Springer Science & Business Media
Page : 404 pages
File Size : 15,27 MB
Release : 2010-11-02
Category : Nature
ISBN : 9048195500

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In the last quarter century, delamination has come to mean more than just a failure in adhesion between layers of bonded composite plies that might affect their load-bearing capacity. Ever-increasing computer power has meant that we can now detect and analyze delamination between, for example, cell walls in solid wood. This fast-moving and critically important field of study is covered in a book that provides everyone from manufacturers to research scientists the state of the art in wood delamination studies. Divided into three sections, the book first details the general aspects of the subject, from basic information including terminology, to the theoretical basis for the evaluation of delamination. A settled terminology in this subject area is a first key goal of the book, as the terms which describe delamination in wood and wood-based composites are numerous and often confusing. The second section examines different and highly specialized methods for delamination detection such as confocal laser scanning microscopy, light microscopy, scanning electron microscopy and ultrasonics. Ways in which NDE (non-destructive evaluation) can be employed to detect and locate defects are also covered. The book’s final section focuses on the practical aspects of this defect in a wide range of wood products covering the spectrum from trees, logs, laminated panels and glued laminated timbers to parquet floors. Intended as a primary reference, this book covers everything from the microscopic, anatomical level of delamination within solid wood sections to an examination of the interface of wood and its surface coatings. It provides readers with the perspective of industry as well as laboratory and is thus a highly practical sourcebook for wood engineers working in manufacturing as well as a comprehensively referenced text for materials scientists wrestling with the theory underlying the subject.