A method to predict failure of adhesive joints is described. The fracture criterion is based on material-induced singularities that appear at the terminus of the joint. The criterion can be interpreted physically in terms of the elastic strain energy density. The criterion is formulated in terms of a singular intensity factor Q that is analogous to the stress intensity factor for the case when cracks are present. The strengths of the singularities are dependent on the elastic properties of the adhesive and the adherends and on the geometry of the bond terminus, but are postulated to be independent of loading and global geometry.

The Mechanics of Adhesion shows that adhesion science and technology is inherently an interdisciplinary field, requiring fundamental understanding of mechanics, surfaces, and materials. This volume comprises 19 chapters. Starting with a background and introduction to stress transfer principles; fracture mechanics and singularities; and an energy approach to debonding, the volume continues with analysis of structural lap and butt joint configurations. It then continues with discussions of test methods for strength and constitutive properties; fracture; peel; coatings, the case of adhesion to a single substrate; elastomeric adhesives such as sealants. The role of mechanics in determining the locus of failure in bonded joints is discussed, followed by a chapter on rheology relevant to adhesives and sealants. Pressure sensitive adhesive performance; the principles of tack and tack measurements; and contact mechanics relevant to wetting and surface energy measurements are then covered. The volume concludes with sections on fibermatrix bonding and reinforcement; durability considerations for adhesive bonds; ultrasonic non-destructive evaluation of adhesive bonds; and design of adhesive bonds from a strength perspective. This book will be of interest to practitioners in the fields of engineering and to those with an interest in adhesion science.

Adhesively-bonded joints provide many advantages over conventional mechanical fasteners and are increasingly receiving attention as an alternative to mechanical joints in engineering applications. The traditional fasteners usually result in the cutting of fibers and hence the introduction of stress concentrations, both of which reduce structural integrity. By contrast, bonded joints are more continuous and have potential advantages of strength-to-weight ratio, design flexibility, and ease of fabrication. This book provides an overview of available analytical methods as well as numerical methods.

This volume documents the proceedings of the International Symposium on Adhesive Joints: Formation, Characteristics and Testing held under the auspices of the Division of Polymer Mater ials:Science and Engineering of the American Chemical Society in Kansas City, MO, September 12-17, 1982. There is a myriad of applications (ranging from aerospace to surgery) where adhesives are used to join different materials, and concomitantly the understanding of the behavior of adhesive joints becomes very important. There are many factors which can influence the behavior of adhesive joints, e.g., substrate preparation, in terfacial aspects, joint design, mode of stress, external environ ment, etc., and in order to understand the joint behavior in a holistic manner, one must take due cognizance of all these germane factors. So this symposium was planned to address not only how to make acceptable bonds but their characterization, durability and testing were also accorded due consideration.

Although adhesively bonded lap joint has already been widely applied in structures, the strength prediction of the joint is still a challenge. Among many parameters which affect the failure load of the lap joint, the adhesive layer thickness is a very important one. In this book, fracture mechanics is used to analyze the failure mechanism of the lap joint and evaluate the thickness effect on strength of the lap joint. For brittle material, constant effective fracture toughness is proposed for better strength prediction by considering of the non- singular stress term ahead of the crack tip. For ductile material, CTOA is proven to be insensitive to the constraining of the rigid boundaries and can be used as the failure criterion for fracture analysis. Both experimental and FEA simulation show that constant CTOA criterion well predicts the adhesive thickness effect on strength of the DCB specimens for Mode I fracture failure. The failure initiation mode of single lap joint is analyzed and the constant CTOA criterion is also proven to be capable to prediction the strength of single lap joint.