Download or read book An Observation of Crack Propagation in Anti plane Shear written by W. G. Knauss and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fractography written by Derek Hull and published by Cambridge University Press. This book was released on 1999-09-23 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: An advanced 1999 text for those working in materials science and related inter-disciplinary subjects.
Download or read book On Dynamic Transient Anti plane Shear Crack Propagation in a General Viscoelastic Layer written by John Robert Watret and published by . This book was released on 1989 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elastodynamic Crack Problems written by George C. Sih and published by Springer Science & Business Media. This book was released on 1977-03-31 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Propagation and Arrest of an Edge Crack in an Elastic Half Space Under Conditions of Anti Plane Shear Analytical and Numerical Results written by Timothy Christopher O'Sullivan and published by . This book was released on 1983 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The motion of an edge crack extending non-uniformly in an elastic half-space under conditions of anti-plane shear is analyzed. An expression for the stress intensity factor at the crack tip is obtained, and an energy balance crack propagation criterion is used to find the equation of motion of the tip. On solving this equation numerically, it is found that crack arrest occurs before the second reflected wave from the boundary reaches the tip. In the second half of this investigation, a numerical procedure for studying anti-plane shear crack propagation problems using finite differences is developed. To approximate the elastodynamic field as accurately as possible near the moving crack tip, where singular stresses occur, the local asymptotic displacement field near the tip is incorporated into the finite difference scheme. The numerical procedure is applied to the edge crack problem analyzed in the first part of this study, and the numerical and exact results are compared. (Author).
Download or read book Mechanics of Fracture Initiation and Propagation written by George C. Sih and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: The assessment of crack initiation and/or propagation has been the subject of many past discussions on fracture mechanics. Depending on how the chosen failure criterion is combined with the solution of a particular theory of continuum mechanics, the outcome could vary over a wide range. Mod elling of the material damage process could be elusive if the scale level of observation is left undefined. The specification of physical dimension alone is not sufficient because time and temperature also play an intimate role. It is only when the latter two variables are fixed that failure predictions can be simplified. The sudden fracture of material with a pre-existing crack is a case in point. Barring changes in the local temperature,* the energy released to create a unit surface area of an existing crack can be obtained by considering the change in elastic energy of the system before and after crack extension. Such a quantity has been referred to as the critical energy release rate, G e, or stress intensity factor, K Ie. Other parameters, such as the crack opening displacement (COD), path-independent J-integral, etc. , have been proposed; their relation to the fracture process is also based on the energy release concept. These one-parameter approaches, however, are unable simultaneously to account for the failure process of crack initiation, propagation and onset of rapid fracture. A review on the use of G, K I, COD, J, etc. , has been made by Sih [1,2].
Download or read book Numerical Assessments of Cracks in Elastic Plastic Materials written by Huang Yuan and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book a systematic discussion of crack problems in elastic-plastic materials is presented. The state of the art in fracture mechanics research and assessment of cracks is documented, with the help of analytic, asymptotic methods as well as finite element computations. After a brief introduction to fracture mechanics, the two-parameter concept for stationary cracks is studied in addition to the issues in three-dimensional crack fields under coupling with strong out-of-plane effects. Cracks along interfaces and crack growth problems under mixed mode conditions are also treated. A systematic study of stress singularities for different notches is accompanied by detailed finite element computations.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamic Growth of an Antiplane Shear Crack in a Rate Sensitive Elastic Plastic Material written by LB. Freund and published by . This book was released on 1983 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical study of the dynamic steady-state antiplane shear (Mode III) crack growth process is described. The study is based on continuum mechanics, and the material is modeled as being elastic-viscoplastic. Using the small-scale yielding concept of fracture mechanics and allowing only for steady-state crack growth, but including the effects of material inertia explicitly, a full-field solution for the deformations is obtained by means of an iteration procedure involving the finite-element method. Numerical results for the strain distribution in the active plastic zone are presented. The fracture criterion for materials which fail in a locally ductile manner proposed by McClintock and Irwin [1],3 which stipulates that crack growth will proceed such that a critical strain level is maintained at a characteristic distance ahead of the crack tip, is adopted. This criterion is coupled with the results of numerical calculations to develop theoretical dynamic fracture toughness versus crack tip speed relationships for two levels of critical strain. For rate-dependent materials a range of toughness-versus-speed relations is manifested, ranging from that similar to rate-independent materials for low rate sensitivity to a relationship which rises dramatically for even a small increase in crack speed at low crack speeds, but which levels off for higher speeds for extremely rate-sensitive materials.
Download or read book Crack Propagation Theories written by Fazil Erdogan and published by . This book was released on 1967 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article consists of two parts. In the first part, the crack propagation theories for brittle and quasi-brittle solids fracturing under a single application of the external loads are considered. The emphasis has been on the dynamic aspects of the fracture phenomenon and the related quantitative theories. Thus, the problem is discussed only from the viewpoint of continuum mechanics and classical thermodynamics. Two theoretical approaches are presented in detail. These are the dynamic crack propagation theory based on the concept of modulus of cohesion proposed by Barenblatt and various forms of the energy balance theory based essentially on the ideas proposed by Griffith. A detailed analysis of the energy balance around the periphery of the crack is given and it is shown that the energy available at the crack periphery to create new fracture surfaces is equivalent to the crack closure energy, which is different from the released strain energy if the inertia effects are not negligible. The results are applied to plane extensional and anti-plane shear problems. The techniques used in and the results obtained from the available experimental studies are then discussed.
Download or read book Mechanics Today written by S. Nemat-Nasser and published by Elsevier. This book was released on 2013-10-22 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanics Today, Volume 4 focuses on solid mechanics and applied mathematics. This book is divided into six chapters. Chapter I provides a general description of the basic features and relevant concepts of mixed boundary-value problems in mechanics. The problem of crack extension in a solid under arbitrary loads is discussed in Chapter II, emphasizing the crack growth that leads from a planar to a nonplanar configuration. The third chapter reviews various methods of solving the scattering of elastic waves by inclusions. The interactions of electromagnetic field with deformable bodies in motion are elaborated in Chapter IV, while problems involving solids carrying high electric currents or being placed in high magnetic fields are deliberated in Chapter V. The last chapter concentrates on the implications of the second law of thermodynamics, and consequences of thermodynamic material stability and its corresponding restrictions on the evolutionary equations for internal variables. This publication is useful to specialists, but is also beneficial to non-experts with sufficient background in applied mechanics.
Download or read book Fracture Mechanics written by Society for Industrial and Applied Mathematics and published by American Mathematical Soc.. This book was released on 1979 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Dynamic Steady State Propagation of an Anti Plane Shear Crack in a General Linearly Viscoelastic Layer written by J. R. Walton and published by . This book was released on 1984 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous paper, the dynamic, steady-state propagation of an semi-infinite anti-plane shear crack was considered for an infinite, general linearly viscoelastic body. Under the assumptions that the shear modulus is a positive, non-increasing continuous and convex function of time, convenient, closed-from expressions were derived for the stress intensity factor and for the entire stress distribution ahead of and in the plane of the advancing crack. The solution was shown to have a simple universal dependence upon the shear modulus and crack speed from which qualitative information can readily be gleaned. Here, the corresponding problem for a general, linearly viscoelastic layer is solved. An infinite series representation for the stress intensity factor is derived, each term of which can be calculated recursively in closed-form. As before, a simple universal dependence upon crack speed and material properties is exhibited. (Author).
Download or read book Boundary Value Problems in Linear Viscoelasticity written by John M. Golden and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The classical theories of Linear Elasticity and Newtonian Fluids, though trium phantly elegant as mathematical structures, do not adequately describe the defor mation and flow of most real materials. Attempts to characterize the behaviour of real materials under the action of external forces gave rise to the science of Rheology. Early rheological studies isolated the phenomena now labelled as viscoelastic. Weber (1835, 1841), researching the behaviour of silk threats under load, noted an instantaneous extension, followed by a further extension over a long period of time. On removal of the load, the original length was eventually recovered. He also deduced that the phenomena of stress relaxation and damping of vibrations should occur. Later investigators showed that similar effects may be observed in other materials. The German school referred to these as "Elastische Nachwirkung" or "the elastic aftereffect" while the British school, including Lord Kelvin, spoke ofthe "viscosityofsolids". The universal adoption of the term "Viscoelasticity", intended to convey behaviour combining proper ties both of a viscous liquid and an elastic solid, is of recent origin, not being used for example by Love (1934), though Alfrey (1948) uses it in the context of polymers. The earliest attempts at mathematically modelling viscoelastic behaviour were those of Maxwell (1867) (actually in the context of his work on gases; he used this model for calculating the viscosity of a gas) and Meyer (1874).
Download or read book On the Energy Release Rate for Dynamic Transient Anti Plane Shear Crack Propagation in a General Linear Viscoelastic Body written by J. M. Herrmann and published by . This book was released on 1987 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of a semi-infinite mode III crack that suddenly begins to propagate at a constant speed is considered for a general linear viscoelastic body. Simple closed form expressions are derived for the Laplace transform of the stress, displacement, and stress intensity factor. A Barenblatt type failure zone is assumed to exist at the crack tip and an expression for the total energy flux into the failure zone per unit crack advance, G(t), is derived. The short time asymptotic form of G is constructed and the rate at which it converges to its steady-state limit is studied. It is shown that the rate of convergence to steady-state is dependent upon crack speed and material properties. (jes).
Download or read book Rock Mechanics Tools and Techniques written by Michel Aubertin and published by Taylor & Francis US. This book was released on 1996 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of Crack Paths CP 2009 Vicenza Italy 2009 written by and published by Gruppo Italiano Frattura. This book was released on with total page 1129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
