by Rubinstein, Asher A.; Tang, Yaliang

After a relatively short time in service, components with thermal barrier coatings (TBCs) protection typically develop a system of cracks that propagate from the coated surface toward the interface. Usually these cracks propagate across the thickness of the protective coating and branch along the interface between the coating and the bank metal. The presence of these crack nets is a concern for the durability of the components with TBCs. In the study of thin TBCs by Rubinstein and Tang (Int J Solids Struct 42:5831–5847, 2005), it was found that in a number of cases, these components may still serve for a long time because of crack growth resistance development for cracks growing

by Goldstein, Robert V.

DOI: 10.1007/s10704-008-9252-0
Online Date: 7/31/2008
Print publication date: 3/1/2008
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by Makhutov, N. A.; Gadenin, M. M.

The equations of an elasto-plastic static and cyclic deformation at high temperature, force and deformation criteria of quasistatic and fatigue failures, criterion of initiation and propagation of cracks, features of the equations for linear and nonlinear fracture mechanics are described. The mechanics of a nonlinear deformation and fracture is used for calculations of strength, life-time and crack resistance of constructions at high temperature.

DOI: 10.1007/s10704-008-9230-6
Online Date: 7/29/2008
Print publication date: 3/1/2008
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by Kashtanov, A. V.; Petrov, Yu. V.; Pugno, N.; Carpinteri, A.

A new approach describing the dynamic fracture as a process of nucleation and subsequent propagation of a nonlinear wave of microfracture is proposed. The equation describing the microfracture evolution is derived from the transfer equation and a stochastic diffusion-type description of damage redistribution. The physical meaning of the corresponding parameters is clarified by the mass conservation and the incubation time criterion of fracture. Finally the process of dynamic macrocrack nucleation is simulated.

DOI: 10.1007/s10704-008-9223-5
Online Date: 7/29/2008
Print publication date: 3/1/2008
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by Reyes, E.; Casati, M. J.; Gálvez, J. C.

This paper presents a numerical procedure for mixed mode fracture of brickwork masonry. The model is an extension of the cohesive model prepared by the authors for concrete, and takes into account the anisotropy of the material. After the crack path is obtained, an interface finite element (using the cohesive fracture model) is incorporated into the trajectory. Such a model is then implemented into a commercial code by means of a user subroutine, consequently being contrasted with experimental results. Fracture properties of masonry are independently measured for two directions on the composed masonry, and then input in the numerical model. This numerical procedure accurately predicts the experimental mixed mode

by Rungamornrat, Jaroon; Mear, Mark E.

A weakly singular, symmetric Galerkin boundary element method (SGBEM) is established to compute stress and electric intensity factors for isolated cracks in three-dimensional, generally anisotropic, piezoelectric media. The method is based upon a weak-form integral equation, for the surface traction and the surface electric charge, which is established by means of a systematic regularization procedure; the integral equation is in a symmetric form and is completely regularized in the sense that its integrand contains only weakly singular kernels of $${\mathcal{O}(1/r)}$$ (hence allowing continuous interpolations to be employed in the numerical approximation). The weakly singular kernels which appear in the weak-form integral equation are expressed explicitly, for general anisotropy, in terms of a

by Weber, W.; Steinmann, P.; Kuhn, G.

The continuous growth of 3D cracks under cyclic loading conditions is considered within a discrete simulation procedure. It is performed within the framework of linear elastic fracture mechanics. An incremental procedure is applied to consider the non-linear behavior of crack growth within the simulation. In each increment the direction and magnitude of the crack propagation for each point along the crack front are needed to define the new crack front. Within the present context the crack deflection results from the maximum tangential stress criterion and the crack extension is obtained by the evaluation of a crack propagation rate. To simulate the crack propagation as exactly as possible the evolution of the

by Papadopoulos, G. A.; Badalouka, B.; Souyiannis, J.

Patch repair of cracked structures has become a rapidly grown technology. The major function of a repair is to reduce the stress intensity factor at the crack-tip. Calculation of stress intensity factor of a repaired crack has been performed by analytical and numerical methods. However, these methods are based on simplifying assumptions regarding material behavior and repair conditions. In the present paper an experimental and an numerical determination of mode-I stress intensity factor (SIF), KI at the tip of an edge crack reinforced with bonded patches is undertaken by using the optical method of caustics and the finite element analysis (FEA). The experimental method of caustics is simple in its

by Mikulik, Zoltan; Kelly, Donald W.; Prusty, B. Gangadhara; Thomson, Rodney S.

The behaviour of a composite test specimen with an embedded delamination subjected to transverse tension has been investigated through experimental testing and finite element (FE) analyses. The testing program consisted of specimens in two geometrical configurations; square and rectangular delamination. The initiation and growth of the delamination was numerically predicted by fracture mechanics. FE models were analysed with both MSC.Nastran and Abaqus FE codes. The MSC.Nastran model was used to calculate strain energy release rates employing a crack tip element methodology. The Abaqus model was evaluated using the virtual crack closure technique. Both approaches accurately predicted failure initiation locations as observed in the test specimens. Failure