Open Access

ARTICLE

A. Brasiliano¹, W.R. Souza², G.N. Doz³, J.L.V. Brito⁴
Structural Durability & Health Monitoring, Vol.4, No.2, pp. 53-66, 2008, DOI:10.3970/sdhm.2008.004.053
Abstract It can be observed that usually, during structures useful life they are submitted to deterioration processes that, depending on the intensity, may affect their performance and load capacity and, as a result, their safety. In this case, it is necessary to accomplish an inspection in order to evaluate the conditions of the structure and to locate and quantify the intensity of the damage. Another important point is to study the behavior of brittle material beams with cracks, as an attempt of understanding the rupture mechanism and crack propagation phenomenon. In this paper, the Residual Error More >

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1166

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ARTICLE

C. Colombo¹, M. Guagliano^1,2, L. Vergani¹
Structural Durability & Health Monitoring, Vol.4, No.2, pp. 67-76, 2008, DOI:10.3970/sdhm.2008.004.067
Abstract With the aim of experimentally assessing the stress intensity factors under mixed-mode loading along a crack front, the case of an internal elliptical crack is analyzed. An experimental test is performed on a three-dimensional photoelastic model made in epoxy resin. This model contains an inner natural crack, created by thermal shock. The crack is inclined in the cylindrical model, loaded with a tensile stress field.
Exploiting the characteristics of the epoxy resin, and using the stress freezing technique, it is possible to keep memory of the stresses near to the crack tip, once the specimen is unloaded. More >

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1127

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ARTICLE

G.S. Palani¹, B. Dattaguru², Nagesh R. Iyer¹
Structural Durability & Health Monitoring, Vol.4, No.2, pp. 77-94, 2008, DOI:10.3970/sdhm.2008.004.077
Abstract The objective of this paper is to present a generalized technique called as, numerically integrated Modified Virtual Crack Closure Integral (NI-MVCCI) technique for computation of strain energy release rate (SERR) for 2-D crack problems employing singular finite elements. NI-MVCCI technique is generalized one and the expressions for computing SERR are independent of the finite element employed. Stress intensity factor (SIF) can be computed using the relations between SERR and SIF depending on the assumption of plane stress/strain conditions. NI-MVCCI technique has been demonstrated for 8-noded Serendipity (regular & quarter-point) and 9-noded Lagrangian (regular & quarter-point) More >

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1594

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1196

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ARTICLE

B. M. Singh, J. Rokne, R. S. Dhaliwal¹
Structural Durability & Health Monitoring, Vol.4, No.2, pp. 95-106, 2008, DOI:10.3970/sdhm.2008.004.095
Abstract Under the permeable electric boundary condition the problem of two collinear anti-plane shear cracks situated at the interface of two bonded dissimilar piezoelectric layers is considered. It is assumed that applied longitudinal shear stress and electric loading at the layer surfaces are prescribed. By the use of Fourier transforms we reduce the problem to solving a set of triple integral equations with a cosine kernel. The triple integral equations are further reduced to a Fredholm integral equation of the second kind whose iterative solution has been obtained. Analytical expressions for the stress intensity factors are More >

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1492

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1155

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J. Useche, P. Sollero, E.L. Albuquerque¹, L. Palermo²
Structural Durability & Health Monitoring, Vol.4, No.2, pp. 107-116, 2008, DOI:10.3970/sdhm.2008.004.107
Abstract The fracture analysis of cracked thick plates repaired with adhesively bonded composite patches using a boundary element formulation is presented. The shear deformable cracked isotropic plate was modeled using the dual boundary method. In order to model the repair, a three parameter boundary element formulation was established. This formulation is based on Kirchhoff's theory for symmetric layer composite plates and considers the transversal deflection and two in-plane rotations. Interaction forces and moments between the cracked plate and the composite repair were modeled as distributed loading, and discretized using continuous and semi-discontinuous domain cells. Coupling equations, More >

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1122