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M. S. Alam¹, M.A. Wahab^1,2
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 171-184, 2005, DOI:10.3970/sdhm.2005.001.171
Abstract Fatigue life of curved structural joints in ship structures under constant amplitude cyclic loading has been studied in this research. A new approach for the simulation of fatigue crack growth in welded joints has been developed and the concept has been applied to welded curved butt-joints. The phenomena of crack propagation and interface debonding can be regarded as the formation of new surfaces. Thus, it is possible to model these problems by introducing the mechanism of surface formation. In the proposed method, the formation of new surface is represented by interface element based on the interface surface potential energy. The… More >

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1507

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G. Bertrand¹
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 185-192, 2005, DOI:10.3970/sdhm.2005.001.185
Abstract Each maintenance strategy demands for the definition of an inspection threshold and further inspection intervals. A general criterion for the calculation of the time to first inspection is high probability of detection of a certain crack size and low failure probability in case a predicted crack size was not detected. The proposed method demonstrates that a top down analysis of crack development from critical sizes to detectable sizes reveals an economic benefit with respect to the frequency of inspections. The dispersion of fatigue stress cycles at rupture obtained from component tests at riveted lap joints is transformed to the distribution… More >

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ARTICLE

G. Minak¹, F. E. G. Chimisso², H. S. Costa Mattos³
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 193-202, 2005, DOI:10.3970/sdhm.2005.001.193
Abstract Cyclic plasticity and damage of a metal matrix composite have been studied in the framework of continuum damage mechanics. The material was considered as macroscopically homogeneous and a model incorporating damage gradient was applied. Strain-controlled fully reversed low-cycle fatigue uniaxial tests were performed to identify material parameters related to yield stress, isotropic and kinematic hardening, fatigue life and damage diffusion. From previous studies it has been found that in the most general case the parameters of the model are constant or depend exponentially on total strain so that only two or three tests are needed for the characterisation. The results… More >

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1010

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A. Rama Ch,ra Murthy¹, G.S. Palani¹, Nagesh R. Iyer¹
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 203-214, 2005, DOI:10.3970/sdhm.2005.001.203
Abstract This paper presents an improved Wheeler residual stress model for remaining life prediction of the cracked structural components under variable amplitude loading. The improvement to the Wheeler residual stress model is in two folds. One is expressions for the shaping exponent, which are generally obtained through experiments. Another is calculation of effective plastic zone size to incorporate the sequent effects under tensile-compressive overloading. The remaining life prediction has been carried out by employing the linear elastic fracture mechanics (LEFM) principles. Studies on remaining life prediction of cracked plate panels subjected to tensile-compressive overloading have been carried out for validating the… More >

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1000

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S. Glodež¹, B. Aberšek¹, G. Fajdiga², J. Flašker²
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 215-224, 2005, DOI:10.3970/sdhm.2005.001.215
Abstract A computational model for simulation of surface and subsurface initiated fatigue crack growth due to contact loading is presented. The model is based on fracture mechanics theory where the required materials properties are obtained from common fatigue tests. For computational simulations an equivalent model of two contacting cylinders is used instead of simulating the actual contact of mechanical elements. The discretised model with the initial crack on or under the surface is then subjected to normal contact pressure, which takes into account the elasto-hydro-dynamic (EHD) lubrication conditions, and tangential loading due to friction between contacting surfaces. The model considers also… More >

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1050

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L.S. Miers¹, J.C.F. Telles²
Structural Durability & Health Monitoring, Vol.1, No.3, pp. 225-232, 2005, DOI:10.3970/sdhm.2005.001.225
Abstract The present paper aims at introducing the concept of Green's function type fundamental solutions (i.e., unit source fundamental solutions satisfying particular boundary conditions) into the context of meshless approaches, particularly dealing with the local boundary integral equation method (LBIE) derived from the classic boundary integral equation procedure. The Green's functions discussed here are mainly the so-called half-plane solution, corresponding to a unit source within a semi-plane bounded by a flux-free straight line and an infinite plane containing internal lines of potential discontinuity. The latter is here introduced in numerical fashion, as an extension of the authors' previous numerical Green's function… More >

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