P.H. Wen¹, M.H. Aliabadi²

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 223-248, 2012, DOI:10.32604/sdhm.2012.008.223

Abstract A mesh-free method for modelling crack growth in functionally graded materials is presented. Based on the variational principle of the potential energy, mesh-free method has been implemented with enriched radial bases interpolation functions to evaluate mixed-mode stress intensity factors, which are introduced to capture the singularity of stress at the crack tip. Paris law and the maximum principle stress criterion are adopted for defining the growth rate and direction of the fatigue crack growth respectively. The accuracy of the proposed method is assessed by comparison to other available solutions. More >

A. Ramachandra Murthy¹, Nagesh R. Iyer¹, B.K. Raghu Prasad²

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.6, pp. 459-480, 2012, DOI:10.3970/cmes.2012.089.459

Abstract This paper presents the details of crack growth study and remaining life assessment of concrete specimens made up of high strength concrete (HSC, HSC1) and ultra high strength concrete (UHSC). Flexural fatigue tests have been conducted on HSC, HSC1 and UHSC beams under constant amplitude loading with a stress ratio of 0.2. It is observed from the studies that (i) the failure patterns of HSC1 and UHSC beams indicate their ductility as the member was intact till the crack propagated up to 90% of the beam depth and (ii) the remaining life decreases with increase… More >

Dennis Bäcker¹, Andreas Ricoeur², Meinhard Kuna¹

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 1-22, 2011, DOI:10.3970/sdhm.2011.007.001

Abstract A new sensor concept for monitoring fatigue crack growth in technical structures is presented. It allows the in-situ determination of the position of the crack tip as well as the fracture mechanical quantities. The required data are obtained from a piezoelectric polymer film, which is attached to the surface of the monitored structure. The stress intensity factors and the crack tip position are calculated from electrical potentials obtained from a sensor array by solving the non-linear inverse problem. More >

A. Lanciotti, L. Lazzeri¹, C. Polese², C. Rodopoulos³, P. Moreira^4,5, A. Brot⁶, G. Wang⁷, L. Velterop⁸, G. Biallas⁹, J. Klement

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 211-230, 2011, DOI:10.3970/sdhm.2011.007.211

Abstract An experimental activity was performed to collect test data on the fatigue crack propagation in various types of specimens, within the DaToN research project, partly funded by the EU in the FP6 programme. Only one general configuration was used, i.e. flat panels with two blade stringers, with different options for the manufacturing processes, that could be integral or welded. The purpose of this test activity was to obtain useful results for the validation and calibration of prediction methodologies, also developed in the same DaToN research project. A wide experimental programme was defined and performed by More >

S.M.O. Tavares¹, S.M. Häusler², P.M. Baiz³, P.M.S.T. de Castro¹, P. Horst² , M.H. Aliabadi³

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 191-210, 2011, DOI:10.3970/sdhm.2011.007.191

Abstract This article is the second part of a two parts paper which presents, compares and discusses the different crack growth simulation models which were introduced for fatigue crack growth assessment during the DaToN project. In the first part, different simulation approaches were applied to determine a calibration of the stress intensity factors as a function of the crack length for a two stiffeners panel with a central crack. Due to the residual stress field promoted by the different manufacturing processes, its influence was included in the numerical models to determine the stress intensity factors. In… More >

S.M. Häusler¹, P.M. Baiz², S.M.O. Tavares³, A. Brot⁴, P. Horst¹, M.H. Aliabadi², P.M.S.T. de Castro³, Y. Peleg-Wolfin⁴

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 163-190, 2011, DOI:10.3970/sdhm.2011.007.163

Abstract This article represents the first part of a two-part article which presents, compares and discusses the different crack growth simulation models which were introduced for fatigue crack growth assessment during the DaToN project. The project was funded by the EC within the 6th framework program and was specifically devoted to investigate innovative manufacturing techniques for metallic structures with special focus on the effects of residual stresses on the fatigue crack growth and residual strength behaviour. Within this first part the different simulation approaches, including the residual stress modelling approaches will be introduced and stress intensity… More >

A.P.Cisilino¹, M.H. Aliabadi²

Structural Durability & Health Monitoring, Vol.6, No.3&4, pp. 213-238, 2010, DOI:10.3970/sdhm.2010.006.213

Abstract This paper presents a review of the dual boundary element method for modeling crack growth in two-dimensional and three-dimensional mixed mode problems. The modeling strategy for crack coalescence using the DBEM is presented and comparisons are made with alternative solutions where available. Also presented are three-dimensional multiple crack growth and microcrack growth problems. More >

S. Abdullah¹, S. M. Beden, A. K. Ariffin, N. A. Al-Asady

Structural Durability & Health Monitoring, Vol.5, No.2, pp. 109-132, 2009, DOI:10.3970/sdhm.2009.005.109

Abstract This paper presents a study on fatigue crack growth modelling of thin walled tube aluminium alloy with circumferential crack under constant and variable amplitude loadings. Three fatigue crack growth models were investigated for this purpose, i.e. Walker, Forman and NASGRO. The results showed the differences in the fatigue crack growth simulation under both loading types, although, they have the same stress ratio for the maximum value. Subsequently, it was found that, different models gave different fatigue crack growth behaviour. In another case, many factors were identified towards the fatigue crack growth affection in structures. Hence, More >

Ivo Černý¹, Václav Linhart²

Structural Durability & Health Monitoring, Vol.5, No.1, pp. 73-86, 2009, DOI:10.3970/sdhm.2009.005.073

Abstract The experimental programme described in the paper was aimed at an evaluation of fatigue crack growth (FCG) rate and threshold conditions in a reactor pressure vessel steel in laboratory air and in simple aqueous environment. Though the main target of the work was to enlarge the data basis for possible future needs of defect and risk assessment, an emphasis was put on an evaluation of crack growth mechanisms. It was shown that despite some recent works infirming crack closure phenomenon itself or methods of its evaluation, crack closure explained near-threshold fatigue crack behaviour in the More >

S. M. Beden¹, S. Abdullah¹, A. K. Ariffin¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 41-50, 2009, DOI:10.3970/icces.2009.010.041

Abstract Fatigue crack growth as consequence of service loads depends on many different contributing factors. This paper describes the fatigue crack growth behavior of metallic materials under cyclic loading towards standardizing the fatigue crack studies on metallic materials. For the simulation purpose, three points bend (TPB) with span to width ratio 8:1 and compact tension (CT) specimens geometry were used. There are many factors affecting the fatigue crack growth in structures, such as fatigue crack growth model, stress ratio, aspect ratio and type of geometry. The behavior of such cases is shown using different fatigue crack More >