Saptarshi Sasmal¹, K. Ramanjaneyulu²

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 253-282, 2011, DOI:10.3970/sdhm.2011.007.253

Abstract This paper proposes a methodology for damage detection in beam like structures using vibration characteristics obtained from transfer matrix technique. At first, vibration characteristics of beam-like structure have been determined with the help of a computer program developed based on the formulations presented in this paper. Then, a detailed study has been carried out to categorise the influence of damage on frequency and mode shape (both displacement and rotational) information. For a structure with known magnitude and location of damage(s), frequencies and mode shape information are obtained and the same has been used in determining the damage in the structure.… More >

Sangoju Bhaskar¹, Ravindra Gettu², B.H. Bharatkumar¹, M. Neelamegam¹

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 231-252, 2011, DOI:10.3970/sdhm.2011.007.231

Abstract The durability of reinforced concrete (RC) exposed to severe environments depends largely on its ability to resist the penetration of aggressive compounds. This paper deals with the corrosion of reinforcement bars (rebars) in cracked concrete exposed to chlorides. A simple U-shaped specimen was used in the study, with a high yield strength deformed bar of 12 mm diameter placed at with 20 mm clear cover. Concrete specimens with three water to cement ratios (w/c) and pre-cracks exposed to chlorides were studied for quality assessment and quantifying the corrosion damage in terms of gravimetric weight loss. Water absorption and rapid chloride… 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 many laboratories; the materials investigated… 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 this second part, the stress… 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 factor results will be presented… More >

A. Brot¹, I. Kressel¹

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 153-162, 2011, DOI:10.3970/sdhm.2011.007.153

Abstract Analysis and testing of integrally stiffened aluminum panels, reinforced by carbon-epoxy or boron-epoxy bonded strips, is described. Fatigue testing was performed at room-temperature and at -50°C. The test results show a very significant increase in the crack growth life of these panels after the reinforcement. The analytical results, based on finite-element models, correlated very well with the test results. More >

S. Hadidi-Moud^1,2, H. Makari¹

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 113-122, 2010, DOI:10.3970/sdhm.2010.006.113

Abstract A comprehensive numerical study has been carried out to investigate and to explore the impact of the presence of part through surface cracks of various size and orientation in a thick welded ferritic steel cylindrical vessel, on the beneficial effect of autofrettage loading. It is well known that autofrettage loading enhances the load carrying capacity of defect free pressure vessels. The results of this study suggest that in presence of cracks, the localised near crack tip residual stress fields interact with in service stresses and influence the enhancement in load carrying capacity of autofrettaged vessel. Furthermore it is concluded that… More >

Zihua Zhao¹, Yu Zhou, Zheng Zhang, Qunpeng Zhong

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 101-112, 2010, DOI:10.3970/sdhm.2010.006.101

Abstract Annex H"Safety assessment method for straight pressure pipeline with local thinning area" of "Safety assessment for in-service pressure vessels containing defects"(GB/T 19426-2004) is briefly introduced. The maximum allowable hanging (unsupported) length of straight pressure pipeline with a local thinning area (LTA) is then determined by using this assessment method. This is the first time that the assessment method has been applied to the long-distance oil pipeline. As a typical case, we have analyzed a length of straight pressure pipeline with LTA and gave the relationship of maximum allowable unsupported length, operating pressure and the depth of LTA. More >

Fausto Pedro García Márquez¹

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 89-100, 2010, DOI:10.3970/sdhm.2010.006.089

Abstract This paper presents a simple graphic method for detecting and classifying faults in point mechanisms based on the study of some statistical parameters of the force and current signals of the point machine. Principal Components Analysis (PCA) employed in order to reduce the number of these parameters. PCA is utilised in this paper for modifying the parameter dataset, and reducing the coordinate system by linear transformation. It is then possible to plot the new coordinate system in 2 or 3 dimensions, where the faults can be detected and identified. In this work most of the faults could be detected, but… More >

Xue-Ren Wu¹

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 77-88, 2010, DOI:10.3970/sdhm.2010.006.077

Abstract A review of the state-of-the-art is presented on the weight function method for fracture-mechanics-based structural integrity assessment with regard to crack-like defects. The weight function method provides a powerful tool for the determination of key parameters, such as stress intensity factors and crack opening displacements for cracked structural components. For two dimensional (2D) crack problems, weight functions were obtained in closed-form for both centre-and edge-crack configurations. For three dimensional(3D) cases, a combination of the closed-form 2D weight functions and the slice synthesis technique makes it possible for rapid determination of stress intensity factor at any point along the crack front.… More >