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 >

Mark Pompetzki¹, Brian Dabell¹, Xiaobin Lin²

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 69-76, 2010, DOI:10.3970/sdhm.2010.006.069

Abstract Structural integrity in terms of automotive durability is a detailed process that incorporates many technical areas. The current durability process for automotive applications involves understanding operational load inputs, the stresses and strains caused and the response of the material, performing fatigue tests, calculating fatigue life and interpreting results. There are many variations on this process depending on the application, materials, available information, methods, etc. This paper presents a general approach for the durability process in automotive applications and highlights a number of new advancements. These advancements include understanding the service operating load conditions through improved usage based monitoring, characterizing new… More >

Muddasar Khan¹, Cesar Levy¹, Amer Hameed¹, Zulfiqar Khan¹, Khalid Orakzai¹, Musarrat Khan¹, Khuram Shahazad¹, Afzaal M.Malik¹, Shahab Khushnood¹

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 53-68, 2010, DOI:10.3970/sdhm.2010.006.053

Abstract Aluminum metal beverage container is used in packaging foods and chemical industries because of its superior hold, formability, corrosion resistance and join ability. The 80 percent of the container cost is material and aluminum metal is expansive one. The beverage container industry is struggling for potential saving from weight reduction in each container, while meeting the three structural performance standards which have been established to assess the adequacy of the container design. These are axial column load, drop resistance and internal pressure. This paper relates to the internal pressure standard which states that container must withstand at least 90-100PSI or… More >

I. Černý^1,2, D. Mikulová¹

Structural Durability & Health Monitoring, Vol.6, No.1, pp. 43-52, 2010, DOI:10.3970/sdhm.2010.006.043

Abstract Alternative methods of material machining like electro-erosive or water jet cutting, respectively, represent modern technologies, which are perspective to be used as final end-to-shape operations due to their possibilities of automatization and cutting precision. The paper contains results of an investigation of resistance of an aircraft AISI 4340 steel against fatigue loading performed using specimens loaded by three point bending at ambient temperature and standard laboratory conditions. Results of fatigue tests of specimens with surface after electro-erosive and water jet cutting, respectively, are presented, whereas in the latter case, areas of water jet incidence and outfall are studied separately. The… More >

M. Guagliano^1,2, S. Bagherifard², I. Fernandez Parienete³, R. Ghelichi²

Structural Durability & Health Monitoring, Vol.6, No.1, pp. 31-42, 2010, DOI:10.3970/sdhm.2010.006.031

Abstract Surface grain refinement is a relatively new process aimed to enhance mechanical material properties. In this study Al7075-T6 bars have been shot peened with parameters (shot speed and treatment duration) much stronger from those of conventional shot peening (SP). Residual stress state and microstructure gradient have been observed by means of transmission electron microscopy (TEM), X-ray diffraction (XRD) and nano indentation tester. Formation of a fine grained layer of material on top surface of the specimens was confirmed by TEM and also XRD measurements. XRD results show significant depth affected both in terms of residual stress and full width half… More >

R. Ghelichi¹, S. Bagherifard¹, I. Fernandez Parienete², M.Guagliano^1,3, Simone Vezzù⁴

Structural Durability & Health Monitoring, Vol.6, No.1, pp. 17-30, 2010, DOI:10.3970/sdhm.2010.006.017

Abstract Coating deposition processes such as cold spraying are commonly employed to increase wear and fatigue resistance and consequently to enhance longevity of engineering components. Such processes typically introduce residual stresses into the coated surface, which in turn affect efficiency of coatings and play an important role in coating durability. In fact residual stresses are the key parameter to obtain compact and well-adherent coatings. They can modify several coating properties such as adhesion, structure, toughness, hardness reflecting on the macroscopic chemical and mechanical behavior of the coating.
Present study describes alteration of residual stress state of two types of aluminum coatings… More >

M . Annoni¹, F. Arleo¹, M. Guagliano^1,2

Structural Durability & Health Monitoring, Vol.6, No.1, pp. 1-16, 2010, DOI:10.3970/sdhm.2010.006.001

Abstract This work investigates the possibility to perform Water Jet Peening (WJP) by means of a standard Water Jet (WJ) cutting plant. The experimentation is carried out on 39NiCrMo3 specimens with the aim to find out the best working conditions of two different methods: the "in air WJP" and the "submerged WJP". Comparisons between the two methods and to previous experimentations in the reference literature are also presented. More >

M. Lavella¹, T. Berruti¹

Structural Durability & Health Monitoring, Vol.5, No.4, pp. 337-350, 2009, DOI:10.3970/sdhm.2009.005.337

Abstract Results of residual stress measurements on Inconel 718 turbine components after machining are here presented. The work is focused on the experimental detection of the residual stress state produced after turning (orthogonal cutting and standard) and milling. The aim of the experimental activity was to supply an experimental data base of proved reliability for milling and turning model validation. This activity was performed inside the EU STREP project VERDI. The residual stresses were detected by means of X-ray diffraction technique. The experimental plan of measurements was performed on components worked with different working parameters (cutting velocity and feed rate) and… More >

Smitha Gopinath¹, J. Rajasankar^1,2, Nagesh R. Iyer¹, T. S. Krishnamoorthy¹, B.H.Bharatkumar¹, N. Lakshmanan¹

Structural Durability & Health Monitoring, Vol.5, No.4, pp. 311-336, 2009, DOI:10.3970/sdhm.2009.005.311

Abstract In this paper, a two-phase strain-based constitutive model is proposed for concrete under tension. First phase deals with modelling uncracked concrete while the behaviour of concrete in cracked condition is modelled in second phase with appropriate theoretical support. A bilinear tension softening curve of concrete defined in crack width-stress space is taken as the basis to propose the model. Smeared representation of reinforcement and cracks along with multi-layered geometry definition of reinforced concrete (RC) structures is used to implement the model. Through this, it is shown that change in the orientation of tensile cracks with increasing load on the structure… More >