Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (21,909)
  • Open Access

    ARTICLE

    Fatigue Resistance and Cracking Mechanisms in an Aircraft AISI 4340 Steel with Surface Affected by Electro-Erosive and Water Jet Cutting

    I. Černý1,2, 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 >

  • Open Access

    ARTICLE

    Assessment of Severe Shot Peening on Surface Characteristics of Al Alloys

    M. Guagliano1,2, 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 >

  • Open Access

    ARTICLE

    Experimental Study of Shot Peening Followed by Cold Spray Coating on Residual Stresses of the Treated Parts

    R. Ghelichi1, S. Bagherifard1, I. Fernandez Parienete2, M.Guagliano1,3, 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 >

  • Open Access

    ARTICLE

    Water Jet Peening of a Low-Alloy Steel by Means of a Standard Water Jet Cutting Machine Under Different Process Conditions

    M . Annoni1, F. Arleo1, M. Guagliano1,2

    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 >

  • Open Access

    ARTICLE

    The Residual Stress State Due to Machining of Turbine Components: Experimental Investigation

    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 >

  • Open Access

    ARTICLE

    A Strain-Based Constitutive Model for Concrete under Tension in Nonlinear Finite Element Analysis of RC Flexural Members

    Smitha Gopinath1, J. Rajasankar1,2, 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 >

  • Open Access

    ARTICLE

    Development of a Portable Integrated Wireless Sensor Module for Structural Damage Monitoring

    Ramana M. Pidaparti1, Ashwin Belle2, Ju Wang3

    Structural Durability & Health Monitoring, Vol.5, No.4, pp. 295-310, 2009, DOI:10.3970/sdhm.2009.005.295

    Abstract This paper presents the development of a portable integrated wireless sensor module with video camera and ultrasound capabilities to monitor and investigate corrosion damage "in" structures. There are many studies in the literature on structural health monitoring with various sensors systems. However, very few of them utilize low power devices with reliable wireless communication capability to support data-intensive sensing which is a critical issue for practical applications. In this study, we developed a wireless sensor module with video camera capabilities and integrated it with a damage analysis module to investigate the damage of a structure. The module provides an open… More >

  • Open Access

    ARTICLE

    Theoretical Time Evolution of Critical Chloride Content in Concrete

    I.S. Yoon1, E.A.B. Koenders2

    Structural Durability & Health Monitoring, Vol.5, No.4, pp. 275-294, 2009, DOI:10.3970/sdhm.2009.005.275

    Abstract The critical chloride content for corrosion initiation is a crucial parameter in determining the durability and integrity of reinforced concrete structures, however, the value is still ambiguous. Most studies reporting the critical threshold of the chloride content have involved experimental measurements of the average amount of the total chloride content at an arbitrary time. Although carbonation can significantly impact on critical threshold chloride content, the majority of the researches have not dealt with this issue in combination with carbonation of concrete. Furthermore, many studies have tried to define the critical chloride content within the scope of their experimental concrete mix… More >

  • Open Access

    ARTICLE

    Structures with Surface-Bonded PZT Piezoelectric Patches: a BEM Investigation into the Strain-transfer Mechanism for SHM applications

    I. Benedetti1, A. Milazzo1, M.H. Aliabadi2

    Structural Durability & Health Monitoring, Vol.5, No.3, pp. 251-274, 2009, DOI:10.3970/sdhm.2009.005.251

    Abstract In this work a three-dimensional BEM model is used for the analysis of structures with cracks and surface bonded piezoelectric PZT patches used as strain sensors. The cracked structure is modelled by the dual boundary element method, which allows for accurate and reliable crack analysis, while the piezoelectric patch is analyzed by a finite element state-space approach, that embodies both the full electro-mechanical coupling and the suitable sensor's boundary conditions. The model is used to investigate the strain-transfer mechanism from an host elastic structure to the piezoelectric layer, taking into account the effect of the adhesive layer, as well as… More >

  • Open Access

    ARTICLE

    Unsupervised Time-series Fatigue Damage State Estimation of Complex Structure Using Ultrasound Based Narrowband and Broadband Active Sensing

    S.Mohanty1, A. Chattopadhyay2, J. Wei3, P. Peralta4

    Structural Durability & Health Monitoring, Vol.5, No.3, pp. 227-250, 2009, DOI:10.3970/sdhm.2009.005.227

    Abstract This paper proposes unsupervised system identification based methods to estimate time-series fatigue damage states in real-time. Ultrasound broadband input is used for active damage interrogation. Novel damage index estimation techniques based on dual sensor signals are proposed. The dual sensor configuration is used to remove electrical noise, as well as to improve spatial resolution in damage state estimation. The scalar damage index at any particular damage condition is evaluated using nonparametric system identification techniques, which includes an empirical transfer function estimation approach and a correlation analysis approach. In addition, the effectiveness of two sensor configurations (configuration 1: sensors placed near… More >

Displaying 16471-16480 on page 1648 of 21909. Per Page