15 research outputs found

    Structural parameter identification of a bolted connection embedded with a piezoelectric interface

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    As the impedance-based technique has been commonly accepted as an innovative structural health monitoring tool, structural identification of a piezoelectric-driven system is of significant interest for damage identification and quantification. This study presents a predictive modelling strategy, which combines the finite element (FE) method with a model-updating approach, for estimating the structural parameters of a piezoelectric interface-bolted connection system. Firstly, the basic operating principle of the piezoelectric-based smart interface is introduced. Secondly, a bolted connection is selected as a host structure to conduct real impedance measurement via the smart interface. Thirdly, a numerical FE model corresponding to the experimental model is established by using a FE program, COMSOL Multiphysics. A sensitivity-based model updating algorithm is adopted to fine-tune the FE model. Finally, structural parameters of the FE model are determined as the numerical impedance signatures match with the measured ones at the same high-frequency band with identical patterns. This study is expected to open an alternative approach for determining unknown structural parameters of the piezoelectric interface-bolted joint system in practice

    Impedance-Based Pre-Stress Monitoring of Rock Bolts Using a Piezoceramic-Based Smart Washer—A Feasibility Study

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    Pre-stress degradation or looseness of rock bolts in mining or tunnel engineering threatens the stability and reliability of the structures. In this paper, an innovative piezoelectric device named a “smart washer” with the impedance method is proposed with the aim of developing a real-time device to monitor the pre-stress level of rock bolts. The proposed method was verified through tests on a rock bolt specimen. By applying high-frequency sweep excitations (typically >30 kHz) to the smart washer that was installed on the rock bolt specimen, we observed that the variation in impedance signatures indicated the rock bolt pre-stress status. With the degradation of rock bolt pre-stress, the frequency in the dominating peak of the real part of the electrical impedance signature increased. To quantify the effectiveness of the proposed technique, a normalized root mean square deviation (RMSD) index was developed to evaluate the degradation level of the rock bolt pre-stress. The experimental results demonstrated that the normalized RMSD-based looseness index, which was computed from the impedance value detected by the “smart washer”, increased with loss of the pre-stress of the rock bolt. Therefore, the proposed method can effectively detect the degradation of rock bolt pre-stress, as demonstrated by experiments

    Proceedings of the 10th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components

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    This conference, the tenth in a series on NDE in relation to structural integrity for nuclear and pressurized components, was held from 1st October to 3 October 2013, in Cannes, France. The scientific programme was co-produced by the European Commission’s Joint Research Centre, Institute for Energy and Transport (EC-JRC/IET). The Conference has been coordinated by the Confédération Française pour les Essais Non Destructifs (COFREND). The first conference, under the sole responsibility of EC-JRC was held in Amsterdam, 20-22 October 1998. The second conference was locally organized by the EPRI NDE Center in New Orleans, 24-26 May 2000, the third one by Tecnatom in Seville, 14-16 November 2001, the fourth one by the British Institute of Non-Destructive Testing in London, 6-8 December 2004, the fifth by EPRI in San Diego, 10-12 May 2006, the sixth by Marovisz in Budapest, 8-10 October 2007, the seventh by the University of Tokyo and JAPEIC in Yokohama, the eight by DGZfP, 29 September to 1st October 2010, the ninth by Epri NDE Center, 22-24 May 2012 in Seattle. The theme of this conference series is to provide the link between the information originated by NDE and the use made of this information in assessing structural integrity. In this context, there is often a need to determine NDE performance against structural integrity requirements through a process of qualification or performance demonstration. There is also a need to develop NDE to address shortcomings revealed by such performance demonstration or otherwise. Finally, the links between NDE and structural integrity require strengthening in many areas so that NDE is focussed on the components at greatest risk and provides the precise information required for assessment of integrity. These were the issues addressed by the papers selected for the conference.JRC.F.5-Nuclear Reactor Safety Assessmen

    Testing of Materials and Elements in Civil Engineering

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    This book was proposed and organized as a means to present recent developments in the field of testing of materials and elements in civil engineering. For this reason, the articles highlighted in this editorial relate to different aspects of testing of different materials and elements in civil engineering, from building materials to building structures. The current trend in the development of testing of materials and elements in civil engineering is mainly concerned with the detection of flaws and defects in concrete elements and structures, and acoustic methods predominate in this field. As in medicine, the trend is towards designing test equipment that allows one to obtain a picture of the inside of the tested element and materials. Interesting results with significance for building practices were obtained

    NASA Tech Briefs, September 1993

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    Topics include: Microelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

    Large space structures and systems in the space station era: A bibliography with indexes (supplement 05)

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    Bibliographies and abstracts are listed for 1363 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and July 31, 1992. Topics covered include technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion and solar power satellite systems

    Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

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    Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018
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