Influence of magnetostrictive strip size in the generation of L(0,2) and T(0,1) wave mode using magnetostrictive patch transducer (MPT)
01 May 2019-Vol. 2102, Iss: 1, pp 050023
About: The article was published on 2019-05-01 and is currently open access. It has received 2 citations till now. The article focuses on the topics: Transducer.
Citations
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TL;DR: In this article, an in-bore magnetostrictive transformer was used to examine the integrity of a steam generator tube of a nuclear reactor for smooth operation of steam generators.
Abstract: Periodic assessment of steam generator tubes of a sodium-cooled nuclear reactor is very crucial for smooth operation of steam generators. To examine the integrity, an in-bore magnetostrictive trans...
4 citations
Cites background from "Influence of magnetostrictive strip..."
...However, with magnetostrictive patch transducers (MPTs), ultrasonic waves can be generated in non-ferromagnetic specimens through the transfer of strains developed in MPTs via mechanical bonding.(23) An important parameter that needs to be considered in the design of an MsT is the bias magnetic field....
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TL;DR: In this article , the Staircase Magnetostrictive Patch (ScaMP) transducer was proposed for wall thickness reduction, which typically results from corrosion, erosion, or operating conditions.
Abstract: Wall thickness reduction, which typically results from corrosion, erosion, or operating conditions, is a significant challenge in many industries. In order to generate a broadband pure shear horizontal wave mode in plate structures, this paper proposes a magnetostrictive patch transducer called the Staircase Magnetostrictive Patch (ScaMP) Transducer. For ScaMP transduction, an optimised patch width offers a broadband frequency response is employed. The lowest remnant thickness of the sample was estimated using the wideband SH1 dispersive guided wave mode's cut-off property. The broad frequency excitation method enabled measurement over a range of wall thinning up to 80% of the nominal thickness with a single data acquisition. Experiments were carried out on an 8 mm nominal wall thickness aluminium plate with gouge defects to evaluate the proposed sensor's broad frequency response. The measurement of remnant thickness was estimated with a maximum error of 5.5%.
References
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TL;DR: A variety of state-of-the-art MPT configurations and their applications will be reviewed along with the working principle of this transducer type.
200 citations
TL;DR: A description is given of its various scientific and engineering applications, including the study of wave dispersion in structures, global and long-range inspection of steel pipes and tubes, condition monitoring of machinery such as combustion engines, and onboard sensing of crash events for vehicle safety system operations.
193 citations
TL;DR: A finite element model of the elementary transducers has been developed and shows that magnetostrictive EMATs directly applied on mild steel plates have comparatively poor performance that is dependent on the precise magneto-mechanical properties of the test object.
Abstract: Guided wave inspection has proven to be a very effective method for the rapid inspection of large structures. The fundamental shear horizontal (SH) wave mode in plates and the torsional mode in pipe-like structures are especially useful because of their non-dispersive character. Guided waves can be generated by either piezoelectric transducers or electro- magnetic acoustic transducers (EMATs), and EMATs can be based on either the Lorentz force or magnetostriction. Several EMAT configurations can be used to produce SH waves, the most common being Lorentz-force periodic permanent magnet and magnetostrictive EMATs, the latter being directly applied on the sample or with a bonded strip of highly magnetostrictive material on the plate. This paper compares the performance of these solutions on steel structures. To quantitatively assess the wave amplitude produced by different probes, a finite element model of the elementary transducers has been developed. The results of the model are experimentally validated and the simulations are further used to study the dependence of ultrasonic wave amplitude on key design parameters. The analysis shows that magnetostrictive EMATs directly applied on mild steel plates have comparatively poor performance that is dependent on the precise magneto-mechanical properties of the test object. Periodic permanent magnet EMATs generate intermediate wave amplitudes and are noncontact and insensitive to the variations in properties seen across typical steels. Large signal amplitudes can be achieved with magnetostrictive EMATs with a layer of highly magnetostrictive material attached between the transducer and the plate, but this compromises the noncontact nature of the transducer.
149 citations
TL;DR: Magnetic and magnetostrictive sensor configurations are compared and contrasted in terms of application, sensitivity, and implementation issues as discussed by the authors, and compared to other common sensor configurations as appropriate.
Abstract: As sensors become integrated in more applications, interest in magnetostrictive sensor technology has blossomed. Magnetostrictive sensors take advantage of the efficient coupling between the elastic and magnetic states of a material to facilitate sensing a quantity of interest. Magnetic and magnetostrictive theory pertinent to magnetostrictive sensor technology is provided. Sensing configurations are based on the utilization of a magnetostrictive element in a passive, active, or combined mode. Magnetostrictive sensor configurations that measure motion, stress or force, torque, magnetic fields, target characteristics, and miscellaneous effects are discussed. The configurations are compared and contrasted in terms of application, sensitivity, and implementation issues. Comparisons are made to other common sensor configurations as appropriate. Experimental and modeling results are described when available and schematics of the configurations are presented.
143 citations
TL;DR: A new magnetostrictive transducer configuration using several pieces of nickel strips installed at 45 degrees with respect to the pipe axis to improve the transduction efficiency and to avoid the cumbersome premagnetization is proposed.
Abstract: For the efficient long-range nondestructive structural health inspection of pipes, guided waves have become widely used. Among the various guided wave modes, the torsional wave is most preferred since its first branch is nondispersive. Our objective in this work is to develop a new magnetostrictive transducer configuration to transmit and receive torsional waves in cylindrical waveguides. The conventional magnetostrictive transducer for the generation and measurement of torsional waves consists of solenoid coils and a nickel strip bonded circumferentially to test pipes. The strip must be premagnetized by a permanent magnet before actual measurements. Because of the premagnetization, the transducer is not suitable for the long-term on-line monitoring of pipes buried underground. To avoid the cumbersome premagnetization and to improve the transduction efficiency, we propose a new transducer configuration using several pieces of nickel strips installed at 45° with respect to the pipe axis. If a static bias magnetic field is also applied, the transducer output can be substantially increased. Several experiments were conducted to study the performance of the proposed transducer configuration. The proposed transducer configuration was also applied for damage detection in an aluminum pipe.
97 citations