scholarly journals Fast Measurement of Magnetostriction Coefficients for Silicon Steel Strips Using Magnetostriction-Based EMAT

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4495 ◽  
Author(s):  
Weiping Ren ◽  
Ke Xu ◽  
Peng Zhou
Keyword(s):  
Element Model ◽  
Silicon Steel ◽  
Ultrasonic Waves ◽  
Optical Methods ◽  
Maximum Efficiency ◽  
Electromagnetic Acoustic Transducer ◽  
Steel Strips ◽  
Offline Measurement ◽  
Lift Off ◽  
Magnetostriction Coefficient

Strain gauges and optical methods are commonly used to measure the magnetostriction coefficient of a sample. All these methods require a specific size sample and can only realize offline measurement, which is time-consuming. Therefore, we propose a new method using a magnetostriction-based electromagnetic acoustic transducer (EMAT) to measure the magnetostriction coefficient. The amplitude of the ultrasonic waves generated by the EMAT is applied to characterize the magnetostriction coefficient of a sample. A nonlinear magnetostriction finite element model is established, and the simulation results show that the amplitude of the ultrasonic wave generated by the magnetostriction-based EMAT is proportional to the magnetostriction coefficient of the material. Experiments are carried out on silicon steel strips with different silicon contents. The results show that the method can effectively measure their relative magnetostriction coefficients. Furthermore, the structure of the magnetostriction-based EMAT is optimized to maximize efficiency. The excitation and receiving transducers reach their maximum efficiency when the static magnetic flux densities are 3.5 mT and 6.8 mT, respectively. Moreover, the relative error caused by the vibration reaches the minimal size when the lift-off of the receiving coil is set to 3 mm around. This method is fast and can be applied to online measurement.

scholarly journals A Novel Impedance Micro-Sensor for Metal Debris Monitoring of Hydraulic Oil

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 150
Author(s):  
Hongpeng Zhang ◽  
Haotian Shi ◽  
Wei Li ◽  
Laihao Ma ◽  
Xupeng Zhao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Wear Debris ◽  
Detection Method ◽  
Silicon Steel ◽  
Detection Sensitivity ◽  
Normal Operation ◽  
Metal Debris ◽  
Hydraulic Oil ◽  
Steel Strips ◽  
The Magnetic Field

Hydraulic oil is the key medium for the normal operation of hydraulic machinery, which carries various wear debris. The information reflected by the wear debris can be used to predict the early failure of equipment and achieve predictive maintenance. In order to realize the real-time condition monitoring of hydraulic oil, an impedance debris sensor that can detect inductance and resistance parameters is designed and studied in this paper. The material and size of wear debris can be discriminated based on inductance-resistance detection method. Silicon steel strips and two rectangular channels are designed in the sensor. The silicon steel strips are used to enhance the magnetic field strength, and the double rectangular detection channels can make full use of the magnetic field distribution region, thereby improving the detection sensitivity and throughput of the sensor. The comparison experiment shows that the coils in series are more suitable for the monitoring of wear debris. By comparing and analyzing the direction and the presence or absence of the signal pulses, the debris sensor can detect and distinguish 46 µm iron particles and 110 µm copper particles. This impedance detection method provides a new technical support for the high-precision distinguishing measurement of metal debris. The sensor can not only be used for oil detection in the laboratory, but also can be made into portable oil detection device for machinery health monitoring.

Fatigue Analysis of Metallic Strips Flexible Pipe

2018 ◽  
Author(s):  
Guowei Sun ◽  
Peihua Han ◽  
Yuxin Xu ◽  
Yong Bai ◽  
Hamad Hameed
Keyword(s):  
Fatigue Life ◽  
Global Analysis ◽  
Element Model ◽  
Dynamic Responses ◽  
Flexible Pipe ◽  
Steel Strips ◽  
Counting Algorithms ◽  
Marine Engineering ◽  
Rainflow Counting ◽  
Specific Working

Metallic strips flexible pipe (MSFP) is widely regarded as an alternative for submarine pipelines. This paper presents a methodology for calculating the fatigue life of MSFP. Firstly, given a specific working condition of MSFP, the dynamic responses of MSFP are calculated through OrcaFlex. The obtained results from the global analysis are then implemented into a finite element model in ABAQUS to determine the stress-history curves of each steel strips layer. The estimated fatigue life is calculated by rainflow counting algorithms, S-N curve and Miner’s rule which are coded in MATLAB. Additional study about average stress correction is carried out, which might be useful for its marine engineering applications.

scholarly journals The Effect of Magnet-to-Coil Distance on the Performance Characteristics of EMATs

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5096
Author(s):  
Yutang Wu ◽  
Yunxin Wu
Keyword(s):  
Numerical Simulations ◽  
Conversion Efficiency ◽  
Performance Characteristics ◽  
Practical Application ◽  
Electromagnetic Acoustic Transducer ◽  
The Poor ◽  
Acoustic Transducer ◽  
Lift Off

The poor conversion efficiency and obvious lift-off effect of the electromagnetic acoustic transducer (EMAT) are commonly known to be problems for its practical application. For the purpose of enhancing the performance of EMATs, numerical simulations were performed in order to analyze the effect of various parameters. The results indicate that only the magnet-to-coil distance can effectively enhance the conversion efficiency and weaken the lift-off effect at the same time. When the magnet-to-coil distance is 2 mm, the lift-off effect will continue to be weakened as the magnet-to-coil distance increases, whereas the decrease of the lift-off effect is inconspicuous and the conversion efficiency starts to decline at this time. Therefore, to get the best performance of this specific EMAT, the suitable magnet-to-coil distance is 2 mm. The experiment effectively verifies the improvement of EMATs with a magnet-to-coil distance of 2 mm.

Microstructure, Texture and Inhibitors of the As-Cast and Hot Rolled Grain-Oriented Silicon Steel by Strip Casting

2016 ◽  
Vol 852 ◽  
pp. 101-104 ◽  
Author(s):  
Wen Qiang Liu ◽  
Cheng Shuai Lei ◽  
Han Mei Tang ◽  
Hong Yu Song ◽  
Hai Tao Liu
Keyword(s):  
Hot Rolling ◽  
Texture Evolution ◽  
Fiber Texture ◽  
Silicon Steel ◽  
Rolling Reduction ◽  
Recrystallization Annealing ◽  
Goss Texture ◽  
Steel Strips ◽  
Columnar Grains ◽  
Hot Rolled

The microstructure and texture evolution of the as-cast and hot rolled grain-oriented silicon steel strips was investigated, and the precipitation of the inhibitors of the hot rolled strips was clarified. The results showed that the microstructure of the as-cast strip was characterized by coarse columnar grains with strong {001}<0vw> fiber texture. The microstructure of hot rolled strips was composed of ferrite and pearlite and the microstructure was gradually refined with increasing hot rolling reduction. In the hot rolled strips, α and γ fiber textures were enhanced at the expense of initial {001}<0vw> fiber texture and Goss texture was generated in the surface and sub-surface layer with increasing hot rolling reduction. Besides, a great number of dispersed MnS particles with the size of 20-30nm were observed in the hot rolled strips. These MnS particles could act as the effective inhibitors during the second recrystallization annealing of the grain-oriented silicon steel.

Steerable Unidirectional Wave Emission From a Single Piezoelectric Transducer Using a Shape Memory Alloy Composite Metasurface

2020 ◽  
Author(s):  
Yihao Song ◽  
Yanfeng Shen
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Excitation Frequency ◽  
Element Model ◽  
Martensite Phase ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Unit Cell ◽  
Wave Radiation ◽  
Wave Emission

Abstract Structural Health Monitoring (SHM) and Nondestructive Evaluation (NDE) systems generally adopt piezoelectric transducers which emit omnidirectional wave fields. The achievement of directionality of guided wave generation will benefit the structural sensing purpose, which allows better detection and localization of the damage sites. In this study, a type of metamaterial ultrasonic radar is proposed for the steerable unidirectional wave manipulation. It contains a circular array of unit cells stuck in an aluminum plate which are delicately arranged in a circular fashion. Each unit cell is composed of a shape memory alloy substrate and a lead stub. The controllable bandgap of such metamaterial system can be achieved due to the stiffness change of nitinol between its martensite phase and austenite phase under a thermal load. This research starts with a Finite Element Model (FEM) of the unit cell to compute its frequency-wavenumber domain dispersion characteristics, demonstrating the adjustable bandgap feature. Then, numerical modeling of the metamaterial radar is performed by shifting the bandgap of one sector of the metasurface away from the excitation frequency. The modeling results demonstrate that the martensite phase metasurface area forms a bandgap region where guided wave energy cannot penetrate, while the bandgap of the austenite sector shifts away from the excitation frequency, opening up a transmission path for the ultrasonic waves. By rotating the austenite sector, the metamaterial structure can work like a wave emission radar, realizing of the steerable unidirectional wave radiation with a single transducer. Such an active metasurface possesses great application potential in future SHM and NDE systems.

Advanced Approaches to Diagnose and Treat the Chronic Autoimmune Disorders

2016 ◽  
pp. 70-98
Author(s):  
Tomasz Sołtysiński
Keyword(s):  
Immune System ◽  
Imaging Spectroscopy ◽  
Ultrasonic Waves ◽  
Optical Methods ◽  
Label Free ◽  
Experimental Systems ◽  
Cell Measurement ◽  
Living Organisms ◽  
On Chip ◽  
Molecular Components

Pathology and dynamics of particular cells and the molecular components of immune system is still challenging to be traced within living organisms. The techniques of molecular imaging (MI) are promising tools to monitor the immune system at work, to improve or allow personalized diagnostics and treatment, especially of the autoimmune diseases. In this study some possible targets for MI and biosensing are discussed. The personalized medicine, in addition to bioinformatics-based systemic approach, requires extensive research and novel high-throughput technologies like next generation of imaging, biosensing experimental systems based on microfluidics, nanotechnology, femtochemistry, superresolution (STED, STORM, PALM, SOFI, etc.), label-free imaging, spectroscopy (including TCSPC), MRI, multimodal optical methods, accoustic imaging through ultrasonic waves, nuclear medicine methods like SPECT and PET. Moreover, dedicated designs of modular Lab-on-Chip solutions are of high demand to perform multipurpose cell measurement and give a possibility to flexibly interact with sensed objects.

Numerical Study of Detection of Crack on Corroded Rough Surface Using EMAT-Generated Surface Wave

2021 ◽  
Author(s):  
Zhe Wang ◽  
Xuedong Chen ◽  
Zhichao Fan ◽  
Wei Chen ◽  
Jingwei Cheng ◽  
...  
Keyword(s):  
Surface Wave ◽  
Rough Surface ◽  
Numerical Study ◽  
Element Model ◽  
Center Frequency ◽  
Detection Accuracy ◽  
Electromagnetic Acoustic Transducer ◽  
Acoustic Surface Wave ◽  
Excitation Region ◽  
Acoustic Transducer

Abstract Electromagnetic acoustic transducer (EMAT) gradually becomes the main excitation method for surface wave, which is suitably used in periodic inspection or long-term monitoring of pressure equipment. However, the corroded surfaces appearing on the pressure pipes and vessels can cause an increase of background noise and remarkable attenuation of the echo wave, which restrict the improvement of detection accuracy of surface crack. In this paper, a finite element model of EMAT-Generated surface wave inspection for steel plate with rough surface is established based on the constitutive equation of ferromagnetic materials. Considering the Lorentz force and magnetostrictive effect, the influences of rough surface on energy conversion of multiple fields in the excitation and propagation process of electromagnetic acoustic surface wave are separately investigated. The surface wave responses of cracks characterized by rectangular groove on corroded rough surface have been analyzed further. The numerical results indicate that the rough surface of the excitation region below the transducer with a center frequency of 330 kHz has a slight effect on the surface wave energy, while the surface roughness of the propagation region attenuates echo signal of crack significantly. The reflection coefficients of echo signals can be utilized to quantitatively characterize the depth of crack on the corroded surface with roughness less than λ/15 (λ is wavelength of surface wave).

Pre-Optimization of Asymmetrical Underplatform Dampers

2016 ◽  
Author(s):  
Chiara Gastaldi ◽  
Muzio M. Gola
Keyword(s):  
Contact Surface ◽  
Contact Stiffness ◽  
Contact Point ◽  
A Priori ◽  
Element Model ◽  
Contact Forces ◽  
Friction Coefficients ◽  
Lift Off ◽  
Lower Limits ◽  
Underplatform Damper

The numerical coupled optimization of an underplatform damper is the exploration of its dynamics through a finite element model which includes both the damper and the blades. This is an effective approach if the initial damper mass and geometry have been previously selected in such a way that those parameter combinations leading to undesirable damper behavior (i.e. contact point lift-off, jamming, excessive contact forces) are ruled out a priori. This can be obtained through a pre-optimization where, after choosing the damper type the following main steps are followed: 1. ensure that damper jamming is avoided through an appropriate choice of platform angles, in function of the friction coefficients; 2. ensure that damper lift-off is avoided through an appropriate choice of the shape and position of the damper-platform flat contact surface and the position of the damper mass center; 3. set upper and lower limits to the value of damper-platform contact forces (as a multiple of the damper centrifugal force), the first being related to friction and wear problems, the second to the very existence of bilateral contacts; 4. check the model, and in particular the values of friction coefficients and contact stiffness, against experimental results. Once the above knowledge concerning the most desirable damper shape has been gathered an effective coupled-optimization can safely be performed. This is done by finding the most effective match between the damper size/mass and the bladed disk through a non-linear dynamic calculation (not examined in this paper). The outcome of both the pre-optimization and the coupled optimization are strongly dependent on the assumed values of friction coefficients, which depend on the contact surface type (then, different for the left and right side of the damper) and the contact pressure. The paper capitalizes on already developed tools, presented in previous ASME papers, such as the test rig developed by the AERMEC lab to draw the appropriate values of contact parameters, the numerical model representing the stand-alone dynamics of the damper between the platforms and the automatic random sampling tuning procedure. The purpose of the paper is to illustrate the procedure through the analysis of a family of rigid bar dampers with a curved-flat cross section.

scholarly journals Measuring system for magnetostriction of silicon steel sheet under AC excitation using optical methods

1998 ◽  
Vol 34 (4) ◽  
pp. 2072-2074 ◽  
Author(s):  
T. Nakase ◽  
M. Nakano ◽  
K. Fujiwara ◽  
N. Takahashi
Keyword(s):  
Steel Sheet ◽  
Silicon Steel ◽  
Measuring System ◽  
Optical Methods ◽  
Ac Excitation
Sign in / Sign up

Export Citation Format

Share Document