Ultrasonic Position Measurement using Phased Array Microsensors with Resonant Frequency Variation

2007 ◽  
Author(s):  
K. Yamashita ◽  
K. Iwahashi ◽  
Y. Ohmura ◽  
M. Okuyama
Keyword(s):  
Resonant Frequency ◽  
Phased Array ◽  
Frequency Variation ◽  
Position Measurement

Energy Resource for a RFID System Based on Dynamic Features of Reddy-Levinson Beam

2020 ◽  
Author(s):  
Alireza Babaei ◽  
Johné Parker ◽  
Paria Moshaver
Keyword(s):  
Resonant Frequency ◽  
Shear Deformation ◽  
Displacement Field ◽  
Energy Harvester ◽  
Frequency Variation ◽  
Low Input ◽  
Piezoelectric Energy ◽  
Rfid System ◽  
Proposed Model ◽  
Thick Beam

Abstract Understanding the effect of design parameters on resonant frequency variation is a critically important aspect of piezoelectric energy harvester device design. As a first step in more accurately investigating the performance of a fixture designed for targeted RFID tag communication that also utilizes an energy harvesting application, this paper analyzes the variations in resonant frequency of a higher-order beam based on Reddy-Levinson theory (RLBT) under rotation effects. A long-term goal of this research is to implement an effective energy harvester on the RFID system. Part of the experimental RFID test fixture can be modeled as a beam (or beam element); thus, understanding the resonance frequency variations due to shear deformation and rotation effects is an important first step in obtaining information about the efficacy of the fixture in serving as an energy harvester. Investigating the performance of a beam also provides valuable information about the maximum power, frequency bandwidth, and tuning ability of the device that can be expected from an analogous energy harvester. For the first time, the resonant frequency variation of a rotating thick beam is investigated. Specifically, RLBT is used to verify the effects of shear deformation upon resonant frequency, and a coupled displacement field is utilized to enable tuning the potential piezoelectric energy harvester to low-input excitations by means of constraining translational and rotational movements of the system based on a linear constraint equation. Navier’s method as an analytical-numerical method is adopted to discretize the continuous system and to find resonant frequencies, respectively. Results reveal the significance of beam thickness and rotation effects of the proposed model for the purpose of minimizing energy usage. Current results are compared and verified numerically with available benchmarks to confirm a satisfactory level of accuracy. The proposed model, which is based on a coupled displacement field, can also be used to design other piezoelectric electro-mechanical-systems; e.g., vibration isolators, and vibration controllers. In other words, in an energy-scavenging system, a fundamental understanding of parameters affecting the resonant frequency can be accomplished through the presented analysis. The proposed model highlights the fact that, by adopting a proper speed factor, tuning the piezoelectric energy harvester to low-input excitations is possible. Additionally, it is observed that the rotation effect on the resonant frequency is more severe than effects of slenderness ratio. Finally, in this paper an improved model is proposed to capture the shear deformation effect, particularly for thick-beam energy harvesters, with the capability of tuning to low-input excitations.

scholarly journals Model for Wireless Magnetoelastic Strain Sensors

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3557
Author(s):  
Eduardo S. Bastos ◽  
Cristina Bormio-Nunes ◽  
Thomas G. R. Clarke ◽  
Frank P. Missell
Keyword(s):  
Magnetic Field ◽  
Resonant Frequency ◽  
Strain Sensor ◽  
Strain Curve ◽  
Strain Sensors ◽  
Frequency Variation ◽  
Marine Riser ◽  
Magnetoelastic Properties ◽  
Materials Used ◽  
Strain Dependent

This paper describes a magnetoelastic strain sensor based on the ∆E effect and discusses some materials used in its construction. A polycrystalline Fe–Al–B alloy with good quality magnetoelastic properties was used as the transducer and glued to the test object, either brass plates or rods of SAE 1010 steel. The strain-dependent magnetic field of the transducer changes the operating point of the resonator, a strip of field-annealed Metglas 2826MB3, resulting in a modification of its resonant frequency. A model was developed to simulate the strain-dependent magnetic field acting on the resonator and thus to calculate curves of resonant frequency vs. deformation. With the help of this model, differences in the shape of the frequency vs. strain curve can be understood. For a sensor with resonant frequency of 60.5 kHz glued to a rod of SAE 1010 steel, a total resonant frequency variation ∆f ~7 kHz was observed for a deformation of 1100 ppm. The geometry of this sensor is especially favorable for the remote monitoring of a steel surface, such as the wires of the tensile armor of a marine riser.

Effects of Chemical Components and Manufacturing Process of Cast Iron Brake Disc on its Resonant Frequency Variation

2009 ◽  
Vol 2 (2) ◽  
pp. 19-24 ◽  
Author(s):  
Jae Young Lee ◽  
Hyun Dal Park ◽  
Seong Jin Kim ◽  
Jae Min Han ◽  
Yoon Cheol Kim ◽  
...  
Keyword(s):  
Cast Iron ◽  
Resonant Frequency ◽  
Manufacturing Process ◽  
Chemical Components ◽  
Frequency Variation ◽  
Brake Disc
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