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In this study, a planar printed circuit board (PCB) coil with FR4 substrate was designed and simulated using the finite element method, and the results were analyzed in the frequency domain. This coil can be used in wireless power transfer (WPT) as a transmitter or receiver, eliminating wires. It can also be used as the receiver in radio frequency energy‐harvesting (RF‐EH) systems by optimizing the planar PCB coil to convert radio‐wave energy into electricity, and it can be employed as an excitation (transmitter) or receiver coil in nuclear magnetic resonance (NMR) spectroscopy. This PCB coil can replace the conventional coil, yielding a reduced occupied volume, a fine‐tuned design, reduced weight, and increased efficiency. Based on the calculated gain, power, and electromagnetic and electric field results, this planar PCB coil can be implemented in WPT, NMR spectroscopy, and RF‐EH devices with minor changes. In applications such as NMR spectroscopy, it can be used as a transceiver planar PCB coil. In this design, at frequencies of 915 MHz and 40 MHz with 5 mm between coils, we received powers of 287.3 μW and 480 μW, respectively, which are suitable for an NMR coil or RF‐EH system. [ABSTRACT FROM AUTHOR]

This paper uses the vibration-based damage detection method for structural health monitoring of a Railway Bridge. Hence, the bridge had been exactly modelled in finite element analysis software. Due to the elastomeric bridge bearing, direct calculating of the natural frequencies and extracting the mode shapes of the bridge is not suitable and effective. Therefore, a time-dependent transient analysis of the train movement on the bridge is done and then the vibrations of all truss cells during the train crossing period were extracted. Afterwards, the relevant data is transformed, which represents the natural frequencies of the bridge vibration and their amplitude at each point. In the following, the mode shapes of vibration and the distribution of vibration energy are calculated. Applying any artificial damages in the model, occurring changes in the natural frequencies, mode shapes, and the vibration energies of the modes, are examined. Consequently, detecting and locating damages in the structure has been done with acceptable accuracy. Finally, for validation of the results, an accelerometer is installed on the bridge truss in the middle part of the bridge to extract the acceleration of bridge vibration at the train crossing time interval. In the end, the results are compared and presented. [ABSTRACT FROM AUTHOR]

This study includes the design procedure of a novel three-channel switch based on solid–solid phononic crystals. This elastic switch is externally controlled by the magnetic field. Proposed 1 × 3 switch is designed using Young's modulus variations (ΔE effect) of magnetostrictive materials due to change in the magnetic field intensity. The change in the elastic constant shifts the defect mode frequency position. A fundamental phenomenon in this switch is the major frequency shift, which is equal to 100 kHz for Terfenol-D Young's modulus reduction of 18%. It should be noted that this frequency shift occurs in presented phononic structure with a lattice constant equals to 500 μm. The major frequency shift is due to Terfenol-D high sensitivity to the magnetic field and using the hollow cylinders in output waveguides of structure. The elastic switch simulation is accomplished by finite element method. The crosstalk worst case in the proposed switch is −17 dB, which shows the device suitable performance. [ABSTRACT FROM AUTHOR]