Scientia Iranica
Volume:30 Issue: 6, Nov-Dec 2023

Fast Fourier transform method is the standard method for the calculation of numerical Fourier transform and then the impedance of electrochemical systems. However, the presence of noise in the data results in a high error rate in calculating the numerical Fourier transform. Therefore, to reduce the error rate in noisy conditions, the solution order of the Fourier transform can be increased. In the present paper, the solution order for calculating the numerical Fourier transform in the presence of noise has been raised using a straight line, second and third-order polynomials; afterward, the impedance of series, parallel, and battery circuits is calculated. Additionally, the higher order solutions’ calculated impedance is compared to the acquired impedance in the FFT method in noisy conditions. We conclude that increasing the solution order of numerical Fourier transform from zero to one leads to good results, but further enhancement of solution order deteriorates the responses. Therefore, the linear method is the best way for calculating the numerical Fourier transform in the presence of noise.

The aim of this study was to investigate the vibration behavior of soft magnetoelastic plates mounted close to rectangular conductors conducting current. New relationships are derived for electromagnetic interaction forces with magnetoelastic plates by taking into consideration the general form of Maxwell's equations and Lorentz forces. By using von-Kámán strain-displacement relations and Hamilton's principle, we derive the nonlinear differential equations for the plate based on classical first-order shear deformation theory. It is investigated numerically how different parameters affect the resonance features of these plates by discretizing the nonlinear equations using the Galerkin method. It has been demonstrated that the intensity of the magnetic field and electric current has a profound effect on the vibration behavior of the plates. Through these effects, energy is lost in the plate, which, as a result, results in a decrease in oscillation amplitude over time.

Due to their lightweight, new classes of materials including aluminium-based Metal Matrix Composites (MMCs) have been popular in recent years in various industries including aircraft and automobiles. Because of its low cost and ease of availability, aluminium alloy (LM13) MMCs were developed using Rice husk ash (RHA) as reinforcement in this study rather than traditional reinforcement and composites were prepared using the stir casting technique. LM13-15wt.%RHA composite was chosen for the present machining study. The central composite design (CCD) with three input parameters at three levels based on the best outcomes was adopted for this experimental study. A mathematical model was developed to predict the machining responses of Material Removal Rate (MRR) and surface roughness. The most significant variables were evaluated using ANOVA. The main and interactive effects of the input variables on the predicted responses are determined. The experimental and predicted values are nearly identical, indicating that the developed models can accurately predict responses. The optimal value of the turning parameters was obtained from desirability analysis. The obtained desirability value for turning parameters is 0.863, and for output response, the value of desirability for surface roughness is 0.71663 and for MRR is 0.747491, and combined desirability is 0.731898