Papers by Keyword: Fourier Series

Abstract: The article proposes a methodology for calculating CLT panels as composite beams. This approach allows for the analysis of panels with any number of layers. It is shown that, unlike existing approaches, the behavior of the panel is considered in two directions, rather than as a beam system. Initially, the stiffness characteristics of the panel are determined in each direction, taking shear into account. Then, the slab is analyzed as an orthotropic plate with different stiffness characteristics in mutually perpendicular directions. This calculation is performed either as an orthotropic solid plate or as a cross-laminated beam system. To determine the stiffness characteristics in each direction while considering the shear of the cross-layer boards, the theory of composite beams is used. Taking into account the boundary conditions, the system of differential equations is reduced to a system of algebraic equations by expanding the unknowns and external load in Fourier series.

Abstract: The method of calculating the shells of revolution for an asymmetric load using a semi-analytic finite element method is considered. An example is given of calculating a corrugated cylindrical tank for wind load. Comparison of meridional and annular forces is performed for a smooth and corrugated shell of identical dimensions.

Abstract: The submitted paper is focused on the design of Tuned Mass Damper in order to reduce excessive level of vibration. This device is designed to be active at the first natural frequency of the structure. Subsequently, the efficiency of the new dynamic system (structure-TMD) is verified for several types of time-dependent loads, which express swaying vandal, jumping vandal and moving pedestrian.

Abstract: The present article describes the analysis of electromagnetic field in an induction MHD-stirrer for liquid metals with the account of transverse di-mensions of the inductor and bath with melt. The parameters of the equivalent circuit of a MHD-stirrer and its electromagnetic characteristics have been defined.

Abstract: The presented contribution deals with steady state analysis of a two-phase asynchronousmotor, which is supplied by an IGBT transistors half- bridge connected inverter. The inverter outputvoltage is controlled by a SPWM of the input DC voltage. The complex Fourier series analysis of theinverter output voltage was made, to obtain a spectrum of the harmonic supply voltage. The differentvoltage harmonics was applied to the two-phase induction machine model to obtain electromagnetictorque and supply current waveform for various operation states.

Abstract: The present article describes the analysis of electromagnetic field carried out by an analytical method in the system inductor–bath with melt (liquid metal) taking into account different winding characteristics of the inductor. It also defines integral and differential characteristics of the system for the most widespread windings of an MHD-stirrer.

Abstract: The article deals with the numerical-analytical method of solving problems in the theory of elasticity of inhomogeneous bodies in terms of displacements for a circular cylinder. We consider two-and three-dimensional problems. After separation of variables, the problem is reduced to the numerical solution of the system of differential equations of the first order.

Abstract: In this paper the Halbach array with different segments per pole are modeled. The dimensions of magnets among segments are different with different magnetization direction. The unified harmonic model for the magnetic flux density distribution of the Halbach array with different segments per pole is derived by using Fourier series and magnetic scalar potential. Then the Halbach array with different segments per pole can be analytically analyzed and compared by the unified harmonic model.

Abstract: In order to reduce error of the wheel run-out detection system, a harmonic-analysis-based detection method was proposed to enhance the precision of online detection. The moving average filtering method was used for digital filtering between the axial and radial run-out errors so that to decrease the effect of outside noise on the measured data. Practical application shows that this system works stably and reliably on the wheel detection line and it realizes 100% online detection on the axial and radial run-out of work pieces, with the measurement error lower than 0.1mm.

Abstract: The purpose of power load forecasting is to provide the development status and level of the region's future load, providing the basis for the electric power production department and management department to make production and development plans. This paper puts forward the grey prediction model modified by Fourier series residual. First of all, the moving average method is used to preprocess the original data and weaken the burr of the original data. Secondly, the GM (1, 1) is used to estimate the load of the selected sample area. On this basis, use the Fourier series to revise the residual error of the grey forecasting model, making the model fitting of historical data as much as possible. The example analysis results show that the grey prediction model modified by Fourier series residual has the higher prediction accuracy compared with the general GM (1,1), proving the validity of the model.