Papers by Keyword: Interpolation Method

Abstract: The article substantiates the method of identifying the mechanical characteristics of concrete of reinforced concrete beams based on the results of fire tests. The idea of the work is to improve the calculation approach to assessing the fire resistance of reinforced concrete beams by clarifying the mechanical characteristics of concrete during its heating under the conditions of exposure to the standard fire temperature regime. The proposed method of identifying the mechanical characteristics of concrete is based on the reproduction of temperature distributions in the cross-sections of reinforced concrete beams based on the results of point temperature measurements during fire tests and the application of equilibrium equations compiled using the deformation mathematical model of the stress-strain state. As a result of the obtained experimental data, the temperature distributions were reproduced using the proposed interpolation method. According to the obtained temperature distributions and the proposed mathematical apparatus, the coefficient of reduction in the concrete strength of reinforced concrete beams during fire tests was identified, the maximum deflection of two sample reinforced concrete beams was determined, and using a deformation model based on the use of equilibrium systems of internal layers in the cross section of reinforced concrete beams, the coefficient of reduction of strength of concrete under the condition of exposure to the standard fire temperature regime was specified.. The presented curves of the value of the coefficient of reduction of concrete strength according to the proposed method and according to the recommendations of Eurocode 2 indicate the presence of a deviation between these indicators. Therefore, the refined dependence of the coefficient of reduction of concrete strength for reinforced concrete crossbars will allow to significantly increase the accuracy of the calculation method of fire resistance assessment for structural elements of this type.

Abstract: This paper presents an interpolation-based method for multidimensional extrapolation. A series of interpolation formulations are proposed to extrapolate functions normal to the interface between two regions. Theoretical proofs and relevant analysis are also presented. The method developed maintains the characteristics of implicit interface. The interface inside every cell is treated smoothly by assuming that curvature is equal everywhere. The method developed and numerical results are verified by comparing to the results by PDE method and theoretical results. Numerical tests demonstrate that the method developed is first-order accuracy and also more efficient in numerical implementation and more accurate than PDE method.

Abstract: This paper presents a comprehensive virtual simulation model for CNC systems. The Virtual CNC (VRCNC) has a modular architecture and the special function. It can show movement process and the result, it can also show the effect of different movement mode, the displacement, velocity and acceleration of the process, the rationality of interpolation method and the motion control method. Additional CNC modules can easily be prototyped and integrated to the VRCNC by the user. Various application examples are presented which include building of physical dynamic control model, the prediction of the displacement, velocity and acceleration of the process, and the process of secant instead of curve. It can show closed loop drive dynamics. Detailed experimental verification is presented for each algorithm.

Abstract: With the development of computer technology, casting simulation plays an increasingly important role in foundry production. VOF (Volume of Fluid) method which tracks free surfaces is widely used in casting simulation because it is simple to solve and easy to achieve. However, in the last stage of mold filling process, the solution speed of VOF method is very slow because the space to fill becomes smaller. To solve this problem, interpolation formula is applied to the calculation of temperature field and an interpolation method to calculate the last part of temperature field in mold filling process is presented in this paper. The solution is to calculate temperature field of unfilled grids based on the temperature filed of filled grids at the last stage of filling process. Comparison between the results of interpolation method and theoretical calculation illustrates the rationality of the interpolation temperature field in this paper. Numerical simulations of actual castings indicate that the interpolation method can greatly improve the speed of getting temperature field under a certain accuracy. This paper has important implications to the calculation of numerical simulation in mold filling process.

Abstract: In the design and manufacturing process of the hydrodynamic coupling, the fluid pressure on the impeller is difficult to calculate when analyzing the strength of the impeller. We can use the one-way fluid-structure interaction analysis. When interpolate the pressure on the flow field and structural coordinate values, choosing reasonable interpolation method can reduce the amount of computation, improve accuracy, simplify product design and manufacturing process. This article is based on one-way fluid-structure interaction analysis. We compare the four interpolation method in MATLAB, conclude that the spline interpolation is better than others. It is the most suitable for practical applications, which can simplify the design of the manufacturing process of the hydrodynamic coupling.

Abstract: The atmospheric transmittance of infrared radiation is the important parameter on the studies of infrared radiation, the Computation of atmospheric transmittance is professional and complicated and it is inconvenient for the application of engineering and technology. In order to gained the atmospheric transmittance of infrared radiation rapidly when the height of infrared apparatus place and the down range distance between infrared apparatus and infrared object are changed, Lagranges two unknown quantities and three points interpolation is used to computer the interpolations of the atmospheric transmittance of infrared radiation by the MODTRAN software, then the available data of atmospheric transmittance are gained. The experimental results show the interpolation method is effective and valuable in engineering applation.

Abstract: Thunderstorm days are used to show the lightning frequency happened somewhere. Through comparative analysis on the thunderstorm days data of 66 weather stations in Jiangsu province and lightning data of ADTD lightning monitoring, it presents that the correlation coefficient r became the largest at 11 km range, and the longest distance of thunderstorm artificial observation is 11-14 km. According to the study of lightning activities in Jiangsu province to get the statistical fitting function curve equation by thunderstorm days and ground flash density data. Test the actual application effect of fitting equation by calculating the average relative error of fitting equation and standard equation, then make sure the actual thunderstorm days in Jiangsu province and the cloud to ground flash density formula is N_g=0.0224 T_d^1.48.

Abstract: The underwater vehicle is mainly made of ferromagnetic material, the sensor measured except magnetic field, besides magnetic field that the vehicle of the inherent hard magnetic and soft magnetic materials produce and vehicle magnetic fields produced in mechanical and electrical equipment. At the same time, the precision of the geomagnetic measurements will be affected by sensor manufacturing error and installation error factors. Therefore, how to extract the magnetic field from complex environment is a real time measurement of a difficult problem. In this paper, it is based on soft compensation. The magnetic survey experiment that underwater carrier rotates 360 degrees underwater has been done on this basis, and the effect of underwater carrier on cesium magnetometer in different heading is analyzed. The degaussing algorithm for own magnetic field of carrier is obtained and the real value of underwater magnetic field can be restored. It is the solid foundation of high precision underwater geomagnetic navigation and establishing the underwater geomagnetic map.

Abstract: Errors in measurement of temperature have a significant negative impact on the thermal conductivity measurement. This paper analyses the causes of temperature error and why a small temperature error could often cause a huge error in thermal conductivity instrument. Since traditional methods often involve complex circuits or formulas, here we introduce a convenient and efficient method to improve temperature measurement accuracy, which by effectively combination of the table consulting and a new simple interpolation method introduced in this paper. It is implemented in the LabVIEW environment and experimental results show the accuracy of the instrument has been greatly improved.

Abstract: With measuring instrument accuracy enhancement, it is to meet the requirements of the geomagnetic matching location, but the underwater vehicle is mainly made of ferromagnetic material, the sensor measured except magnetic field, besides magnetic field that the vehicle of the inherent hard magnetic and soft magnetic materials produce and vehicle magnetic fields produced in mechanical and electrical equipment. At the same time, the precision of the geomagnetic measurements will be affected by sensor manufacturing error and installation error factors. Therefore, how to extract the magnetic field from complex environment is a real time measurement of a difficult problem. This paper is based on the magnetic dipole magnetic field distribution theory to establish the vehicle of the magnetic field distribution mathematical model, and through the carrier of space and azimuth magnetic measurement get vehicle plane space magnetic figure. Through the related coefficient to deduce the best position of the magnetometer attaching on the vehicle to make magnetometer the smallest influence while sailing in.