Papers by Keyword: Boundary Condition

Abstract: By choosing deferent initial approximation solutions and deferent linear operators, the nonlinear equation of the jamming transition problem (JTP), which is based on the Lorentz system, in traffic flow is discussed. The approximation solutions of the JTP are obtained using the homotopy analysis method (HAM). The method of choosing the linear operators and the initial approximation solutions, the corresponding residual errors and the influence of the boundary condition to the solution are studied respectively. By comparing the present results with the previous related studies, the conclusion is drawn that the HAM is superior to the differential transform method. The correctness of the theoretical analysis is confirmed by numerical simulation and the analysis of the residual errors.

Abstract: Temperature and humidity of the pavement affected the performance of the pavement structure as the key factor. In this paper, we used the classic migration theory of temperature and humidity, and considered the actual characteristics of the asphalt pavement structure，established a temperature and humidity coupled equations for the asphalt pavement and got the calculation model by discretization，determined the boundary conditions and calculation parameters。Compared the calculation results with the actual results, we found that the model has high accuracy，it was able to meet the requirement of the predictive analysis about internal temperature and humidity of asphalt pavement in the work of researching and designing.

Abstract: Main aim of our recent research activity is the theoretical and experimental investigation of hard turning of AISI H13 (52 HRC) hot work tool steel. Chip removal processes are of essential importance in modern manufacturing technology. The demand for higher accuracy, better surface roughness, more economical production, and miniaturization are constantly growing. This determines continuous research and development of cutting processes under special circumstances. Numerical simulation plays an important role in evaluating of the cutting processes, and in prediction of forces, chip formation, distribution of strain, strain rate, stresses, and temperature. Cutting experiments with varying feed rate and cutting speed were carried out to determine their effect on surface components of resultant force. 3D finite element model was proposed to simulate the chip removal process during turning of workpiece material AISI H13 (52 HRC). This paper gives a summary about the comparison of theoretical and experimental results. It was found that boundary conditions, such as finite element size, mesh density, material separation method has significant influence on chip morphology and value of cutting force, too.

Abstract: The stress intensity factor and the T-stress describing the near-crack-tip fields for selected specimen shapes of a test geometry based on wedge splitting and three point bending tests with several variants of boundary conditions are computed using finite element software ANSYS. The test configuration in question is expected to be a convenient alternative to classical fracture tests (especially the tensile ones) for investigation of the quasi-brittle fracture of building materials, when low constraint is requested. These specimens are investigated within the framework of two-parameter fracture mechanics; near-crack-tip stress field parameters are determined and compared with those of the wedge splitting test due to their shape similarity. The sensitivity of the values of these parameters to the boundary conditions is also shown. Suitable choice of the shape of the specimens is discussed.

Abstract: By means of ANSYS, piston finite element model is constructed to attain transient numerical simulation and explore the characteristics of surface temperature. On the basis of experimental design, the correlation is analyzed between major boundary conditions and temperature of feature points, thus revealing the corresponding correlation of quantity. Transient calculation method is proved to be scientific and paves way to defining boundary conditions. And furthermore there forms a theoretical foundation for positioning test point in piston temperature field.

Abstract: A refined theory of transversely isotropic beam posting inside Winkler foundation is derived without ad hoc assumptions. Based on elasticity theory, the displacement field and stress states of isotropic body are studied. From boundary conditions, the refined theory of transversely isotropic beam posting inside Winkler foundation is given. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory.

Abstract: In this work a classical structural element inclined beam-column has been analyzed for two boundary conditions by applying a semi-analytical numerical technique differential transform method (DTM).Eigenvalues related to critical load and length, and deflection curves are presented for pinned-pinned and clamped-pinned end condition cases.

Abstract: The tool feed system main drive shaft of CNC spiral bevel gear milling machine is researched, and the vibration form of the drive shaft is confirmed.The main drive shaft is simplified using the lumped parameter method, the lumped mass model and the force model were been obtained. When bending vibrating, the natural frequency of the main drive shaft is calculated using the transfer matrix method. In order to verify the correctness of the calculations, the vibration of the main drive shaft is simulated by using ANSYS. This paper also designs the vibration control system for the main drive shaft, and analyzes influence factors which affects the vibration of the main drive shaft.

Abstract: Starting from the basic theory, to deduce the balance equations of the rod under the vertical and horizontal loads. Concerning the boundary problem, to analyze of this most general conditions, that is, the elastic rod ends are fixed on the elastic supports, thus to summary the common simplified boundary conditions.

Abstract: In order to reveal the vibration characteristics of the inflatable tubes of ETFE foils, the modal analysis was carried out for a 2.3m long inflatable tube of ETFE Foils. The equilibrium shape of the inflatable tubes was obtained from the static calculation with geometric nonlinearity. Modes of the inflatable tubes were achieved by the Lanczos method. The effect of boundary conditions, the inflatable pressure, the elastic modulus and air added mass on the vibration characteristics was analyzed. Analysis shows that the elastic modulus and air added mass have significant effect on the natural frequencies of the cantilever inflatable tubes. First frequency of the inflatable cantilever tube is less than the inflatable tube without constrains. Inner pressure has a slight effect on deformation modes with beam bending characteristics. The numerical method based on ABAQUS finite element analysis is reliable according to a comparison between test and simulation results.