Applied Mechanics and Materials Vols. 300-301

Abstract: Based to the design scheme of the typical high-speed railway cutting, the numerical model on the high-speed railway cutting settlement deformation under rebound effect is established with suitable geometric and mechanical parameters. Some calculation cases are designed to study the settlement deformation evaluation method of high-speed railway cutting under rebound effect. Through analyzing the settlement deformation data of different conditions, the optimal curvilinear regression method is determined, the reasonable dead load observation period is discussed, and a new settlement deformation evaluation method with the assessment coefficient is established. This study will provide some reference for the design and the settlement deformation evaluation of the high-speed railway cutting under rebound effect

Abstract: Strength and elongation are two important parameters for evaluating the durability property of needle felt which is now widely used for the air pollution control. It is necessary to measure them as reasonable as possible. The paper researches on the effect of sample size on the strength measurement of needle felt. The results show that sample width of 5cm and sample length of 20cm are suitable value for strength measurement of needle felt and sample length has a bigger effect on strength measurement of needle felt than sample width.

Abstract: The large numbers of bolt holes cut into truck frame side members act as joineries and points of attachments for various sub systems of the truck. While these bolt holes are unavoidable due to their primary functional importance, the near hole residual stress resulting from the type of hole cutting operation plays a significant role in deciding the fatigue performance of frame rail structures. If the residual stress is tensile in nature, this along with the surface roughness at the hole surface can lead to early initiation of fatigue cracks around bolt hole surface. In order to assess the extent of plastic deformation and resulting residual stresses in near hole areas of frame bolt holes cut using drilling, punching, laser cutting and water jet cutting processes, experimental investigation was carried out through microstructure analysis and X-ray diffraction measurements. Apart from this, an assessment of shot-peened hole surface was taken up to understand the effect of shot-peening on fatigue behavior of frame rail section with bolt holes. Also the test specimens extracted from frame rail sections were tested for comparing the fatigue life of specimens having bolt holes cut using different hole cutting operations.

Abstract: Uneven distribution of temperature is one of the important factors which influences heavy rail bending changes during the cooling process. Through the research of temperature field can reasonable analysis the heavy rail bending change rule, so it is necessary to study the temperature change rule during heavy rail cooling process. This paper adopts finite element analysis software ANSYS to set up three-dimensional models of U75V heavy rail and the cooling bed, and numerical simulate the cooling process. In which, it is studied the temperature changing rules and its distribution rules, emphatically analyzed temperature changing rule during the phase transition phase, and got the temperature changing rules and distribution rules in final cooling time. Especially, it is considered that the heavy rail placed on its side, the latent heat of phase transition and thermal radiation. This research can provide the theory basis and the advisory opinion on the formulation of cooling technological parameters and preflex regulations of the rail.

Abstract: In actual , there exist inevitably a lot of interference from neighbor machine and noise from surrondings in mechanical vibration signal measured by sensor ,which is disadvantageous for condition monitoring and fault diagnosis. In order to eliminate the axial vibration signal in the noise, using Wavelet packet denoising method in this article, Emulating experiment s were carried out under the MATLAB software ,original signals adopted vibration impulsion signal produced by vice position of faulty bear. Separation result s confirm this method successfully ext ract original source ,efficiently removes noise.

Abstract: In this paper, the crack tip stress field on a three-point bending specimen with a fatigue precracked crack under concentrated loads was analyzed using ABAQUS. The stress intensity factor obtained from simulation was compared with theoretical analysis results and they agreed well. It is found that the result presented using the extended finite element method is capable of providing a reference for further study of the stress intensity factor.

Abstract: P-SS algorithm for solving eigenvalue problem was obtained, based on the power method and the similar shrinkage method. This algorithm can be used to not only solve all eigenvalues of small system, but also partial eigenvalues of large finite element system. The calculation program of this algorithm is universal and practical. Compared with the existing methods, the error of P-SS method is very small, and it signify that the new method is feasible and convenient.

Abstract: A D2Q9 thermal lattice Boltzmann model is applied to investigate the flow in a differentially heated cavity. The paper is intended to analysis the physics of heat and mass transfer in a closure cavity filled with air. For three Rayleigh numbers Ra, the aspect ratio K are varied from 1 to 10. Results of validation indicate this algorithm is reliable and easy for implementation. It can be found that the circulation rate of heat driven flow get lower when the K get higher. Also, the Nusselt number Nu tends to be approximated to 1 when K is higher than a critical value, which is depended on the value of Ra.

Abstract: In case of constructions placed on subsoil, it is necessary to create a rigidity matrix for the element subsoil. That rigidity matrix should be then added up in respective positions with the rigidity matrix of an element. To clarify the proposed model of the subsoil, a method is derived for determination of vertical subsoil stress analysis under any shape of a slab construction by means of numerical integration and theory of isoparametric elements using the Jacobian transformation. This approach is rather original and represents the key contribution of this work in interaction solutions. Using the proposed approach, the method can be employed for any shape of a finite element.

Abstract: A linear aeroelastic continuum model for a variable-span wing is developed. Considering the fixed inboard part and the movable outboard part of the wing, a stepped Euler-Bernoulli beam with three jumped discontinuities in its spatial span is used for structural modeling. The dynamic analysis of stepped beam is introduced by a dimensionless form. The time-domain aerodynamic forces are calculated by a reduced-order unsteady vortex lattice model. Then the first-order state-space aeroelastic formulations are built by using the Galerkin method. The impact of the different wing configurations is of particular interest for understanding the fundamental aeroelastic behavior of variable-span wing. To clarify the implementation of the proposed method, a simple variable-span wing with the basic parameters of the Goland wing is studied, and numerical simulations are provided to demonstrate the flutter speeds and frequencies for different wing configurations.