Applied Mechanics and Materials Vols. 444-445

Abstract: In recent years, the cases that bridges under the action of debris flow been damaged have increased year by year. In this paper, the dynamic response of the double-column pier under the action of the debris flow are studied. Using the finite element method, considering the action of the upper structures dead load, the analysis of the changes about the displacement and stress of the pier bottom was conducted, as well as the deformation and stress changes in pile foundation.

Abstract: Spontaneous combustion is a complicated process and its control function is a partial differential equation (PDE) of heat conduction. To solve the problem of spontaneous combustion, we should specify some parameters first, such as the heat source, thermal conductivity, convective heat transfer coefficient, and so on. Some parameters can be got easily and accurately, but some are not. So there could be a great gap between the result of numerical simulation and the result of experiment. For this inverse problem, we can estimate these parameters with the MCMC (Markov Chain Monte Carlo) method. Then, we could get more accuracy and reliable numerical result.

Abstract: The evaluation of stability and reliability of support system for tunnel weak surrounding rock are difficult issues of concern in rock and soil engineering. Aiming at the problem of parameter design and reliability evaluation of tunnel weak surrounding rock and bolt-shotcrete support system, the deformation, failure mechanism and physical mechanical properties of weak surrounding rock are analyzed as well as the mechanism of bolt-shotcrete support in soft rock is studied. And the reliability analysis equation of bolt-shotcrete support in two kinds of weak surrounding rock (nearly horizontal layered mechanics medium and continuum mechanics medium) is established. The quantitative soft rock supporting theory is introduced into the reliability analysis equation. The calculation formula of two important design parameters of anchoring force and bolt spacing in bolt-shotcrete support is established. Finally an engineering example is adopted to prove the rationality of the calculation results. Therefor this paper provides theoretical basis and design method for supporting structure design and reliability evaluation of tunnel weak surrounding rock.

Abstract: The study about the impact of implant denture on getting stuck between the teeth is rarely reported. Computational modeling and simulation was performed in this study in order to investigate the effect of planting denture on interdental food impaction. Four groups of experiment were designed; Simplified teeth models were established and meshed; loads were applied to the models and boundary conditions were constrained in the state of teeth chewing. Finite element method was employed to analyze the deformation of teeth and impacted object. When the force exerting on the impacted object is in the range of 0-5.5N, the distance between denture and tooth after planting denture is less than that between the normal teeth. The deformation is the minimum when the denture is lower than tooth. When the force exerting on the impacted object is in the range of 0-5.5N, interdental food impaction is easier to occur after planting denture, and Interdental food impaction may be more likely prevented when denture is lower than tooth.

Abstract: The single-phase flow and heat transfer for multi-layer rectangle micro-channel heat sink are numerically simulated. During the simulation, Finite Volume Method (FVM) was used to solve Computational Fluid Dynamics (CFD) problem. First order upwind scheme was used to discrete control equations, and semi-implicit method for pressure-linked equations was used to solve discretization equations. The maximum temperature difference is 76.2362 °C, and the total thermal resistance is 0.4765 °C/W, which agrees well with the result of analysis result 0.5145 °C/W. The corresponding pressure drop is about 54.1360 N/m².

Abstract: In this paper, a 3-dimension finite element with dummy nodes for calculating and outputting the stress energy release (SERR) at the crack tip was built up based on virtual crack closure technique (VCCT), it is presented to demonstrate the virtual crack closure technique has high accuracy and good feasibility. The calculation results curve and the analytical solution curve are in good agreement. The results show that the proposed interface elements can be used to calculate to get accurate results by finite element analysis. It can give us some new ideas for Hydraulic structure crack research.

Abstract: It is well known that traditional finite element (FEM) is an efficient method in solving engineering problems. However, when solving the acoustic problems in medium frequency, FEM suffers from the so-called pollution effect, which is directly related to the dispersion. In this paper, meshless method based on radial basis function (RBF) is introduced to solve the acoustic problem, which shows that the dispersion can be greatly reduced, thus it is very suitable for the solution of mid-frequency acoustic problem. In addition, an algorithm is presented to treat the boundary condition, which improves the performance of the meshless method.

Abstract: Soil is one of the important mediators in the agricultural production and its particle is a discontinuous, heterogeneity and nonlinear natural geological substance. It is difficult to analyze the soil cutting process by using traditional methods. According to the discrete nature of the agricultural soils, discrete element method based on the discontinuity assumptions can be an alternative to analyze the changes under external forces in the soil cutting process. This article describes the basic principles, its applications and its prospects of the discrete element method, especially in the field of soil cutting.

Abstract: Molecular dynamics simulation Refers to multi-body system consisting of atomicnucleusand electrons, solving Newton's equations of motion. Each nucleus is seen as a movement under the combined action of all other nucleus and electrons. By analyzing the force of every particle in the system, classical or quantum mechanical method is used to solve the position and velocity of individual particles in the system for a certain time, and to determine the state of motion of the particle, then to calculate the structure and properties of the system [1]. This paper describes the basic concepts and methods of molecular dynamics which are comprised of inter-atomic potential function like pair potential and multi-body potentials, time integration algorithm and so and.

Abstract: Analyzed the forces acting on the pulp in the refining zone of a high-consistency conical pulp refiner. A hydromechanics model for which presenting the flow of pulp along the plate has been derived through the calculation of the forces, which was composed two parts, since flat refining zone and conical refining zone formed the conical refiner.