Advanced Materials Research Vols. 557-559

Abstract: This article analyzes characters of automotive back light holders. It simulates the deep drawn forming process to optimize blanks by the software Dynaform which is used for analyzing plat materials’ in three dimensions- formation. It analyzes the formed result, comparing with the graph FLD and then modifies the local surfaces, which achieves the aim of optimizing process formed surface. Then we get the reasonable deep drawn surface of the die. Finally, the eligible products are produced.

Abstract: 3D modeling, virtual assembly and motion simulation of an up-open fan gate mine skip were completed with Pro/Engineer software. During virtual design, faults of a mine skip such as static and dynamic interference can be found out prior to be made, which is helpful to optimize it. Furthermore, it is effective to shorten design period of mine skip and save development cost and improve design quality.

Abstract: When hyper-static shaft was turned, its deformation mechanism was studied. Its finite element format was established when it was supported by the top. Considering the randomness of cutting force, elastic modulus, its length and its diameter, its probability finite element format was established. Moreover, its probability sample finite element model was established, and the effect of cutting force, elastic modulus, its length and its diameter to its maximum deflection was obtained. The study provides the method and theoretical basis for the analysis of the hyper-static.

Abstract: In this paper, elastic modulus of core cell in x direction was built. Equivalent tensile/compressive modulus of core materials in y direction and equivalent Poisson ratio of core materials in yox plane were also built.

Abstract: Simulation and study on Texaco gasification of semi-cokes prepared by DG coal pyrolysis process has been carried out by using Aspen Plus. The possibility that pyrolytic semi-cokes is used as the raw materials is discussed. Sensitivity study runs are performed to analyze the effects of oxygen-to-char mass ratio, mass percentage of char in char water slurry and gasification pressure on the gasification process. Simulations indicate that molar percent content of effective components (CO+H2) reaches as high as 67.94% under operational conditions which oxygen-to-char mass ratio is 0.75; char water slurry concentration is 62.5% and gasification pressure is 4.0MPa. So semi-cokes made by DG coal pyrolysis process is the excellent raw materials for gasification. Sensitivity analysis show that oxygen-to-char mass ratio and mass percentage of char in char water slurry are the main factors that affect the gasification process; gasification pressure has little effect on the results of char gasification.

Abstract: This paper discusses the study of the multimode evolution of microfiber taper and its potential application of micromixer in the lab-on-a-chip. By using numerical simulation, multimode interference effects are demonstrated in the taper transition of a micro-nano fiber. Due to the leaked optical energy gasifies the solution surrounding the taper and produces air bubbles, the laminar flow effect is destroyed with the help of disturbance of air bubble and two solutions are mixed quickly. Therefore, it will be used in microfluidic platform for chemical analysis & testing, chemical synthesis and environmental monitoring.

Abstract: Direct internal reforming solid oxide fuel cell (DIR-SOFC) is directly fueled with hydrocarbons and converts the chemical energy of the fuel directly into electrical energy. Particle swarm optimization (PSO) with adaptive inertia weights has global search ability and faster convergence rate. Wavelet network (WN) combines the advantage of multi-resolution approximation (MRA) of the wavelet decomposition and the capability of neural networks in learning from nonlinear process. The DIR-SOFC is considered a complicated nonlinear multi-input and multi-output (MIMO) system which contains coupling parameters. A method combines the WN with PSO algorithm is applied to establish the model of DIR-SOFC, avoiding the consideration of the complex process inside the cell. The simulation results show that the obtained dynamic model can accurately simulate the dynamics of the DIR-SOFC.

Abstract: A new computational mass transfer model is proposed for simulating the chemical absorption process with heat effect by solving the average fluctuating mass flux in turbulent mass conservation equation and the average fluctuating heat flux in turbulent heat conservation equation, so that the concentration profile and the temperature profile of column can be obtained. The feather of the proposed model is to abandon the conventional way of introducing the unknown turbulent mass transfer diffusivity D_t and the turbulent thermal diffusivity α_t in the mass and heat conservation equations. By using the proposed model, the simulated results of CO₂ absorption by aqueous monoethanolamine (MEA) solution in an industrial scale column is presented, including MEA concentration, CO₂ loading and liquid phase temperature. The simulations are in agreement with the published experiment data.

Abstract: Based on the probability distribution theory of rock micro-unit strength and taking the Mohr-Coulomb damage criterion as the distribution variable, the theoretical equations for the evolution of damage variables and the statistical constitutive model of rock damage in triaxis test were established. The arbitrary triaxis experimental data w ere used to calculate the parameters in the model by using curve fitting method and extreme value method. The calculated results of the model agree well with the experimental data. This constructive model can reflect effectively the deformation characteristics of rocks under loads and the constructive relation between elastic strain and stress of rock damage.

Abstract: It is important to make sure the stress distribution in the media under high pressure water jet as to improve jets utilities. A numerical analyzing model of stress distribution about interaction of high pressure water jets impinging solid material is established according to fluid-structure interaction theory. Standard k-ε equations model and controlled volume method for the water jets, and elastic orthotropic continuum and finite element method for the solid are adopted. The stress distributions in the fluid field and inside solid material with different water jetting velocities were computed using the model and method. Numerical results show that the stress distributes obviously on the part solid material under water jets impingement. The impinging area is subjected to compression stress, and the maximum tensile stress is located on impacting surface and the maximum shear stress being under impacting center about half nozzle diameter away. It concludes that by controlling the jet velocity and distance, jet cutting, breaking, decoating, surface processing efficiencies could be improved.