Applied Mechanics and Materials Vols. 217-219

Abstract: The formation of porosity in 40mmx200mmx100mm ductile cast iron test block under different conditions of mold dilation and graphite precipitation has been investigated based on The formation of porosity in 40mmx200mmx100mm ductile cast iron test block under different conditions of mold dilation and graphite precipitation has been investigated based on MAGMA software. The simulation results show that the variations of graphite precipitation have evident influence on the formation of porosity, while the variations of mold dilation have little influence on the formation of porosity in ductile cast iron. Because the graphite precipitation is a sensible factor for the formation of porosity, its exact value should be determined based on the metallographic analysis, the simulation results were in good agreement with the experimental results. Because the mold dilation is an insensible factor for the formation of porosity, it is commonly considered to be stable; however, the simulation result falls short of the experimental results when the mold is weak green sand.

Abstract: On the basis of previous work, the simulation condition of cold store was improved to reduce calculation error. The SIMPLE algorithm and Boussineq assumption were used and the turbulent intensity was also set. The numerical simulation results reflected that the temperature distribution was closer to the previous experimental results after using new method. The error between simulation values and experimental values was decreased. The simulation result showed that temperature of corner was highest in the cold store. The temperature change of the cold store in the cooling process could be better predicted by using modified simulation method and the accuracy of numerical simulation of cold store in the cooling process could also be validated.

Abstract: A method based on mechanical kinetics, Virtual Prototype technology and Finite Element Method (FEM) is proposed, aiming at the dynamic balance of planar linkage with elastic deformation. The method applies to the situation that the elastic deformation of the components can’t be neglected. Translate the key components to flexible bodies by FEM; Build the rigid-flexible multi-body dynamics model by dynamic analysis software, and synthetically optimize the dynamic balance of the model by using the comprehensive indicator which includes input torque, shaking force and moment as the objective function; Finally, according to the parameter result of the previous optimization, the component’s geometrical shape was designed in three-dimensional modeling software. Taking a kind of crank-slide mechanism as an example, it uses this method to optimize a crank-slide mechanism’s dynamic balance and to make the objective function value declined by about 9.2%. The mechanism’s vibration characteristic is improved, so the method is proved to be practical and effective.

Abstract: The proper choices of a process parameter design (PPD) decision problem are studied in a noisy environment of a grease position process in an electronic industry. The process responses consist of the mean of parts between failures on left and right processes. A multi-response surface optimization problem is then proposed to maximize these dual process responses. The conventional modified simplex method and its hybridizations of the stochastic operators from the hunting search and ant colony optimization methods are applied to determine the proper levels of controllable design parameters affecting the quality performances. A numerical example demonstrates the feasibility of applying the proposed model to the PPD problem via two iterative methods. Its advantages are also discussed. Numerical results demonstrate that the hybridization based on the hunting search method seems to be superior when compared. In this study, the mean of parts between failures is improved by 27.04%, approximately. All experimental data presented in this research have been normalized to disguise actual performance measures as raw data are considered to be confidential.

Abstract: The purpose of this study is to determine the optimal design parameters of the heat treatment process (HTP) in the context of the multi-response surface optimization. An aim is to improve quality characteristics in the HTP by simultaneously optimizing hardness, stain yield and roundness via pre-heat and heat chamber heaters, number of vacuum, gas fan speed in quenching chamber and partial gas pressure. Taguchi orthogonal design and desirability function approach are applied to form the path of steepest ascent. Influential parameters from the hunting search and ant colony optimization metaheuristics are integrated to seek the optimum. The results proved that the hybrid approach based on the hunting search optimization mechanism was successfully applied in the study. The confirmation tests based on the predicted optimal results were verified and carried out to show considerable improvement.

Abstract: Surface characteristics of the regular polygon contour parts and turning process,including tool movement characteristics,feed speed and feed acceleration, is analyzed with the harmonic analysis principle when cutting the parts. Using MATLAB to draw the displacement, velocity and acceleration variations chart of polygon workpiece turning.

Abstract: Particle packing model are always utilized to investigate and predict micro structure performance of material. On one hand, considering 3 classical packing methods, it’s found that random packing method for model of resin concrete is the most suitable. 3D Particle packing model on Matlab is realized through compiling programs, then converted into Ansys and study on porosity of it proves the correctness of the packing model. On the other hand, different from others’ applying Walraven J.C Equation with a quite limited applicability to getting slice, this paper proposes that slice directly from the 3D model is more accurate and scientific, which is also managed to realize on both Matlab and Ansys.

Abstract: The influence of friction on deformation behavior of copper rods during the continuous ECAP process (a modified C2S2 for the processing of rods and wires) was analyzed by using DEFORM-2D finite element method. The effect of friction on the stress and strain distribution, strain homogeneity and the torque-time curves was investigated. In the modified C2S2 process, the effective stress distributions are symmetrically concentrated on the shear plane, but there is an inadequate length of the plastic deformation zone. The effective strain shows a distorted fan shape in the shear deformation zone. As the friction factor increases the distorted fan shape tends to be normal and thinner, indicating that the bigger the friction factor, the more homogeneous the shear deformation. The effective strain is uniform across more than 70% thickness of the specimen. The assumed shear deformation is further divided into three stages, which can be explained by the torque-time curves.

Abstract: Because of product variety of small electronic products enterprises,Their equipment is in condition of half stop production, resulting in the waste of equipment and personnel. Canon cell production from mixed line production mode innovation out of a new way of production, applicable to the production equipment is not too big, need manual operation of the production. This paper tells small batch orders and the premise, split mixed line composed of Canon cell production to improve production efficiency, reduce the cost. It gives the mathematical model and the simulation results.

Abstract: Constructing accurate constitutive equation from the optimal material constants is the basis for finite element numerical simulation. To accurately describe the creep ageing behavior of 2A12 aluminum alloy, the present work is tentatively to construct an elastic-plastic constitutive model for simulation based on the ANSYS environment. A time hardening model including two stages of primary and steady-state is physically derived firstly, and then determined by electronic creep tensile tests. The material constants within the creep constitutive equations are obtained. Furthermore, to verify the feasibility of the material model, the ANSYS based numerical scheme is established to simulate the creep tensile process by using the proposed material model. Results show that the creep constitutive equation can better describe the deformation characteristics of materials, and the numerical simulations and experimental test points are in good agreement.