• Transactions of Materials Processing
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• v.10 no.5
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• pp.373-382
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• 2001

Die design by computer simulation has some advantages compared with the conventional method which has performed by designer's experiences and trials and errors. The die filling and solidification process of thixoforming process were simulated by MAGMAsoft/thixo module. Furthermore, the die design for thixoforming was performed with the various geometry shape. The effect of designed gate dimension on filling phenomenon was estimated by filling simulation. The calculated results was compared with experimental data. The free surface phenomenon obtained by experiment have good agreement with computer simulation results. The solidification effect much as prosity and shrinkage for designed semi-solid forging die had been predicted by computer simulation. The designed die for semi-solid forging had been applied to produce of the frame part which is used to airconditious system.

• Journal of Powder Materials
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• v.9 no.4
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• pp.245-250
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• 2002

In this paper we presented numerical method for the simulation of powder injection molding filling process, which is one of the key processes in powder injection molding. Rheological properties of powder binder mixture such as slip phenomena and yield stress were introduced into the numerical analysis model of powder injection molding filling simulation. Numerical model can be classified into two types. One is 2.5D model which can be introduced to a arbitrary thin geometry and the other is full 3D model which can be applied to a general 3D shape. For 2.5D model we showed the validity of our CAE system with several verification examples. Finally we suggested flow analysis model for 3D powder injection molding filling simulation.

• Geomechanics and Engineering
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• v.22 no.6
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• pp.541-552
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• 2020

With the increasing tension of current coal resources and the increasing depth of coal mining, the gob-side entry retaining technology has become a preferred coal mining method in underground coal mines. Among them, the technology of the gob-side entry retaining with the high-water filling material can not only improve the recovery rate of coal resources, but also reduce the amount of roadway excavation. In this paper, based on the characteristics of the high-water filling material, the technological process of gob-side entry retaining with the high-water filling material is introduced. The early and late stress states of the filling body formed by the high-water filling materials are analyzed and studied. Taking the 8th floor No.3 working face of Xin'an coal mine as engineering background, the stress and displacement of surrounding rock of roadway with different filling body width are analyzed through the FLAC^3D numerical simulation software. As the filling body width increases, the supporting ability of the filling body increases and the deformation of the surrounding rock decreases. According to the theoretical calculation and numerical simulation of the filling body width, the filling body width is finally determined to be 3.5m. Through the field observation, the deformation of the surrounding rock of the roadway is within the reasonable range. It is concluded that the gob-side entry retaining with the high-water filling material can control the deformation of the surrounding rock, which provides a reference for gob-side entry retaining technology with similar geological conditions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.43-46
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• 2005

Micro molding technology is a promising mass production technology for polymer based microstructures. Mass production technologies such as the micro injection/compression molding, hot embossing, and micro reaction molding are already in use. In the present study, we have developed a numerical analysis system to simulate three-dimensional non-isothermal cavity filling for hot embossing, with a special emphasis on the free surface capturing. Precise free surface capturing has been successfully accomplished with the level set method, which is solved by means of the Runge-Kutta discontinuous Galerkin (RKDG) method. The RKDG method turns out to be excellent from the viewpoint of both numerical stability and accuracy of volume conservation. The Stokes equations are solved by the stabilized finite element method using the equal order tri-linear interpolation function. To prevent possible numerical oscillation in temperature Held we employ the streamline upwind Petrov-Galerkin (SUPG) method. With the developed code we investigated the detailed change of free surface shape in time during the mold filling. In the filling simulation of a simple rectangular cavity with repeating protruded parts, we find out that filling patterns are significantly influenced by the geometric characteristics such as the thickness of base plate and the aspect ratio and pitch of repeating microstructures. The numerical analysis system enables us to understand the basic flow and material deformation taking place during the cavity filling stage in microstructure fabrications.

• Geomechanics and Engineering
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• v.36 no.1
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• pp.27-37
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• 2024

The roof-filling body system stability plays a key role in gob-side entry retained (GER). Taking the GER of the 1103 belt transportation roadway in Heilong Coal Mine as engineering background, stability analysis of roof-filling body system was conducted based on the cusp catastrophe theory. Theoretical results showed that the current design parameters of 1103 belt transportation roadway could ensure the roof-filling body system stable during the resistance-increasing support stage of the filling body and the stable support stage of the filling body. Moreover, a verified global numerical model in FLAC3D was established to analyze the failure characteristics including surrounding rock deformation, stress distribution, and plastic zone. Numerical simulation indicated that the width-height ratio of the filling body had a great influence on the stability of the roof-filling body system. When the width-height ratio was greater than 0.62, with the decrease of the width-height ratio, the peak stress of the filling body gradually decreased; when the width-height ratio was greater than 0.92, as the distance to the roadway increased, the roof stress increased and then decreased. The theoretical analysis and numerical simulation findings in this study provide a new research method to analyze the stability of the roof-filling body system in GER.

• Journal of Powder Materials
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• v.7 no.4
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• pp.189-196
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• 2000

Effect of ball filling ratio on the behavior of balls motion and their collision characteristic in a tumbler-ball milling of metal powder are investigated by a computer simulation. The discrete element method and the extended Kelvin model composed of nonlinear spring and nonlinear dashpot were employed in the simulation. It can be possible that analysis of the individual balls motion in a three-dimensional actual mill by the two-dimensional model simulation, since the simulated trajectories of ball paths are in relatively good agreement with the actual ones. It knows that the balls motion in the tumbler-ball mill is strongly influenced by the surface conditions of the balls and mill container wall. The energy consumption of the individual balls during impact and the impact frequency of the individual balls increased with an increase in the ball filling ratio and showed maximum values at about 50-60% ball filling ratio, and then decreased.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.931-937
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• 2004

Simultaneous filling is a goal in plastic injection mold that has multi cavities. The moldings which have not been filled at the same time have undesired faults such as dimension inaccuracy, residual stress, law mechanical strength, etc. The best way to simultaneous fill is to be injected in a geometrically balanced runner system. In a general processing, however, in balanced runner system mold, filling imbalance would be observed in cavities. These phenomena result from molten polymer's characteristics and circumstances in balanced runner. In this study, the degree of filling imbalance (DFI) was defined for showing rate of filling imbalance in geometrically balanced injection mold that has 8 cavities. Before the main experiment, an injection molding simulation was conducted to know a pattern of filling imbalance with Moldflow software. There were somewhat differences between results of experiment and simulation about the filling imbalance. The reason for the difference was that the software have not concerned about a situation in a real flow channel. It was also investigated how the injection speed affected on filling imbalance in the experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.543-544
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• 2010

• Journal of Korea Foundry Society
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• v.24 no.4
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• pp.225-230
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• 2004

Computer simulation of mold filling and solidification has been performed in order to analyze the flow and solidification phenomena for the casting process of cylinder liner. The simulation result of mold filling shows that the molten metal flows into the mold in stable without scattering. The simulation results of solidification indicate that the last solidified area is located in the feeder. The temperature variation in casting is measured in actual casting and the result is compared with calculation result.

• Current Applied Physics
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• v.18 no.11
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• pp.1451-1457
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• 2018

Injection compression molding (ICM) is an advantageous processing method for producing thin and large polymeric parts in a robust manner. In the current study, we employed the ICM process for an energy-related application, i.e., thin and large polymeric battery case. A mold for manufacturing the battery case was fabricated using injection molding. The filling behavior of molten polymer in the mold cavity was investigated experimentally. To provide an in-depth understanding of the ICM process, ICM and normal injection molding processes were compared numerically. It was found that the ICM had a relatively low filling pressure, which resulted in reduced shrinkage and warpage of the final products. Effect of the parting line gap on the ICM characteristics, such as filling pressure, clamping force, filling time, volumetric shrinkage, and warpage, was analyzed via numerical simulation. The smaller gap in the ICM parting line led to the better dimensional stability in the finished product. The ICM sample using a 0.1 mm gap showed a 76% reduction in the dimensional deflection compared with the normal injection molded part.