In this study, in order of to reflect the mold deformation in the injection molding process to design of mold, the mold deformation was analyzed by performing flow and structural analysis. The 5 inch LGP(light guide plate) mold, platen and tie bar were modeled and applied to the analysis. The result of melt pressure from flow analysis was extracted for use as boundary conditions acting on the mold surface in the structural analysis. In order to evaluate the accuracy of simulation analysis results, injection molding was performed under the process conditions of simulation. As a results, the mold deformation during injection molding tends to be similar that of injection pressure, and it is confirmed that it shows the behavior and properties of melt resins. Compared with the simulation and experiment, the error of the maximum mold deformation in the injection phase was 4.20%.

목적 : 도수와 안경테의 다른 변수의 변화가 없는데 새로운 안경을 착용하였을 때 불편함을 느끼는 사람을 대상 으로 안경테와 렌즈에 따른 변수를 분류하여 왜곡정도, 커브변화, 어지러움에 미치는 영행을 알아보고자 하였다. 방법 : 도수와 안경의 변수의 변화가 없고 안과적 질환 및 다른 질환이 없는 성인남녀 103명(남자55명 여자48 명) 206안을 대상으로 안경테(재질, 모양, 가공방식)와 안경렌즈별(굴절률, 설계방식, 코팅종류)로 변수를 분석하여 그 변수들이 렌즈의 왜곡정도, 커브변화, 어지러움증에 미치는 영향을 측정하였다. 결과 : 렌즈에 따른 분류에서는 굴절률, 코팅방식에서 왜곡정도, 커브변화, 어지러움의 차이가 있는 것을 확인하 였다. 안경테에 따른 분류에 재질, 안경테의 모양, 가공방식에서 왜곡정도, 커브변화, 어지러움의 차이가 있는 것을 확인하였다. 왜곡정도, 커브변화, 어지러움의 상관분석 결과 어지러움은 상관분석 결과 안경이 왜곡정도 심하면 심할 수록 커브변화가 더 커지는 것을 확인하였고 안경의 왜곡정도가 심하면 심할수록 어지러움 정도가 더 심해지는 것을 확인하였으며. 어지러움은 상관분석 결과 안경의 커브변화가 클수록 어지러움 정도가 더 심해지는 것을 확인하였다. 결론 : 본 연구 결과 사용된 안경테와 렌즈에 따라 왜곡정도, 커브변화, 어지러움에 대한 차이가 나타났다. 따 라서 이를 고려한 안경테와 렌즈의 선택과 그에 맞는 가공이 필요하다고 사료된다.

Animal orthopedic implants are an area that has recently been come into the light due to growing number of single-person households and increasing of interest in pets. The purpose of this study was to investigate a method to design and manufacture a bushing in a desired direction and angle with the environment of use, while the bone joint plate could be stably deformed during animal fracture surgery. It was found that the bone joint plate was capable of deformation in all directions and was designed to be transformed to the desired angle without degrading the basic properties of bending strength. Also, it was found that the bushing-type bone joint plate could be controlled in multiple directions and angle at omni-directional movements(0°-360°) and 0°-10° moving forward, backward and side to side.

본 연구에서는 우라늄 폐촉매 처리 공정에서 발생하는 우라늄 함유 폐기물 대상으로 유리-세라믹 매질 구조의 대형 디스크 소결체 형태로 제작 시, 최종 제작된 소결체의 비등방향 수축 특성 및 변형율 변화를 연구하였다. 본 연구에서는 최대 직경 40 cm를 갖는 다양한 크기 원형 디스크 형태와 원형 디스크의 1/4 크기의 부채꼴 형 소결체를 제작하여 이들의 비등방성 수축 특성을 평가하였다. 60 MPa 압력하에서 만들어지는 성형체는 소결 시 성형체의 크기 및 형태에 관계없이 높은 등방성 수축하였다. 제조된 전체 소결체에 대한 비등방성율은 평균 1.6%이었고 이때 평균 부피 감용율은 37.4% 이었다. 이러한 결과 로부터 국내에서 발생한 우라늄 폐촉매를 처리하기 위한 공정에서 발생하는 우라늄 함유 폐기물은 대형 디스크 형태의 유리-세라믹 매질 형태로 고형화함으로써 높은 안정성과 부피감용 효과를 가지며 200 L 드럼에 포장될 수 있음이 확인되었다.

In this study, the flat glass and adsorption pad were modeled using SolidWorks Simulation, to understand the deformation characteristics of the vertical flat glass by the adsorption pressure during vertical transport of LCD. The horizontal and vertical displacements and equivalent stresses of the flat glass were investigated by the structural analysis. From the displacement and stress visualization according to the adsorption pressure, the higher the adsorption pressure, the larger the glass surface protruded. The horizontal deformation of flat glass increased with increasing thickness and the vertical deformation increased with decreasing thickness. In addition, the maximum equivalent stress applied to the flat glass increased significantly as the adsorption pressure increased and the thickness decreased. As a result of the structural analysis, the thinner the thickness of the plate glass, the greater the effect on the adsorption pressure. Especially, the effect of the adsorption pressure was clearly observed at the thickness of 0.5mm.

Titanium aluminides have attracted special interest as light-weight/high-temperature materials for structural applications. The major problem limiting practical use of these compounds is their poor ductility and formability. The powder metallurgy processing route has been an attractive alternative for such materials. A mixture of Ti and Al elemental powders was fabricated to a mechanical alloying process. The processed powder was hot pressed in a vacuum, and a fully densified compact with ultra-fine grain structure consisting of Ti3Al intermetallic compound was obtained. During the compressive deformation of the compact at 1173 K, typical dynamic recrystallization (DR), which introduces a certain extent of grain refinement, was observed. The compact had high density and consisted of an ultra-fine equiaxial grain structure. Average grain diameter was 1.5 μm. Typical TEM micrographs depicting the internal structure of the specimen deformed to 0.09 true strain are provided, in which it can be seen that many small recrystallized grains having no apparent dislocation structure are generated at grain boundaries where well-developed dislocations with high density are observed in the neighboring grains. The compact showed a large m-value such as 0.44 at 1173 K. Moreover, the grain structure remained equiaxed during deformation at this temperature. Therefore, the compressive deformation of the compact was presumed to progress by superplastic flow, primarily controlled by DR.

일반적인 구조용 강재의 경우 항복변형률의 이상의 변형을 경험한 이후에 하중을 제거하면 재가력되는 시점에 따라 서 재료의 항복강도는 증가하고 연성이 감소하는 현상을 보인다. 원형강관의 경우 철판을 말아서 제작하는 과정에서 철판의 두 께와 원형강관의 직경에 따라서 항복변형률이상의 큰 변형을 경험하게 되고 이러한 변형은 제작된 강관의 구조적인 성능에 많 은 영향을 미친다. 이러한 이유에서 제작과정에 발생하는 변형이 원형강관의 구조성능에 미치는 영향을 파악할 필요가 있다. 따 라서, 이 연구에서는 원형강관을 제작하는 경우에 발생하는 변형에 의한 철판의 항복강도, 인장강도 및 연성 등의 영향을 파악 하기 위해서 강관의 직경 및 두께와 시험편을 채취한 방향을 변수로 다수의 인장실험을 수행하고 이를 분석하였다. 실험 결과 를 바탕으로 원형강판에서 채취한 시험편은 코일에서 채취한 시험편에 비해 항복강도와 인장강도가 더 높았고, 연신율은 낮아 진 것으로 나타났다.

Excellent plastic moldings is possible through optimization of many molding parameters. In particular, the deformation of a plastic part is affected by various factors during molding. Therefore, it is very important to select the optimum molding conditions that minimize the deformation of the molded part. Experimental design is used to select optimal molding conditions. In this study, the molding conditions were selected to minimize the deformation of the electric plastic plug of the electric vehicle using the Taguchi method in the experimental design method. Using the Taguchi Method, we found that the deformation of the plug moldings was reduced by about 7.2% compared to before optimization.

Structural and mechanical effects of the dynamical precipitation in two copper-base alloys have been investigated over a wide range of deformation temperatures. Basing upon the information gained during the experiment, also some general conclusion may be formulated. A one concerns the nature of dynamic precipitation(DP). Under this term it is commonly understood decomposition of a supersaturated solid solution during plastic straining. The process may, however, proceed in two different ways. It may be a homogeneous one from the point of view of distribution and morphological aspect of particles or it may lead to substantial difference in shape, size and particles distribution. The effect is controlled by the mode of deformation. Hence it seems to be reasonable to distinguish DP during homogeneous deformation from that which takes place in heterogeneously deformed alloy. In the first case the process can be analyzed solely in terms of particle-dislocation-particle interrelation. Much more complex problem we are facing in heterogeneously deforming alloy. Deformation bands and specific arrangement of dislocations in form of pile-ups at grain boundaries generate additional driving force and additional nucleation sites for precipitation. Along with heterogeneous precipitation, there is a homogeneous precipitation in areas between bands of coarse slip which also deform but at much smaller rate. This form of decomposition is responsible for a specially high hardening rate during high temperature straining and for thermally stable product of the decomposition of alloy.

The wastegate valve regulates the maximum boost pressure inside the turbocharger to prevent damage to the engine and turbocharger which can occur from overload. However, even though the opening and closing behaviors of the valve should be controlled accurately, thermal deformations of the turbocharger system can lead to excessive distortion of the actuator rod, which can have a significant effect on the turbocharger performance. In this study, thermal deformation analysis of the turbocharger assembly has been analyzed through finite element analysis under operation condition. The result shows that the deformation in the turbine housing is relatively large and actuator rod is bent by thermal load. It causes rotational deformation at the wastegate valve face connected to the rod. And it is efficient to increase the stiffness of the EWGA rod to minimize the rotational deformation of the valve face. It means that the actuator rod should be placed in a position close to the center of the turbocharger to minimize the length of the rod that has the greatest effect on stiffness enhancement.

In the present work, a new hydrogen added argon heat treatment process that prevents the formation of hydrides and eliminates the dehydrogenation step, is developed. Dissolved hydrogen has a good effect on sintering properties such as oxidation resistance and density of greens. This process can also reduce costs and processing time. In the experiment, commercially available Ti-6Al-4V powders are used. The powders are annealed using tube furnace in an argon atmosphere at 700oC and 900oC for 120 min. Hydrogen was injected temporarily during argon annealing to dissolve hydrogen, and a dehydrogenation process was performed simultaneously under an argon-only atmosphere. Without hydride formation, hydrogen was dissolved in the Ti-6Al-4V powder by X-ray diffraction and gas analysis. Hydrogen is first solubilized on the beta phase and expanded the beta phases’ cell volume. TGA analysis was carried out to evaluate the oxidation resistance, and it is confirmed that hydrogen-dissolved Ti-6Al-4V powders improves oxidation resistance more than raw materials.

This study investigates the effect of thermo-mechanical treatment on the damping capacity of the Fe-20Mn-12Cr- 3Ni-3Si alloy with deformation induced martensite transformation. Dislocation, αʹ and ε-martensite are formed, and the grain size is refined by deformation and thermo-mechanical treatment. With an increasing number cycles in the thermo-mechanical treatment, the volume fraction of ε-martensite increases and then decreases, whereas dislocation and α'-martensite increases, and the grain size is refined. In thermo-mechanical treated specimens with five cycles, more than 10 % of the volume fraction of ε-martensite and less than 3 % of the volume fraction of αʹ-martensite are attained. Damping capacity decreases by thermomechanical treatment and with an increasing number of cycles of thermo-mechanical treatment, and this result shows an opposite tendency for general metal with deformation induced martensite transformation. The damping capacity of the thermomechanical treated damping alloy with deformation induced martensite transformation greatly affect the formation of dislocation, grain refining and α'-martensite and then ε-martensite formation by thermo-mechanical treatment.

Many reinforced concrete (RC) buildings constructed prior to 1980's lack important features guaranteeing ductile response under earthquake excitation. Structural components in such buildings, especially columns, do not satisfy the reinforcement details demanded by current seismic design codes. Columns with deficient reinforcement details may suffer significant damage when subjected to cyclic lateral loads. They can also experience rapid lateral strength degradation induced by shear failure. The objective of this study is to accurately simulate the load-deformation response of RC columns experiencing shear failure. In order to do so, model parameters are calibrated to the load-deformation response of 40 RC column specimens failed in shear. Multivariate stepwise regression analyses are conducted to develop the relationship between the model parameters and physical parameters of RC column specimens. It is shown that the proposed predictive equations successfully estimated the model parameters of RC column specimens with great accuracy. The proposed equations also showed better accuracy than the existing ones.

The cooling process in the injection molding requires the longest time. Therefore, a lot of studies have been conducted to reduce the cooling time. In particular, studies on conformal cooling channels using 3D printing are actively being conducted. In this study, the effect of the conformal cooling channel considering the hood shape instead of the conventional linear cooling channel was investigated by injection molding analysis. In the analysis results, when the conformal cooling channel was applied, the length deformation of the molded product was reduced by about 33% and the circular deformation of the hood assembled on the lens was reduced by about 7.1㎛.

This research is about a study on the flow stress of Inconel 601 under hot deformation. For Inconel 601, hot compression tests on gleeble 3500 system under 925℃, 1050℃ and 1150℃ and 0.001/s, and 5/s of strain rates were done. The flow behavior of the Inconel 601 was studied and modeled. In this study, the flow stress was modeled using deep neural network and support vector regression algorithm. The flow stress of Inconel 601 was dependent on strain rate and temperature. It was found that both the deep neural network and support vector regression adequately described the flow stress variation of Inconel 601. However, the model by the support vector regression was found to be superior to the model by the deep neural network. The construction of the model by SVR was more efficient than the construction by DNN. Also the prediction accuracy of the model by SVR was better than the accuracy of the model by DNN. It is found that the MAPE(Mean absolute percentage error) of the DNN based model was 4.89% while the MAPE of the SVR based model was 1.98%.