In this study, the experiments and analyses were carried out in order to investigate the fracture characteristics on the adhesive at the specimen bonded with aluminum and aluminum-foam. The same conditions were given for the experiments and analyses. The results are investigated by the graph of reaction force according to displacement. It was found that the experimental and the analytical data were very similar to each other. On the basis of the data, the reliability of the analysis data could be confirmed. The notches were produced at the distances of 40, 110, 150, and 190 mm from the front of the test specimen, and the maximum reaction force was compared accordingly. It was found that the highest reaction force was generated at the front end of the adhesive and the lowest reaction force was found at the middle of the adhesive interface. Finally, when the equivalent stress in the test specimen was examined, it was found that the highest stress was obtained at the distance of 110 mm. It can be deduced. As the notch formation point are similar to the point when stress is dispersed as the adhesive is peeled off, it is possible to infer the high stress compared to other test specimens.

In this study, we investigated the properties of adhesive materials with different lightweight materials such as CFRP and Al-foam. The specimens were tested and analyzed using DCB (Double Cantilever Beam) specimens. In order to secure the reliability of the finite element method, the test and analysis were carried out, and the reliability of the finite element method was secured by using the graph of reaction force to displacement based on the experiment and analysis. The study on the adhesive failure characteristics according to the position of notch hole proceeded. Notch holes were generated at the locations of 40, 110, 150 and 190 mm from the beginning of the specimen near the bonding interface, and the analysis conditions used were the same as those used for securing reliability. The obtained study results are compared with reaction force and equivalent stress. In the case of reaction force, the overall tendency is similar but the difference in maximum reaction force is found. It was found that higher reaction forces appeared at the beginning than at the end of the bonding interface. When the equivalent stresses in the specimens were examined, the value of CFRP was seen to be 30 times higher as much as that of Al-foam.

The composite material has the strong durability and light weight as inhomogeneous material. Nowadays, CFRP composite has been noticed as the light weight, high strength and long fatigue life. This study has been carried actively. In this study, the properties of tensile strengths of CFRP, stainless steel are analyzed, and compared each other. In order to secure the data, the tensile specimens with notches of same size by using CFRP, and stainless steel are manufactured and experimented. When the forced displacement of about 11.5 mm proceeds in case of stainless steel specimen, the maximum load of 31000 N is shown simultaneously with the fracture of specimen. When the forced displacement of about 6 mm proceeds in case of CFRP specimen, the maximum load of 16000 N is shown. So, the structural safety becomes highest at CFRP specimen among these specimens. In this study, the finite element analysis is carried out in order to compare with the experimental results. It is verified that the experimental and analysis results are similarly shown each other. Through the result of this study, it is thought that the simulation analysis data with no experiments are trustworthy at using as the real tensile experimental data.

Composite materials have the strong durability and light weight as inhomogeneous material. These material are manufactured by combining and maximizing the advantage of each material. Among these various materials, stainless steel, aluminum and brass has been used generally. Prior to using, the preparatory experiments are demanded in order to obtain the material strengths. In this study, the tensile tests are carried out with the specimens of stainless steel, aluminum and brass. These tensile specimens of same standards are made with the notches at both sides of specimen. When the forced displacement of about 11 mm proceeds in case of stainless steel specimen, the maximum load of 31000 N is shown simultaneously with the fracture of specimen. When the forced displacement of about 6 mm proceeds in case of aluminum specimen, the maximum load of 20600 N is shown simultaneously with the fracture of specimen. When the forced displacement of about 7 mm proceeds in case of brass specimen, the maximum load of 25000 N is shown. In this study, the finite element analysis as ANSYS program is carried out in order to verify these experimental results. The experimental and analysis results are similarly shown each other. Through the result of this study, the analysis data with no experiments are thought to be trustworthy as the tensile experimental data.

To control the flow of fluid, several kinds of valves are used. Especially, Main Control Valve (MCV) is the key element of hydraulic system which performs complex control not only controlling the flow of fluid, but also prevent damage of equipment by supplying proper hydraulic pressure to actuator and draining over-supplied hydraulic pressure. While general control valves are producing in domestically, entire quantity of main control valves are depended on importation and it depreciates competitiveness in cost, and time. In this study, to derive the best design of notch structure by following the orifice flow of 6-linked main control valve and the relation between “notch structure” which is the most fundamental element to control the velocity of the fluid and “pressure distribution”, the flow characteristic is compared by comprehending hydraulic pressure and velocity of the fluid using CFD simulation when spool valve is used for “meter-in” and “meter-out” through the opening of the notch structure.

The hydraulic equipments has a high utilization in the many works such as the excavation, planation and crane works in the construction sites. They are an essential equipments in the construction site and the loading & unloading works of the large size objects. In the many parts which are composed of the hydraulic equipments, the main control valve(MCV) is the core of the equipments. The hydraulic energy from the pump controls the direction and the rate of flow by MCV. And the flow rate of the MCV inlet operate some actuators to perform the diverse action of the spool. So, it is important to analysis the shape of the flow path and the notch of the spool. In order to perform the optimal design of the 6-way valve, the study for the analysis of the flow path and the pressure distribution according to the pressure control, which to meet use condition, must be performed. In this study, we carried out the reverse-engineering of the MCV using the parametric technique as the first step in the research of the MCV. And we analyzed the shape of the flow path and the pressure distribution for the notch of the spool using the optimal modeling of the MCV.

샤피 V-노치 충격 하중-변위 곡선으로부터 얻은 균열정지하중을 이용하여 원자로압력용기강의 균열정지파괴인성(KIa)을 예측할 수 있는 방법을 모색하고 그 타당성을 고찰하였다. 샤피충격 하중-변위 곡선으로부터 얻은 균열정지하중값의 변화는 특성온도로 보정된 지수함수의 형태로 잘 표현될 수 있었다. 특성온도 TPa=2kN은 실험적인 무연성천이온도(TNDT) 및 T41 J과 높은 상관성을 나타냈으며, 원자로압력용기강의 균열정지파괴인성을 표현하는 새로운 특성온도로 사용할 수 있을 것으로 판단되었다. 또한 균열정지하중값의 변화는 파면으로부터 측정된 안정균열길이의 변화와 매우 높은 상관성을 나타내었다. 따라서 무딘 노치를 갖는 시편에 대한 계장화샤피충격시험을 통하여 균열정지하중 및 안정균열길이를 측정하믈써 비교적 정확하게 원자로압력용기강에 대한 하한값의 파괴인성치(KIa)를 평가하는 것이 가능한 것으로 판단되었다.

Nochi' is one of Korean traditional panfried rice cakes made from glutinous rice or millet and malt. The optimum conditions for the preparation of 'Nochi' were investigated. The α-amylase activity of malt was 62.5 units/g dry malt and β-amylase 1.43 units/g dry malt. Reducing sugar content of 'Nochi' increased with the content of malt and saccharifying time. Both the hardness and cohesiveness of 'Nochi', measured by rheometer, were decreased with increasing the content of malt, while adhesiveness and hardness increased with saccharifying time, but cohesiveness decreased. The optimum conditions for the preparation of 'Nochi' were 8.0%(w/w) of malt and 1 hour 45 minutes of saccharifying time.