Recently, automobile washing methods have been carried out using steam of high temperature and high pressure instead of water. Therefore, it is necessary to secure the structural stability of the steam tank. In this study, it is necessary to reduce the weight of the steam tank by reducing the thickness of the existing steam tank by about 25%. The safety of the product design was verified through simulation to ensure the robustness of the product by securing the structural stability and fatigue analysis at high temperature and pressure of the steam tank according to the weight reduction. For newly developed products compared to existing models.

In this study, temperature and pressure of guided wave radar products are transmitted at high temperature and high pressure. In the case of transmission of temperature pressure, high temperature and high pressure steam leak from the guide rod part to the atmosphere causes the failure. Therefore, in this study, structural analysis and thermal flow analysis of the product are performed to identify the problem of the product, so as to prevent leakage in the product development by grasping the cause of the leakage of the product. In this study, if the method of assembling the lower end of the piston rod and the gasket is changed from line contact to face contact,

There are many studies to extend the distance traveled by electric vehicles. However, much research has been done to increase the capacity of the battery. In this study, some engines for power generation, in which a battery is charged with energy by mounting a small internal combustion engine in which an engine is mounted in an electric vehicle and the battery is charged with energy, are being studied. Therefore, since such an engine is operated at a high load, the camshaft and the camshaft are emphasized to have high load strength and durability to withstand fatigue.

대형 유조선에서 유류의 선적이나 하역에 사용되는 장치인 COPT (Cargo Oil Pump Turbine) 가 매우 큰 형태이므로 이 터빈을 회전시키는 장치가 Rotor disc로서, 내부에 stator ring이 장착되어 있고 이 ring에는 많은 turbine blade가 riveting 방법에 의해 체결되어 있다. riveting 은 재래식 가공 방법으로서 정밀도와 작업자의 근 골격계 직업병 등 많은 문제점을 포함하고 있다. 이러한 문제를 해결하기 위해 riveting 체결방법을 조립방법으로 전환하여 링의 조립정밀 도를 향상하고 stator의 수명을 연장시킬 수 있다. 많은 turbine blade가 링의 중심점을 기준으로 원주상에 배열되어 있는 형태로서 조립을 위한 구조개선을 필요로 한다. 이런 목적을 달성 하기 위해서는 ring 구조를 결구 방식으로 변경하고 조립 후 COPT에 적용하였을 때 안전성이 보장되어야 한다. Stator 링의 모델링과 구조안전성에 대한 검증은 상용 software를 이용하여 결과를 도출한다.

The design and analysis of the rigidity and deformation of the vehicle body are basically performed in two forms. First, the relative response of components separated from a parent system or connected as a model of a subsystem is examined. Second, the entire model is used to consider the absolute response of the components to the externally transmitted vehicle service load, which is defined as that of the entire vehicle body system. In this paper, we propose the finite element modeling for the structural design of the car body. First, we will explain the simple finite element modeling of the car body, explain the method of formulating the stiffness of the joint, and finally the shell element. The proposed finite element modeling is proposed. By applying the proposal, it is possible to propose finite element modeling of all medium and large passenger cars less than 3 tons.

The structural performance of a vehicle can be evaluated by the static and dynamic structural analyses which predict the amount of deformation, stiffness. And the static analysis should be done first. Another important aspect to be considered in the design process is crashworthiness, because a structurally sturdy vehicle body may be overdesigned with excessive strength and durability standards. The ideal condition of a body structure is to absorb impact load at a certain level of local deformation, to distribute the load to each structure adequately, and to prevent excessive stress concentration and deformation. This paper is the result of the consideration of automotive body, bending and torsional stiffness for structure stiffness estimation of automotive body through finite element modeling.

Fabrication of soft magnetic composite powders for the Fe2O3-Ca system by mechanical alloying(MA) has been investigated at room temperature. It is found that soft magnetic composite powders in which CaO is dispersed in α-Fe matrix are obtained by MA of Fe2O3 with Ca for 5 hours. Changes in magnetization and coercivity also reflect the details of the solidstate reduction process of hematite by pure metal of Ca during MA. The saturation magnetization of MA powders increases with increasing MA time and reaches a maximum value of 65 emu/g after 7 hours of MA. The average grain size of α-Fe in MA powders, estimated by diffraction line-width, gradually decreases with increasing MA time and reaches 52 nm after 5 hours of MA. It can also be seen that the coercivity of the 5-hour MA sample is fairly high at 190 Oe, suggesting that the grain refinement of already-produced α-Fe tends to clearly occur during MA.

PE(PolyEthylene) 재료를 활용한 해상부유 구조물은 바다, 강 또는 호수의 인근이나 수역 내에 일정한 공간 부를 형성하는 부유식 구조물로, 현재는 그 용도가 소형선박 계류장뿐만 아니라 양식장, 수상 펜션, 해상부교 등에 다양하게 활용되고 있다. 이 제품군의 특징은 유연성이 뛰어나고 재활용할 수 있으며, 내약품성, 내후/내식성이 우수하다. 기존의 PE 제품군을 활용한 부유식 플랫폼은 한 개의 브래킷에 한 개의 부력관을 체결하는 단순한 구조를 구성하였고, 이로 인하여 사용자가 용도 변경 및 사용환경이 변경될 때는 적용하는데 제한이 있었다. 이에 본 연구에서는 한 개의 브래킷에 다양한 크기를 갖는 부력 관을 체결할 수 있는 구조를 개발하고, 제품의 구조 안전성을 유한요소법을 활용하여 검증하였다. 구조해석 결과, 브래킷 하단에 지름 500mm 부력관 모델에서 충돌 하중에 대해 최대값을 나타내었으나, 허용기준을 만족하였다. 본 연구 결과를 기반으로 하여, 향후 다양한 형태의 부유체 플랫폼에 대한 구조 안전성 평가에 관한 연구가 가능하며, 관련 평가 기준에 대한 정립이 필요하다.

This study analyzes the mechanical properties, including the attrition rate, of 50 μm size yttria-stabilized zirconia (YSZ) beads with different microstructures and high-energy milling conditions. The yttria distribution in the grain and grainboundary of the fully sintered beads relates closely to Vickers hardness and the attrition rate of the YSZ beads. Grain size, fractured surfaces, and yttrium distribution are analyzed by electronic microscopes. For standardization and a reliable comparison of the attrition rate of zirconia beads with different conditions, Zr content in milled ceramic powder is analyzed and calculated by X-ray Fluorescence Spectrometer(XRF) instead of directly measuring the weight change of milled YSZ beads. The beads with small grain sizes sintered at lower temperature exhibit a higher Vickers hardness and lower attrition rate. The attrition rate of 50 μm YSZ beads is measured and compared with the various materials properties of ceramic powders used for high-energy milling. The attrition rate of beads appears to be closely related to the Vickers hardness of ceramic materials used for milling, and demonstrates more than a 10 times higher attrition rate with Alumina(Hv ~1650) powder than BaTiO3 powder (Hv ~315).