간행물

한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌

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제24권 제5호 (2022년 10월) 34

21.
2022.10 구독 인증기관 무료, 개인회원 유료
The Moving Particle Semi-implicit (MPS) method is one of most famous method in the particle-based computational fluid dynamics field. The MPS, the state-of-art method, is simple but intuitive methodology including multi-phase and complex structure interactions problems. However, the concept of particle method may contain the physical weakness. In order to avoid physical violence, the particle number density and kernel function were employed. Despite all the efforts, the microscopic problems were not easily resolved yet. In this study, the surface tension model was developed and added into the MPS method to strengthen physical phenomena and physics laws. The simulation result with new MPS method including surface tension model was compared with corresponding theoretical results and they show good-agreement.
4,000원
22.
2022.10 구독 인증기관 무료, 개인회원 유료
The need for research on a sensor system that can monitor the dynamic load of a commercial vehicle in real-time is emerging because the development of autonomous vehicles is actively progressing worldwide. In this study, dynamic load measuing system of commercial vehicles was developed using the MEMs inclinometer attached to the leaf spring suspension. Test vehicle’s driving test was accomplished by changing speed and payload weight in several stages. Using the dynamic load measurement system, it was possible to check the weight shift and the change of stopping distance. When a driving speed increases from 30km/h to 80 km/h, the stopping distance increases from about 25m to 80m.
4,000원
23.
2022.10 구독 인증기관 무료, 개인회원 유료
In this paper, we propose a dynamic stability prediction method for heavy vehicles based on Lateral Load Transfer Ratio. The key factors influencing vehicle roll motion are the vehicle's load, the position of the center of mass, the tread and the vehicle speed. Using these factors, we derive the lateral load transfer ratio (LTR) formula. In addition, we investigated LTR changes and vehicle rollover of heavy vehicles in various scenarios using TruckSim. As a result, the threshold value of the change rate of the LTR at which the vehicle rolls over was 0.68-0.72. Finally, we performed a numerical experiment to prevent rollover by calculating the optimal speed in the rollover situation.
4,000원
24.
2022.10 구독 인증기관 무료, 개인회원 유료
Additive manufacturing is a new approach to design and production. This applies in particular to processes such as repair and rework of selected components. Additive manufacturing can produce almost any shape, and from an MRO part perspective, additive manufacturing offers tremendous advantages. The special feature of additive manufacturing is that it is particularly economical for small-volume production as the number of units is irrelevant compared to the existing manufacturing process. The purpose of this study was started from the MRO point of view, and it Identify changes and respond to the Blisk It is a study on the effect of changing the conditions on the path of the toolpath and the CAM during additive manufacturing using CAM after finding suitable conditions. metal powder.The metal powder withstands various corrosive environments and age hardening occurs very slowly. Inconel 718, which can be used in various applications such as nuclear facility-related parts, aerospace, oil facilities, turbines, and valves, was used. This is SUS 316L with good high temperature strength. The variable of the laser used in the study is the laser power, and the variables on the CAM are Operation, Stepover, Pattern, etc. In the relation between laser power and feed, when feed is specified as 500mm/min, laser power of 700W was most suitable. As for the conditions on NX CAM, ADDITIVE PROFILE Stepover was 0.8mm for Operation, and Infills and Finish for Pattern. When stacking, each layer should be overlapped with the result. Therefore, the stepover should be smaller than the laser spot size and reprocessing should be done in terms of repair, so infills and finish were applied to work larger than the actual product shape.
4,000원
25.
2022.10 구독 인증기관 무료, 개인회원 유료
In this study, the following results were obtained by designing a high-efficiency hydrogel and colloid fusion applicator and checking production speed(hydrogel) and working setting time(coating time) by promoting the starting product. As a result of performing a product production test by manufacturing a starting product based on the process automation design, the production volume increased by about three times from 4m per minute to an average of 11m per minute. The working setting time(coating time) of the fusion applicator was shortened from the target of 10minutes to 1.69minutes, which had the effect of reducing the loss of work time.
4,000원
26.
2022.10 구독 인증기관 무료, 개인회원 유료
Burr occurs at the bottom of the material as the material breaks during shearing, and sliver occurs in shear droop that occurs when a punch penetrates the surface of the material. Sliver refers to the shape of a long and thin thread, and it is an important defect that can cause a short when assembled into electronic parts other than a defect in the appearance of a product, an assembly defect in the post-process, and an injury to the operator. Sliver does not occur when the molding is completed only by the main shearing without pre-shearing, but sliver occurs when the main shearing is performed after the pre-shearing. The purpose of this study is to study the sliver generation mechanism that occurs during main shearing after pre-shearing. Using the material phosphor bronze C5210-EH(HP), the sliver was observed with the dimensions and stripping force of the pre-shearing as variables, and the effect of the pre-shearing on the sliver was studied. The product used in the experiment is a terminal, a press product that is assembled on a 0.4mm pitch FPC connector. Three experimental variables were selected: the X-axis allowance, the Y-axis length, and the stripping force in the dimensions of the pre-shearing. As a result of 12 experimental conditions, the X-axis allowance had a greater effect on sliver generation than the Y-axis length and stripping force. The cause of sliver during pre-shearing is that the shear droop part is elongated due to bending when the punch is lowered due to the hole in the bottom due to pre-shearing.
4,000원
27.
2022.10 구독 인증기관 무료, 개인회원 유료
The global power generation industry is becoming a key power generation industry with gas power generation and renewable energy solar power generation. This research aims to focus on solving two problems as a method to improve the solar light collection efficiency among fixed variable deformation methods. Maintaining the proper temperature of the water injection device through automatic temperature detection to solve efficiency degradation, and establishing an automatic operation system by finding the optimal angle for each season, are intended to derive a value that can represent the optimal power generation.
4,000원
28.
2022.10 구독 인증기관 무료, 개인회원 유료
Level 3 driving, which enters full-fledged autonomous driving, is becoming more common. And research on autonomous driving is growing rapidly. Therefore, there is a need for a hardware platform to implement autonomous driving, but the actual vehicle price is too high and the implementation conditions are very limited, so its usability is inevitably reduced. In this study, by providing an easy-to-access hardware platform for anyone to support autonomous driving research, compatibility with software platforms can be increased. As a result of this study, it is possible to conduct hardware platform and software platform education at the same time. Through this, trial and error due to errors in each of the two platforms can be reduced. In addition, various sensors, such as camera sensors and LiDAR sensors, were installed on the hardware platform, and a hardware platform capable of testing autonomous driving for education and R&D was conducted not only outdoors but also indoors with little external environmental impact.
4,000원
29.
2022.10 구독 인증기관 무료, 개인회원 유료
This study was evaluated based on the items of KS B 6389. The study on the calculation of angular error and measurement uncertainty of HRc hardness measurement using statistical techniques using Rockwell measurement specimens with different hardness values ​​was analyzed, and the results were derived according to the change in the angle of the indenter part of the hardness tester and the specimen. As a result of the experiment, the test statistic P values ​​for angle changes such as 0°, 1°, and 2° were all 0.000 using the HRc 30 and 40 measurement specimens, so it was confirmed through the experiment that a significant difference occurred between them. In addition, the extended uncertainty value was calculated as 0.612 at the 95.45% confidence level, and the fact that the hardness test value came out smaller than the existing test value as the inclination angle increased was verified through experiments.
4,000원
30.
2022.10 구독 인증기관 무료, 개인회원 유료
Screws are the closest and most familiar mechanical elements of everyday life, and are generally used so widely that there is no machine without screws. Screws are used to make it easier to combine objects with objects, and are also used to transfer large forces from machines. The most influential factor in the coupling of these screws is the effective diameter. If the effective diameter is not accurate, the support cannot be finished or endured, leading to a major accident. The importance of these screws cannot be ignored, so in this study, the effective diameter was measured using the three-wire method, the screw micrometer method, and the projector method, and the one-way factor design method was applied to determine the exact method compared to the KS standard.
4,300원
31.
2022.10 구독 인증기관 무료, 개인회원 유료
For observation training of firing weapons, military operates Joint Fire Training Simulator system. During the acceptance test for deployment of weapon system, it occurred that could increase training fatigue in mock observation device. This study describes in cause analysis and improvement activities to solve it. Due to the characteristics of observing training with a small image panel through the ocular, image noise and skipping are factors that cause fatigue to training. It was analyzed that the noise of image was caused by HDMI (High-Definition Multimedia Interface) splitter and design change was promoted. In addition, it was determined that the image skip occurred due to the software filter for stabilizing the image of mock observation device. It was solved by improving the calculation error of accumulating data. Securing the quality of observation images is expected to reduce training fatigue and contribute to improving the training environment.
4,000원
32.
2022.10 구독 인증기관 무료, 개인회원 유료
The existing production and manufacturing process was manually operated and the cleaning process was not constant due to poor environmental conditions for several hours, so the production efficiency was significantly lowered and manufacturing cost was increased. In this R&D, productivity improved by doubling the production of 300 units per hour to 700 units, and in this development, manufacturing costs were lowered through this process improvement project based on automotive shoba automation technology.
4,000원
33.
2022.10 구독 인증기관 무료, 개인회원 유료
Thin-film shape technology is recognized for its core technology to enhance the technology of LCD, PDP, semiconductor manufacturing processes, hard disks and optical disks, and is widely used to form coated thin films of products. In addition, resistance(electron beam filament) technology for heating is used to manufacture filament for ion implants used in semiconductor manufacturing processes. By establishing an electronic beam filament production system and developing seven specifications of electronic beam filament, it is contributing to improving trade dynamics and increasing exports to Japan through localized media of theoretical imports to domestic companies. In this study, CAE analysis was performed after setting electron beam filament specification and development objectives, facilities and fabrication for electron beam filament production, electron beam filament JIG & fixture design and fabrication followed by electron beam filament prototype. Then, the automation and complete inspection equipment of the previously developed electronic beam filament manufacturing facilities was developed and researched to mass-produce them, to analyze and modify prototypes, design and manufacture automation facilities, and finally, to design and manufacture the complete inspection equipment. In this paper, mainly electron beam filament specification analysis and development objectives and CAE analysis were dealted with.
4,000원
34.
2022.10 구독 인증기관 무료, 개인회원 유료
The SLA 3d printer is the first of the commercial 3D printer. The 3D printed output is printed hanging on the bed that move to the upper position. Sandblasted bed is used to prevent layer shift. If sandblasting is wrong, the 3D printed output is layer shifted. For this reason, 3D printer manufacturing companies inspect the bed surface. However, the sandblasted surface has variety of irregular shapes and craters, so it is difficult to establish a quality control standard. To solve problems, this paper presents a standardized sandblasting histogram and threshold. We present a filter that can increase the classification rate.
4,000원
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