간행물
한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌
- 발행기관 한국기계기술학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1229-604X (Print)2092-0385 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 기계공학 공학 분류의 다른 간행물
- 십진분류KDC 550DDC 620
권호리스트/논문검색
제26권 제5호 (2024년 10월) 50건
21.
2024.10
구독 인증기관 무료, 개인회원 유료
One of the efficient method for DPF(Diesel Particulate Filter) regeneration of diesel engines is using post fuel injection, which is injected into the combustion chamber during the expansion stroke. This method generates a heat for DPF regeneration by oxidation of HC with Pt coated on DOC(Diesel Oxidation Catalyst). This study investigates heat generation of DOC using post fuel injection.
3,000원
22.
2024.10
구독 인증기관 무료, 개인회원 유료
To efficiently develop an automatic assembly system that can enhance the quality and assembly productivity of the shaft assembly in EV relays, a DMU model was utilized. After modeling each component of the assembly system using the CAD software CATIA, a DMU model of the assembly cells and the entire assembly system was created using the assembly model. Additionally, the DMU Kinematics Workbench was employed to verify and validate the design of the automatic assembly system for the shaft assembly, a key component of the EV relay, before actual construction. This approach helped reduce time and costs by minimizing trial and error.
4,000원
23.
2024.10
구독 인증기관 무료, 개인회원 유료
An electric initiator is a component that is located in the thermal battery or propulsion unit to transfer energy first. Initiator tests include X-ray test, non-destructive leak testing, circuit/insulation resistance test, and CBT (Closed Bomb Test). Among them, CBT is a key element in evaluating the performance of initiator, and the reliability of the test results is important for judgment of the required performance. This study conducted inter-laboratory comparative tests to secure the reliability and repeatability & reproducibility of the initiator CBT. A comparative test was conducted with a mass production acceptance test agency to verify whether the reliability was secured.
4,000원
24.
2024.10
구독 인증기관 무료, 개인회원 유료
Liquid hydrogen, a promising energy carrier, necessitates robust storage and transportation systems due to its extremely low boiling point. Consequently, the development of reliable cryogenic adhesives and standardized testing protocols is crucial. This study focused on optimizing the design of a gripper used in single lap shear tests for evaluating cryogenic adhesives, specifically targeting the challenges posed by low-temperature conditions that induce slippage at the gripper interface. The optimal design was performed using a total of five variables, including the position and size of the gripper. By employing the genetic algorithm coupled with finite element analysis, we exhaustively searched through over 1000 models to identify the optimal gripper geometry. We successfully minimized stress concentration at the gripper region while maintaining a uniform stress distribution on the non-bonded surface. Furthermore, the study explored the impact of symmetric versus asymmetric gripper configurations on test results. The findings revealed that symmetric grippers generally yielded more consistent and reliable data. This study's results enable the accurate and stable execution of lap shear tests under the temperature conditions of liquefied hydrogen.
4,000원
25.
2024.10
구독 인증기관 무료, 개인회원 유료
The lane designation and the bus-only lane system for traffic speed and road safety are difficult to crack down on, and for this purpose, crackdown methods using image recognition technologies are being studied. Existing studies require continuous learning or additional equipment, and it is difficult to classify combined vehicles such as vans and pickup trucks. Therefore, in this study, YOLO and EasyOCR were mixed to classify combined vehicles through vehicle type symbols. For combined vehicles, higher accuracy was shown than classification using YOLO. Due to the nature of Hangul, the accuracy was slightly lowered because the OCR was not accurately recognized, but if it is used with the existing YOLO classification, high accuracy of crackdown will be possible.
4,000원
26.
2024.10
구독 인증기관 무료, 개인회원 유료
Design of Support Diameter of Liquid Hydrogen Storage Tank Using Thermal-Structural Coupled Analysis
The recent surge in energy consumption has sharply increased the use of fossil fuels, leading to a steep rise in the concentration of greenhouse gases in the atmosphere. Interest in hydrogen is growing to mitigate the issue of global warming. Currently, hydrogen energy is transported in the form of high-pressure gaseous hydrogen, which has the disadvantages of low safety and energy efficiency. To develop commercial hydrogen vehicles, liquid hydrogen should be utilized. Liquid hydrogen storage tanks have supports between the inner and outer cylinders to bear the weight of the cylinders and the liquid hydrogen. However, research on the design to improve the structural safety of these supports is still insufficient. In this study, through a thermal-structural coupled analysis of liquid hydrogen storage tanks, the model with three supports, which had the lowest maximum effective stress in the outer tank, inner tank, and supports as proposed in the author's previous research, was used to create analysis models based on the diameter of the supports. A structurally safe design for the supports was proposed.
4,000원
27.
2024.10
구독 인증기관 무료, 개인회원 유료
Multidisciplinary Design Optimization(MDO) method that considers principles in various fields affecting big scale structure and system design at the same time is used. Because most variables are connected many engineering phenomena under the classic optimized design method(all-in-one design approach), it is hard to judge the meaning of final design solution obtained, and there are cases where all variables converge before reaching the optimal design value in large-scale design problems with many variables. Collaborative Optimization (CO) method, the most advanced MDO approach, is used to efficiently solve these optimum problems, to efficiently analyze design problems involving numerous design variables and constraints and in which various engineering phenomena occur. However, the application of the MDO problem to CO introduces a number of numerical problems by destroying the numerical properties of the original optimal design problem. Therefore, this study researches one solution by listing the problems of CO after organizing various approaches of MDO.
4,000원
28.
2024.10
구독 인증기관 무료, 개인회원 유료
Wireless sensor systems are primarily used for monitoring natural environments or industrial automation. The physical environment where these systems are installed is often unstable, making it difficult to replenish sensor energy immediately. Complex and harsh conditions can impact the network's structure, affecting monitoring performance. Wireless sensor systems consist of hundreds of sensors that collect data from hazardous environments and transmit information to a central system. However, due to the system's physical structure, information delays or losses may occur. This paper proposes a distance-based tree structure to address these issues in wireless sensor systems, and experimental results confirm its superior performance.
4,000원
29.
2024.10
구독 인증기관 무료, 개인회원 유료
This study aimed to develop a systematic process for identifying components that need to be changed to reduce the Head Injury Criterion (HIC) during pedestrian headform tests. Through simulation and analysis, it was confirmed that the hood, hinge, hinge plate, cowl, fender, and fender bracket significantly influence HIC15. The study identified the specific impact of each component on HIC15, allowing for targeted improvements. The proposed process demonstrated superior performance compared to single-component optimization, yielding more significant reductions in HIC15. Multiple vehicle models were tested, confirming the process's effectiveness in consistently lowering HIC15 values.
4,000원
30.
2024.10
구독 인증기관 무료, 개인회원 유료
In this study, the calorimeter was used to experimentally investigate the heating characteristics of the variable A/C system according to changes in loading time and outdoor dry bulb temperature. The heating capacity, COP and compressor discharge temperature were measured while changing the loading time of the compressor. To develop the correlation for compressor discharge temperature, loading time, indoor dry bulb temperature and outdoor dry bulb temperatures were considered as operating variables. As the outdoor temperature and loading time increased, the heating capacity and COP increased. However, the change in COP showed different trends depending on the outdoor temperature. The evaporation temperature according to the loading time is a good estimate of the outdoor temperature. However, as the temperature difference between indoor and outdoor rooms decreases and the loading time increases, the condensation pressure increases significantly, so the condensation temperature increases. The maximum deviation between the correlation and the experimental value for compressor discharge temperature was within approximately 2℃.
4,000원
31.
2024.10
구독 인증기관 무료, 개인회원 유료
Driving Resistance is calculated for emission test defines total vehicle resistance forces. Resistance factors of running vehicle are sum of rolling resistance, transmission loss and aerodynamic drag force. To measure this resistance, Coastdown test is conventional method and it needs a long level driving road. In this study coastdown test is executed on short driving road. And also each resistance factors are calculated. This test is based on S(Distance)-Time Method. From the result, it is shown that this method is reliable and can be used for initial vehicle test.
3,000원
32.
2024.10
구독 인증기관 무료, 개인회원 유료
The hydrogen valve used in this study is intended to be applied to a automobile, and since there is a limit to the length of the stem, it is necessary to review the optimized stem, and for this, it is required to investigate the heat transfer characteristics of the hydrogen shut-off valve. For this, the temperature of the entire shut-off valve and especially the plunger and O-ring, which are key components in the solenoid valve driving the hydrogen shut-off valve, was calculated using the ANSYS-CFX flow analysis program. From the analysis results, the length of the stem capable of maintaining the design temperature of -40℃ or higher should be at least 139 mm, and it is judged that it should be 140 mm or more considering safety. When determining the stem length of the hydrogen blocking valve for automobiles, constraints on installation in automobiles should be considered.
4,000원
33.
2024.10
구독 인증기관 무료, 개인회원 유료
The 81mm mortar barrel is a precision component requiring exact internal diameter measurements, which poses challenges in both machining and inspection using conventional equipment. This study addresses issues related to measurement variability and reprocessing due to inconsistencies in bore measurements along different barrel positions. Using Gage R&R analysis, we identified the limitations of the existing measurement system, particularly its inability to provide consistent and detailed readings along the full barrel length. To resolve these challenges, a revised measuring system was developed and compared with the existing system, showing enhanced accuracy and reduced errors. The improved system was subsequently applied to the barrel machining process, resulting in quality improvements in the final product.
4,000원
34.
2024.10
구독 인증기관 무료, 개인회원 유료
The design and implementation of acoustic metamaterials have garnered significant interest for their potential in noise and vibration reduction and control. However, the process of fabricating metamaterials is often perceived as challenging and confined to specialized fields. In this study, we aim to remove these barriers by demonstrating that it is possible to design and implement acoustic metamaterials using a simple array of commonly available PVC pipes. We designed and fabricated metamaterials using PVC pipe arrays and validated their performance through both numerical simulations and experimental testing. The experiments were conducted using standard audio equipment, and the results showed consistent trends with the numerical simulations. This research demonstrates that acoustic metamaterials can be effectively realized using accessible materials like PVC pipes, providing a practical approach to noise reduction and control.
4,000원
35.
2024.10
구독 인증기관 무료, 개인회원 유료
Onboard truck scales can accurately measure payload under static conditions. However, their performance is limited in accounting for dynamic environments encountered during driving, leading to inaccuracies in load estimation under real-world conditions. This study employs TruckCaliber, a dynamic state measurement system, to estimate real-time vehicle loads. Fusion sensor modules were installed on leaf spring suspensions and vehicle frames to collect tilt and IMU data. The system was implemented on a commercial truck, and driving tests were conducted with varying payloads. The analysis focused on curved sections under different dynamic conditions.
4,000원
36.
2024.10
구독 인증기관 무료, 개인회원 유료
This paper delves into the standard system for selecting aviation tools. Generally, standards are seen as foundational and fundamental. However, in actual practice, there are often instances where a thorough differentiation of the standard unit system isn't properly executed, resulting in product defects in certain companies. Therefore, through the insights gathered in this study, we aim to reaffirm the basic principles and move forward with the objective of manufacturing products of impeccable quality in accordance with future quality improvement policies. Ultimately, we aspire for K-Defense to emerge as a prominent leader in the global market.
4,000원
37.
2024.10
구독 인증기관 무료, 개인회원 유료
In this study used Computational Fluid Dynamic analysis to examine NOx reduction in hydrogen combustion, analyzing six conditions with varying air/fuel ratios, temperatures, and concentrations. Results were compared between two combustor shapes and previous experimental data. Findings showed increased air/fuel ratios decreased flame temperature and increased post-combustion O2. NOx emissions peaked at high temperatures and low O2. Numerical results aligned with previous experimental trends, validating the approach. Combustor shape differences, reflecting variations in fuel and air pipes, significantly affected flow rates and combustion positions. This reduced NOx emissions up to a certain air/fuel ratio, but excessive increases diminished this effect. The study highlights the complex relationship between combustor design, operating conditions, and NOx emissions. Further research is needed to optimize NOx reduction by considering pipe numbers and combustion locations. Future studies should explore various combustor geometries, fine-tune air/fuel ratios, and investigate additional parameters influencing NOx formation and reduction in hydrogen combustion systems.
4,000원
38.
2024.10
구독 인증기관 무료, 개인회원 유료
This study uses a frequency analyzer to measure and analyze the major alarm sounds of vehicle selected by domestic car manufacturer and car size, which are continuously improving in accordance with the continuous development of the automobile field. Therefore, the purpose is to find the alarm sound that modern people can hear best and find improvement measures accordingly. In the past, only the driving performance of vehicles was considered important, but as the industry and science developed, research was conducted to satisfy not only the driving performance of vehicles but also the comfort and emotional needs of drivers, such as ride comfort, safety, and noise issues. At the same time, it is progressing actively and continues to develop.
4,000원
39.
2024.10
구독 인증기관 무료, 개인회원 유료
This study focuses on optimizing the uniform pressing process in precision manufacturing, addressing challenges posed by surface roughness and height differences between components. In real-world conditions, such irregularities can lead to non-uniform pressure distribution during pressing, negatively affecting product quality. To mitigate these issues, a buffer protection layer was introduced between the press and components. The optimization process was conducted through finite element analysis (FEA) to determine the ideal material properties, including elastic modulus, Poisson's ratio, and thickness of the buffer layer. Two surface roughness scenarios were examined to assess the impact of surface conditions on pressing uniformity. The results indicate that a higher elastic modulus, Poisson’s ratio, and thicker buffer layers are more effective in achieving uniform pressing, particularly under rougher surface conditions. This study provides a practical solution for improving the precision and reliability of pressing processes, ensuring better product consistency and enhancing overall manufacturing efficiency.
3,000원
40.
2024.10
구독 인증기관 무료, 개인회원 유료
Aerial work platform truck is used in various ways depending on the surrounding environment, of city roads, farming areas, and industrial sites. Air flow, drag force and torque in surroundig the flow field of AWP have been analyzed with CFD method. The overall air flow rate decreases as the AWP passes and increases between the vehicle and the boom, at the boom connections, and at the bottom of the work platform. The drag force and torque on the boom, workspace, and the combined boom and workspace are largely affected by air flow velocity. The boom's drag and torque are approximately 2.2 and 1.3 times greater than those of the work platform, respectively. These predicted results can be widely applied as basic conceptual design data for highly efficient aerial work platform truck.
4,000원
