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
제25권 제6호 (2023년 12월) 44건
21.
2023.12
구독 인증기관 무료, 개인회원 유료
The heat transfer characteristics of double-pipe spiral heat exchanger were investigated by various curvature sizes, experimentally. The three different sizes of heat exchanger were made and tested with water as a working fluid to analyze the heat transfer characteristics. The heat transfer rates, overall heat transfer coefficient and pressure drop were analyzed with various heat exchanger sizes (i.e., curvature ratios). As result, the heat transfer rate increased with increasing the size of the heat exchanger as the flow rate increased due to increasing the area size of heat transfer. However, the overall heat transfer coefficient and pressure drop increased with decreasing the heat exchanger size (i.e., increased curvature ratio) due to the enhanced centrifugal force and inertia.
4,000원
22.
2023.12
구독 인증기관 무료, 개인회원 유료
This paper is a study of a prototype development project in progress as part of an industry-academia joint technology development task. The so-called bird collision test equipment is a study to prove the validity of the performance and function content of the test equipment through the speed measurement of the specimen corresponding to the bird and other test procedures to evaluate its function by developing the bird collision test equipment, and the research and development goal is to establish a bird collision simulation test environment and develop data performance methods through this industry-academia study.
4,000원
23.
2023.12
구독 인증기관 무료, 개인회원 유료
An in-wheel motor is a system in which a drive motor is mounted inside a wheel along with a braking device, and the motor inside the wheel directly drives the wheel. An SR motor drive in replace of the conventional PM motor drive for in-wheel motor system has been proposed and analyzed. Two different types of converters were selected and their feasibility in terms of different current control schemes was analyzed and validated through dynamic simulation using PSIM software.
4,000원
24.
2023.12
구독 인증기관 무료, 개인회원 유료
With the mandatory implementation of ESC for trucks starting in 2023, domestic truck manufacturers in South Korea are advocating for a relaxation of the maximum safe slope angle to achieve cost savings. However, there is a lack of research on the dynamic safety of trucks based on ESC installation and the relaxation of the maximum safe slope angle. This study evaluates the relationship between static safety factor (SSF) and the maximum safe slope angle, analyzing the dynamic stability of trucks through simulation considering various experimental variables. The results quantitatively demonstrate the impact of relaxing the maximum safe slope angle on dynamic safety and provide recommendations for future safety regulations.
4,000원
25.
2023.12
구독 인증기관 무료, 개인회원 유료
This study investigates the enhancement of surface precision and dimensional accuracy in STS 316L oval pipes through the application of magnetic abrasive finishing. The experiment involves the modification magnetic pole shapes(A, B, C, D) and a comprehensive analysis of their impact on surface quality. Key parameters include magnetic abrasive KX#320, iron powder, aluminum oxide, light oil, a test specimen rotating at 600rpm, and periodic injection of polishing liquid, a permanent magnet Nd-Fe-B, and magnetic pole steel 1018, reciprocating distance 20mm, and a feed rate 1mm/sec over a 32minutes duration with measurements every 4minutes. The results demonstrate significant variations in surface quality based on magnetic pole shape, with specific configurations demonstrating superior precision and smoothness from the initial surface 0.32μm to 0.06μm.
4,000원
26.
2023.12
구독 인증기관 무료, 개인회원 유료
Power converter devices require a high level of quality because they have a high direct connection with vehicle operation. Therefore, structural bonding was carried out by friction stir welding with excellent mechanical properties. Friction stir welding can cause structural deflection depending on the load of the welding tool, so it is important to control this for high quality flatness. In this study, pre-welding was performed before welding to minimize deflection generated during welding. And deflection reduction data according to the location of pre-welding were analyzed through dynamic analysis. As a result, based on computerized data rather than experimental data an optimized position of pre-welding was secured to minimize the deflection that occurs during friction stir welding. Through this, a process guide that enables high quality structural bonding was presented.
4,000원
27.
2023.12
구독 인증기관 무료, 개인회원 유료
In this study, a numerical analysis study was conducted on the flow characteristics according to the internal flow path change and differential pressure of the hydrogen shut-off valve, and through this, the pressure loss characteristics and flow coefficient of the hydrogen shut-off valve were predicted. ANSYS CFX program was used to predict the flow characteristics of the hydrogen shut-off valve. When the flow path gap was 1.3 mm, the design conditions of the hydrogen shut-off valve were satisfied, and the value of the flow coefficient of the valve was about 1.53. As the inlet pressure of the hydrogen shut-off valve increases, the outlet flow rate increases, but regardless of the inlet pressure, the flow coefficient of the valve is almost constant, ranging from 1.53 to 1.56, indicating that it is the inherent flow coefficient of the designed hydrogen shut-off valve.
4,000원
28.
2023.12
구독 인증기관 무료, 개인회원 유료
This study investigates the utilization of existing CCTV networks for road traffic volume measurement, a key indicator of road infrastructure utility. Traditionally, traffic studies, which are costly and time-consuming, are divided into continuous or ad-hoc surveys. By leveraging current CCTV systems, the proposed method eliminates the need for new installations, conserving resources and increasing efficiency. Preliminary results indicate that this approach offers a time and cost-effective alternative for traffic assessments, with the potential to transform traditional survey techniques.
4,000원
29.
2023.12
구독 인증기관 무료, 개인회원 유료
This study aimed to a sign device using quantum dot film. We synthesized quantum dots with an absolute quantum yield of more than 95% using the solution process method, coated the quantum dot film by mixing it with acrylate resin, made a sign device, and studied the improvement of visibility, and obtained the following conclusions. Quantum dots with absolute quantum yield of 97.63% at 535 nm and 97.85% at 615 nm were synthesized by doping InP with GaP and stacking ZnSe and ZnS composite shells. The synthesized quantum dots were mixed with acrylate syrup at a weight ratio of 10% to coat a film with a luminance uniformity of more than 95%, and the quantum dot film was attached to a luminous display with an insulation capacity of 500 V, an insulation resistance of 99.9 GΩ, and a luminance of 688.5 ㏅/㎠ at white region and 122.3 ㏅/㎠ at red region.
4,000원
30.
2023.12
구독 인증기관 무료, 개인회원 유료
The parking gear is very important part of automotive because it is related to safety. Nonlinear gear groove of parking gear is used to enlarge the contact area between parking gear and pawl. The die has been widely applied for many industrial parts such as machine, automotive and so on. The purpose of this study is to investigate the stability of upper and lower dies by using numerical analysis. As the results, the lower die was weaker than the upper die in this study, and the lower die showed that it should be used within 500ton in terms of safety factor. Further the most weak point of lower die was low location in front of gear. Its minimum value of safety factor was 0.578 in case of 4000ton of press load, therefore, this weak point was needed to be reinforced.
4,000원
31.
2023.12
구독 인증기관 무료, 개인회원 유료
In alignment with South Korea's “3020 Renewable Energy Expansion Plan,” this study focuses on the developing large-scale floating wind turbines. It addresses the challenges of increased size and cost in floating structures for wind turbines over 10MW. This paper details the preliminary design of a novel floating substructure utilizing composite materials(ie, EVA). Structural analysis was performed using ABAQUS, accounting for both typical and extreme wind conditions. Results from the analysis validate that the substructure design is adequately feasible for implementation.
4,000원
32.
2023.12
구독 인증기관 무료, 개인회원 유료
For motor controller designers, building a simulation environment is not a difficult process. After verifying the controller by simulation, it is common to select 20kHz for the current control loop, 1kHz for the speed loop, and 100Hz for the position loop when implementing the actual HW embedded system. This is because maximized cycles (20kHz) for each control loop are unnecessary in control theory and are a waste of cost and HW resources. However, in a simulation environment, each loop will often have the same control cycle (20kHz maximum). This is because we think it is unnecessary to reflect this part in the simulation. In this paper, it is shown that the difference in the sampling time of each control loop makes a big difference in the simulation result, and as a solution, it is proposed to apply LPF to the position loop output stage. In the process, the reasons for the differences were analyzed, and the effect of LPF, the reason for application, and the feasibility of implementation were proved by actual software coding.
4,000원
33.
2023.12
구독 인증기관 무료, 개인회원 유료
The purpose of this study is to develop the protection of passengers in the event of a side collision with a school bus for children. Rub-rail is installed in the United States and other countries to protect the side of school buses for children to some extent. However, in the case of Korea, there are no safety devices to protect the side of school buses for children. Therefore, the FE model was analyzed to see if there is a difference depending on whether or not Rub-rail installed on school buses in the United States is applied, and whether it affects the damage to the human body. As a result, the maximum amount of intrusion at the point of collision differs depending on whether Rub-Rail is installed. It is expected that the evaluation results of IIHS for Rub-Rail may vary depending on the degree of intrusion.
4,000원
34.
2023.12
구독 인증기관 무료, 개인회원 유료
This study developed an IoT-based agricultural well control system and demonstrated it through a control system in the current state of domestic open-field smart farms where systematic management is insufficient due to the difficulty of collecting accurate data such as agricultural water intake and usage. As a result, it was possible to derive the optimal control system test results according to the watering conditions for each schedule by conducting automatic control focusing on periods when there is no precipitation. This means that irrigation can be carried out smoothly during the time when irrigation is needed to improve crop quality and secure farm income, and as a result, it is possible to systematically manage and operate among demonstration farms connected to irrigation, resulting in a shortage of agricultural water and a resolution of supply imbalances.
4,000원
35.
2023.12
구독 인증기관 무료, 개인회원 유료
Titanium constitutes approximately 60% of the weight of steel and exhibits strength comparable to steel's but with a higher strength-to-weight ratio. Titanium alloys possess excellent corrosion resistance due to a thin oxide layer at room temperature; however, their reactivity increases above 600°C, leading to oxidation and nitridation. Welding titanium alloys presents challenges such as porosity issues. Laser welding minimizes the heat-affected zone (HAZ) by emitting high output in a localized area for a short duration. This process forms a narrow and deep HAZ, reducing the deterioration of mechanical properties and decreasing the contact area with oxygen. In this study, fiber laser welding was conducted on 8.0mm thick Ti-6Al-4V alloy using the Bead On Plate (BOP) technique. A total of 25 welding conditions were experimented with to observe bead shapes. The results demonstrated successful penetration within the 0.792mm to 8.000mm range. It was concluded that this experimental approach can predict diverse welding conditions for Ti-6Al-4V alloys of various thicknesses.
4,000원
36.
2023.12
구독 인증기관 무료, 개인회원 유료
Safe operation of freight vehicles is an important issue for drivers, cargo, and other road users. In particular, the center of gravity of a freight vehicle is directly related to the stability of the vehicle, and this can fluctuate in real time depending on weight changes. Every time a freight vehicle loads or unloads cargo, its center of gravity changes, and these changes greatly affect the risk of vehicle rollover. We researched a continuous center of gravity measurement system for freight vehicles for safe driving.
3,000원
37.
2023.12
구독 인증기관 무료, 개인회원 유료
By developing a high-quality plexiglass sign using LED, it is possible to respond to international competitiveness and effectively cope with market expansion measures. The degree of inhalation of the fine dust blown by the air nozzle was tested so that it was not blown into the air. As a result of this test, the acrylic absorption rate was 82%, an increase of 20% from 60% before improvement, and the working environment was improved. With the development of the dust extraction device for the acrylic processing machine in this study, the suction and removal of acrylic fragments or dust is smoothly performed, resulting in a cleaner, more hygienic and improved safety through the improvement of the working environment. As a result of comparing the amount of burr generated in the plexiglass material and comparing the degree of test performance for reaching 24,000 rpm, it reached 24,000rpm.
4,000원
38.
2023.12
구독 인증기관 무료, 개인회원 유료
The electrification of transportation is expected to greatly contribute to achieving the global climate change target. This study analyzed technological competitiveness in the fuel cell electric vehicle (FCEV) field based on patent family and citation index. Technology analysis was conducted by dividing FECV into six sub-technology areas based on IPC with fuel cell system, fuel cell technology, vehicle system, hydrogen storage and fueling, catalyst technology and etc. The largest number of patents are being filed in the fuel cell system technology field, and the fields with high growth rates over the past 10 years (2012-2022) were vehicle systems (12.4%) and hydrogen storage fuel field(11.5%). As of 2021, among global automakers, Toyota ranks the first in patent applications for FECV followed by Hyundai Motors in Korea, followed by Honda and Audi, with an average annual growth rate of 19.8%, the highest among competitors.
4,000원
39.
2023.12
구독 인증기관 무료, 개인회원 유료
Korea's facility horticultural heating costs account for a high proportion. Therefore, it is the most important factor to consider in greenhouse construction. It is important to assess the heating load of greenhouses. But there is not much data from the weather station. This study determined the heating load for each segmented area using the spatial correction method. The heating degeneration calculated from standard weather data (AHDH and BHDH) and total weather data (CHDH and DHDH) is consistent. However, there was a big difference between AHDH and DHDH. Therefore, the updated heating load data for each region is needed. Each of the four types of set temperatures (8℃, 12℃, 16℃, 20℃) was provided, and the heating temperature setpoint (℃) for each region of 168 cities and counties was presented. As a result of the analysis, the reliability of about 99% was confirmed in most of the regions suggested in this study. By using the calculated heating load for each region, it is possible to predict and utilize energy consumption and management costs.
4,600원
40.
2023.12
구독 인증기관 무료, 개인회원 유료
The curb weight of electric trucks is more than 10% higher than that of conventional internal combustion engine trucks due to the motor and battery. For this reason, cargo box developed for small electric trucks is required weight reduction, and cargo door that can reduce weight and maintain strength are being developed. In this paper, we designed the lightweight cargo door, confirmed the stability of the door through structural analysis, and developed a cargo box door that was more than 25% lighter by applying composite materials such as Sheet Molding Compound(SMC) and Fiber Reinforced Plastic(FRP).
4,000원
