Carbon Fiber Reinforced Plastics (CFRP) is an encouraging material for aerospace and automotive industries due to its light weight and high strength. Aerospace parts require precise dimensional tolerance and high machined surface quality for safety and reliability. Routing process is needed to produce satisfactory dimensional accuracy of CFRP parts. Machining defects of routing process are related to the cutting mode with respect to cutting angle and bonding strength between carbon fibers and polymer matrix. When the polymer matrix is transformed from polymer to amorphous state, bonding strength is declined. Therefore, cutting temperature is a critical parameter for CFRP machining process because glass transient temperature is relatively low. In this paper, cutting temperature was measured using thermal imaging camera. Machined surface roughness and maximum fiber pull-out depth were analyzed with respect to feed, spindle speed, and laminate structure.
Citations
Citations to this article as recorded by
A Study on the Improvement of Bonding Strength of Heterojunctions by Applying Laser Surface Treatment to Carbon Fiber Reinforced Plastics Huan Wang, Seong Cheol Woo, Chung-Ki Sim, Seong-Kyun Cheong, Joohan Kim Journal of the Korean Society for Precision Engineering.2022; 39(9): 683. CrossRef
Comparison Study on Side Milling of CFRP with AlCrN-based, Diamond-Like-Carbon(DLC), and Diamond-Coated End Mill Min-Woo Sa Journal of the Korean Society of Manufacturing Process Engineers.2020; 19(4): 9. CrossRef
Fabrication of Micro Tool Electrode by Micro EDM using Wear Ratio In Yong Moona, Do Kwan Chung, Bo Hyun Kim Journal of the Korean Society of Manufacturing Technology Engineers.2018; 27(1): 1. CrossRef
In this paper, topology optimization of a main roller for Multi-wire saws is conducted for the purpose of reducing mass of the main roller. Modal analysis is carried out to evaluate whether the resonance could have occurred, or not. The pressure from the cutting wires are modelled mathematically. Topology optimization analysis with the pressure model developed is conducted to derive optimal solution of the sectional shape of the roller. As a result, the cross section of the main roller manifests as an arch shape. The mass of the final optimal model is reduced by 14%, while the deflection and natural frequencies of the roller is same as those of the base model.
Citations
Citations to this article as recorded by
Research on High-Speed Vibration and Structure Optimization of Multiwire Sawing Machine Zhikui Dong, Ao Liang, Long Chang, Shang Wu, Binfeng Hou Applied Sciences.2023; 13(17): 9889. CrossRef
Optimization Design of Student KSAE BAJA Knuckle Using SLM 3D Printer Young Woo Im, Geon Taek Kim, Hyeon Sang Shin, Kang Min Kim, Bu Hyun Shin, Jong Won Lee, Jinsung Rho Journal of the Korean Society for Precision Engineering.2023; 40(9): 719. CrossRef
Study on the Bearing Arrangement of Multi-wire Saw Equipment Using Spring Elements Hye Ryang Park, Jun Young Lee, Hong Jae Yim, Jay Il Jeong Transactions of the Korean Society for Noise and Vibration Engineering.2019; 29(4): 488. CrossRef
The surface roughness and cutting forces are the important factors for the machine-part quality during the hard-turning process. The aim of this paper is to optimize hard-cutting conditions via implementation of response surface methodology (RSM). The experiments were conducted for the hard-turning process with the Box-Behnken design. The validation of the surface roughness and cutting forces was performed with the obtained 2nd order polynomial regression model. The results showed that the surface roughness was strongly dependent upon the RPM. The diminution of the cutting force was attributed to the low feed rate and the depth of cut. On the basis of the RSM, optimized cutting conditions of RPM, feed rate, and depth of cut are 3440, 0.0352 [mm/rev], and 0.03 [mm]. In this optimal cutting condition, the surface roughness can be around Ra= 0.202 μm.
Three-dimensional (3D) scanning processes have been applied to a wide range of manufacturing industries for inspection and reverse engineering. Especially, optical scanning method is used mostly as a non-contact scanning technique in manufacturing field. However, it can be influenced from surface characteristics such as transparency and reflectivity. To resolve these problems, various coating techniques have been studied for years. Among them, atomization-based coating method is one of the key technologies to change its characteristics before scanning the objects. In this study, atomizationbased spray coating system is developed for producing a uniform thin layer. Then, a series of experiments are conducted to evaluate the coating performance with the developed coating system. As a result, after coating the surface of transparent and shiny target objects: glass slide, colour sample, cell cover, and clutch lever, 3D scanning results show that a uniform coating of target objects is significantly improved. Its coating thickness is less than 1 μm which means that it is important to keep the geometry unchanged of the part.
Computer numerical control (CNC) part programs generated by computer-aided manufacturing software are frequently composed of numerous G01 blocks. CNC interpolator applies acceleration and deceleration to generate velocity profile of each block. Therefore, the machining time is increased when the number of G01 blocks is increased. To reduce the machining time, corner blending has been used to smooth the corner shape of adjacent blocks. Because the tool path generated by corner bending dose not reach the commanded endpoint, error of the interpolated tool path exists. The objective of this study was to present a method to determine block overlap time to limit tool path error generated by corner blending. An algorithm to calculate tool path error with respect to block overlap time was also proposed. Performance of the proposed algorithm to limit tool path error was demonstrated in this study.
Citations
Citations to this article as recorded by
Impact of broad ion beam center alignment and mask position on Si wafer cross-section milling rate Jong-Han Won, Ki-Hwan Kim, Dong-Young Jang, Geon-Yeong Park Micro & Nano Manufacturing.2025;[Epub] CrossRef
Block Overlap Based CNC Interpolator with Variable Time Constant Chan-Young Lee, Chang-Ju Kim, Seung Guk Baek, Segon Heo Journal of the Korean Society for Precision Engineering.2025; 42(2): 169. CrossRef
Process Monitoring and Part Program Optimization Using Virtual Machine Tools Chang-Ju Kim, Segon Heo, Chan-Young Lee, Jung Seok Oh Journal of the Korean Society for Precision Engineering.2022; 39(12): 879. CrossRef
Cycle Time Estimation of Block Overlap Based CNC Chan-Young Lee, Seung-Kook Ro, Chang Kyu Song, Jeong Seok Oh Journal of the Korean Society for Precision Engineering.2022; 39(7): 537. CrossRef
Improved Input Shaping Method for Circular Interpolation of a 2-Axis Positioning System Jin Uk Sim, Pil Kyu Choi, Sun-Woong Kwon, Seong-Wook Hong Journal of the Korean Society for Precision Engineering.2022; 39(4): 283. CrossRef
CNC Algorithms for Precision Machining: State of the Art Review Chan-Young Lee, Seong Hyeon Kim, Tae In Ha, Jaehong Min, Soon-Hong Hwang, Byung-Kwon Min Journal of the Korean Society for Precision Engineering.2018; 35(3): 279. CrossRef
Pressure sensors are widely used in industries, including cars and coolers. Highly accurate pressure sensors are capable of corresponding to changes in the surrounding temperature. Additionally, the manufacturing process of pressure sensors greatly impacts the cost and degree of precision. This study undertook to examine the manufacturing process of pressure sensors, especially those using ceramic diaphragm. Ruthenium oxide (RuO2) was used instead of strain gauge for piezoresistance. TC thermistor (temperature coefficient) resistance compensated for changes in outdoor air temperature. Furthermore, thick-film resistors were precisely adjusted with laser trimming technology. These processes resulted in the production of a high accuracy diaphragm pressure sensor having an ability to correspond to changes in outdoor temperatures.
We describe the design and fabrication of a three-axis force sensor with parallel plate beams (PPBs) for measuring the force of a patient’s thigh in a wearable walking robot. The thigh link three-axis force sensor is composed of Fx force sensor, Fy force sensor, Fz force sensor and a pulley, which detect the x, y and z direction forces, respectively. The threeaxis force sensor was designed using the Finite Element Method (FEM), and manufactured using strain-gages. Experiments to evaluate the characteristics of the three-axis force sensor were carried out. The results of the characteristics experiment indicate that the repeatability error and the non-linearity of the three-axis force sensor was less than 0.04%, and the results for calibration showed that the errors of the sensor was less than 0.1%. Therefore, the fabricated thigh link three-axis force sensor can be used to measure the patient’s thigh force of the wearable walking robot.
Citations
Citations to this article as recorded by
Development of 5-axis Force/Moment Sensor of Gripper to Recognize the Position of an Object within the Gripper Jin Kim, Gab-Soon Kim Journal of the Korean Society for Precision Engineering.2023; 40(5): 415. CrossRef
Development of a 3-Axis Force Sensor for an Intelligent Gripper that Safely Grips Unknown Objects Han-Sol Kim, Gab-Soon Kim Journal of the Korean Society for Precision Engineering.2022; 39(3): 193. CrossRef
Development of Gripping Force Sensor for a Spindle Tool of BT50 Dae-Geon Lee, Gab-Soon Kim JOURNAL OF SENSOR SCIENCE AND TECHNOLOGY.2021; 30(1): 42. CrossRef
Design of Integrated Ankle Torque Sensor and Mechanism for Wearable Walking Aid Robot Han-Sol Kim, Gab-Soon Kim Journal of the Korean Society for Precision Engineering.2020; 37(9): 667. CrossRef
Design and Manufacture of Calf-Link with Knee Joint Torque Sensor for a Tendon-Driven Walking Assistant Robot Jun-Hwan An, Gab Soon Kim Journal of the Korean Society for Precision Engineering.2019; 36(11): 1009. CrossRef
Development of Hip Joint Torque Sensor for Measuring Hip Rotation Force of Walking Assist Robot of Leg Patient Jae-Hoon Park, Gab Soon Kim Journal of the Korean Society for Precision Engineering.2018; 35(8): 753. CrossRef
In this work, a new design for mobiles proposes a flexible display that can be switched between flat and curved surfaces. After a few unsuccessful attempts, a noble conversion scheme between the two configurations was obtained after application of the TRIZ contradiction analysis. For physical embodiment of flat display, effects of design parameters are investigated experimentally using the Taguchi method and response surface methodology. It is suggested that a finite element model might be useful for future applications after proper experimental validation.
Industrial boilers are used in numerous fields, and heat efficiency enhancement is a major topic of study. A double-pipe boiler is a simply structured industrial boiler having a high thermal efficiency. Baffles are specially installed in the doublepipe boiler for increasing the heating time. The baffles determine the heat efficiency of the double-pipe boiler. However, it is theoretically difficult to design a baffle and locate its optimal position, solely by considering the fluid flow of heated air, and the heat exchange between water and heated air. To confirm the correct positioning of baffles, fluid flow and heat transfer simulations were conducted on the boiler. Our results showed that at some points, there was insufficient circulation of heated air. To overcome this problem, baffles were added at these points, by referring to the simulation results. The changing of baffles resulted in an increase in efficiency of heat transfer in the double-pipe boiler.
[Purpose]The purpose of this study was to examine changes in muscle fatigue of the erector spinae, rectus abdominis, quadratus lumborum, and gluteus maximus muscles during repetitive lifting using the squat-to-lift and stoop-to-lift techniques. [Method] Participants were 17 healthy young students in their 20 s. The change in the median frequency of the surface electromyography signal was calculated between baseline and the fatigue trial, where fatigue was self-reported. [Results] A significant decrease in median frequency was identified for the quadratus lumborum and gluteus maximus muscles using the squat-to-lift technique (p < 0.05). [Conclusion] The squat-to-lift technique is associated with fatigue of the quadratus lumborum and gluteus maximus muscles and may not be preferable to the stoop-to-lift technique in all cases.
Citations
Citations to this article as recorded by
Biomechanical Study on the Convenience of Loading and Unloading Laundry in Clothes Dryer Sang Hun Bae, Dong Hyun Kim, Han-Sung Kim, Kyung Chun Kim International Journal of Precision Engineering and Manufacturing.2018; 19(6): 907. CrossRef
ZrO2 film is widely used for high-k applications and also has good mechanical properties. This paper covers the study of the properties of ZrO2 film deposited by atomic layer deposition (ALD) using TEMA Zr and water in the temperature range of 110 to 250oC for potential application in flexible-device fabrication. At a low deposition temperature, ALD ZrO2 films showed a uniform growth rate of ~1 Å per cycle, good uniformity, partial crystallinity, and smooth surface. ZrO2 can also be deposited on the trench structure with a high aspect ratio (~1:50), but conformality needs to be improved for practical applications.
Citations
Citations to this article as recorded by
Suppression of Interfacial Side Reactions and Performance Enhancement of NCA Cathodes via LNO Deposition Using Particle ALD Min-ji Kim, In-suk Song, Hyo-jun Ahn, Sun-min Kim, Young-Beom Kim Journal of the Korean Society for Precision Engineering.2025; 42(10): 851. CrossRef
Methodology for Plasma Diagnosis and Accurate Virtual Measurement Modeling Using Optical Emission Spectroscopy Dongyoun Kim, Seunggyu Na, Hyungjun Kim, Ilgu Yun IEEE Sensors Journal.2023; 23(8): 8867. CrossRef
Analysis of Thermal Reflow Process for Polymer Microlens Fabrication Ji Hoon Lee, Sang Hyuk Yum, Seung Mo Kim Journal of the Korean Society for Precision Engineering.2018; 35(3): 319. CrossRef
First
Prev
