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Minimization of Surface Roughness and Machining Deformation in Milling of Al Alloy Thin-Walled Parts
De-Jun Cheng,Feng Xu,Sheng-Hao Xu,Chun-Yan Zhang,Sheng-Wen Zhang,Su-Jin Kim 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.9
This study focused on investigating the surface roughness in the feed direction (R a -Fd), surface roughness in the transversedirection (R a -Td), and thin-walled parts deformation (TWD) during milling of Al alloy 5083. The response surface method(RSM) was used to conduct experiments and establish the models of R a -Fd , R a -Td , and TWD under various cutting parameters. The significance of cutting parameters on R a -Fd , R a -Td , and TWD was analyzed by analysis of variance. It was observedthat the R a -Fd and R a -Td are mainly influenced by the spindle speed, depth of cut, transverse size and feed rate, while the TWD is mainly influenced by the depth of cut. A comparison of RSM-optimum function and artificial bee colony (ABC)algorithm optimum programming was conducted to obtain the best cutting conditions leading to minimum R a -Fd, R a -Td and TWD simultaneously. From the presented results, ABC algorithm was able to obtain the better cutting strategy. Finally, theperformance of the proposed cutting strategy was verified by confirmation experiments.
Friction Experiment of Linear Motion Roller Guide THK SRG25
Cheng, De-Jun,Yang, Wan-Suk,Park, Je-Hong,Park, Tae-Jo,Kim, Su-Jin,Kim, Gyung-Ho,Park, Chun-Hong 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.3
Friction is a characteristic that can be found in machine elements in common engineering use, and it has great effect on the machining performance of a machine tool. Linear motion (LM) guides supported by rolling elements are used for accurate positioning of precision machine. For accurate positioning, the frictional behavior of the LM guide must be understood. In this investigation, a new experiment is conducted to measure friction, and the behavior of LM roller guide friction is measured under various external loads, preloads, velocities, and lubricants. The results obtained from experiment are compared with reference data, and the experimental friction equation of LM roller guide THK SRG25 is achieved from experiment, which can be used to calculate LM roller guide friction and control positioning accuracy.
De-Jun Cheng,Jie Zhang,Zhong-Tai Hu,Sheng-Hao Xu,Xi-Feng Fang 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.10
This paper aims to propose a digital twin-driven (DTD) approach that consists of the machining data (MD) in twin data (TD), design of MD acquisition methodology, construction of intelligent algorithm, real-virtual data interaction analysis and fusion technology, which improvs the predictability and management of on-line quality control of marine diesel engine (MDE) critical parts. Firstly, this paper introduces the theoretical framework of DTD on-line quality control in machining process. Secondly, we construct the process of DTD on-line quality control and introduce the digital twin model of on-line quality control based on TD-driven; the operation of data-driven quality on-line control based on digital twin including description and modeling of MD; acquisition of MD based on digital twin; TD-driven on-line tool life prediction and data fusion on-line machining parameters optimization methods. Finally, a case study is applied to validate the accuracy and availability of the DTD approach. The proposed approach provides a new way for the on-line quality control of MDE critical parts in machining process.
An Aphelinid Species, Aphelinus asychis Walker (Hymenoptera: Aphelinidae) New to Korea
Cheng-De Li,Young-Woong Byeon,Byeong-Ryul Choi 한국응용곤충학회 2007 Journal of Asia-Pacific Entomology Vol.10 No.1
An aphid-attacking parasitoid, Aphelinus asychis Walker, which was reared from Myzus persicae (Sulzer) on Chinese cabbage, is reported for the first time in Korea.
Nonlinear Error Compensation of Complex Surface for Five-axis Machining
Cheng De-rong,Deng Shi-ping,Xing Xiao-Lin 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.12
In order to solve non-linear errors caused by rotational movement of the rotary axis, firstly, it analyzes how non-linear errors are generated in the five-axis machining, and establishes the non-linear error model of complex surface in 3D space. Then it proposes a method of controlling and compensating for nonlinearity errors by introducing the interpolate point based on smoothing tool axis vector. In the method of surface interpolation, it is suggested to add an interpolation point, keep the tool axis vector on sector surface boundary within the start and end tool axis vector of the program block, and maintain the tool axis vector velocity and acceleration continuity. Simulation results show the nonlinearity errors of the fan blade machining are effectively controlled.
Friction Experiment of Linear Motion Roller Guide THK SRG25
De-Jun Cheng,김수진,양완석,박재홍,박태조,김경호,박천홍 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.
Friction is a characteristic that can be found in machine elements in common engineering use, and it has great effect on the machining performance of a machine tool. Linear motion (LM) guides supported by rolling elements are used for accurate positioning of precision machine. For accurate positioning, the frictional behavior of the LM guide must be understood. In this investigation, a new experiment is conducted to measure friction, and the behavior of LM roller guide friction is measured under various external loads, preloads, velocities, and lubricants. The results obtained from experiment are compared with reference data, and the experimental friction equation of LM roller guide THK SRG25 is achieved from experiment, which can be used to calculate LM roller guide friction and control positioning accuracy.
De-Jun Cheng,박제홍,서정세,김수진,박천홍 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3
The temperature distribution in roller Linear motion (LM) rail surface heated with moving frictional heat source was investigated experimentally and numerically. The operating conditions which had not been regarded by previous research, such as the type of the LM guide and operating temperature, were taken into account for improving the previous model of friction force. Frictional heat generation model and heat partitioning coefficient were proposed to calculate the heat transferred to the LM rail. The numerical solutions were calculated in combining a heat conduction equation and the rate of frictional heat flowing into the rail. Frictional heat generation model and heat partitioning coefficient were verified by comparing experimental and numerical results. Simulation results showed that smaller LM block size or higher velocity leads to the higher temperature distribution in the rail surface. Results also indicated that larger motion stroke results in a lower and wider temperature distribution in the rail surface.
Genus Arrhenophagus Aurivillius (Hymenoptera, Encytidae) New to Korea
Li, Cheng-De,Byun, Bong-Kyu 한국응용곤충학회 2001 Insecta Koreana Vol.18 No.4
The genus Arrhenophagus Aurivillius comprising one species, A. chionaspidis Aurivillius is reported for the first time from Korea.