Entity

Time filter

Source Type


Shim J.Y.,Environmental Materials and Components Center | Kim I.S.,Mokpo National University | Lee K.J.,Automotive Components R and D Group | Kang B.Y.,Environmental Materials and Components Center
Metals and Materials International | Year: 2011

Recently, there has been a trend in the automotive industry to focus on the improvement of lightweight materials, such as aluminum and magnesium because the welding of dissimilar metals causes many welding defects. Magnetic pulse welding (MPW), one of the solid state welding technologies, uses electromagnetic force from current discharged through a working coil which develops a repulsive force between the induced currents flowing parallel and in the opposite direction in the tube to be welded. The objective of this paper is to develop a numerical model for analysis of the interaction between the outer pipe and the working coil using a finite element method (FEM) in the MPW process. Four Maxwell equations are solved using a general electromagnetic mechanics computer program, ANSYS/EMAG code. Experiments were also carried out with a W-MPW60 machine manufactured by WELMATE CO., LTD. with the Al1070 and SM45C for Al pipe and steel bar respectively. The calculated and measured results were compared to verify the proposed model. © KIM and Springer. Source


Lee J.W.,Environmental Materials and Components Center | Kim Y.J.,Environmental Materials and Components Center | Kang S.I.,Environmental Materials and Components Center | Kim J.Y.,Seoul National University | Hong D.P.,Chonbuk National University
Applied Mechanics and Materials | Year: 2013

This study was carried out to analyze the dynamic characteristics of the seed plate which is the main part of the vacuum precision planter. The vacuum precision planter is a working machine which is attached to a tractor. The vacuum pump is operated by PTO-shaft which rotates in three types; 540 rpm (9 Hz), 750 rpm(12.5 Hz) and 1,000 rpm(16 Hz). Seeds are sucked into the holes of the seed plate by vacuum, and then they are transported by rotation. At that time, the mode shape of seed plate is important because dynamic characteristics of the seed plate decide seeding rates. If the natural frequency of seed plate corresponds with the frequency of PTO-shaft, the resonance occurs. For this reason, modal analysis of the seed plate was made with FlexPDE(PDE solutions, inc) and ANSYS(ANSYS, inc). Mode shape was observed for 5th mode. First, modal analysis of the seed plate was performed by FlexPDE. According to the result of FlexPDE, natural frequency of each mode was obtained 35.7 Hz, 35.8 Hz, 45.3 Hz, 60.8 Hz and 61.0 Hz respectively. The other modal analysis of the seed plate was performed by ANSYS. As a result of the ANSYS analysis, natural frequency of each mode was obtained 35.6 Hz, 36.0 Hz, 45.6 Hz, 60.9 Hz and 61.1 Hz respectively. The results of the FlexPDE and ANSYS were similar. Natural frequency of the seed plate was confirmed by the above results. So, it was confirmed that the resonance didn't happen by comparing the frequency of PTO-shaft and natural frequency of seed plate. In conclusion, the vacuum precision planter is expected to efficiently sow. © (2013) Trans Tech Publications, Switzerland. Source


Choi Y.,Environmental Materials and Components Center | Kim D.U.,Environmental Materials and Components Center | Kang B.Y.,Environmental Materials and Components Center | Park D.K.,DTS | And 3 more authors.
Journal of Mechanical Science and Technology | Year: 2013

In today's reality, which requires automotive technical development to be environmentally friendly and highly efficient, lightening the weight of the propeller shaft for automobile actuation is also required. Some automobile manufacturers have developed and are applying the propeller shaft for automobile actuators to their production and accomplishing more than 30% reduction in weight by replacing steel materials with high strength aluminum alloy. For the propeller shaft, manufacturing technology of aluminum tube with high stiffness and high precision is required due to the problems of noise and vibration. In this study, the seamless tubes of aluminum alloy 7003 are hot extruded and cold drawn. The forming processes are simulated and modified to reduce and make uniform any plastic deformation. More precious tubes can be obtained by modifications. Extrusion with hollow billet and optimization of drawing tools were introduced for the production of an aluminum tube with high strength and high precision for the propeller shaft. © 2013 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg. Source

Discover hidden collaborations