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EUROSID-2 FE Dummy 를 고려한 유럽 측면 충돌의 해석적 고찰
홍성오(Sung-Oh Hong),홍석길(Seok-Gil Hong) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
EuroNCAP (European New Car Assessment Program) announced recently a modified testing protocol for side impact assessment using the EUROSID-2 dummy instead of the EUROSID-I dummy. The EUROSID-2 dummy is identical in many parts with the EUROSID-I dummy but shows different behavior in experiments. Hence, the<br/> development of a model for the ES-2 dummy is of great interest for the automotive engineers working in the field of safety. EUROSID-2 finite element model has been developed in cooperation with the German Association for Automotive Research(FAT). This paper presents an overview of EUROSID-2 dummy and validation of the first version of FE dummy model for LS-DYNA.<br/>
홍성오(Sung-oh Hong),김홍배(hong-bae Kim) 한국생산제조학회 2007 한국공작기계학회 춘계학술대회논문집 Vol.2007 No.-
Finite element program (ANSYS) estimated thermal deformation quantity in high frequency heat treatment process of a machine too feed drive system slideway and apply deformation quantity in roughing process. Having processed the heat treatment, minimizing methods of the quantity of deformation heat treatment process. 1. Real deformation quantity of slideway and deformation quantity in finite element method difference is a little. it caused by heat lose 2. Having done heat treatment with high frequency after taper processing with considering the existed heat treatment generating the quantity of deformation, existed quantity of deformation can be reduced down to 80%, consequently productivity and material saving can be achieved. 3. When high frequency heat treatment maximum deformation quantity raised almost middle point of length of slideway long or short. The more long length of slideway the large deformation quantity. 4. When high frequency heat treatment at same environment differ from deformation quantity because of long or short length of slideway and difference material properties. 5. When high frequency heat treatment finite element method estimated deformation quantity at difference temperature and time. it is progress at cost down and saved time.
홍성오,김홍배,조규재,Hong, Sung-Oh,Kim, Hong-Bae,Cho, Gyu-Jae 한국기계가공학회 2003 한국기계가공학회지 Vol.2 No.2
Base and saddle feed drive system in machine tool puts in operation for Improvement of life and endure by high frequency heat treatment. In this time, work requirement of establishment to gets by repeat experimentation. In this paper, using the finite elementary method, we predict and revision processing, and gets minimizing of deformation and reduce the progress of Grinding works. Moreover, having high frequency heat treatment, the maximum deformation genesis m the middle parts without slideway length. Take deformation Into finite element program (ANSYS) of taper process in roughing process, after having high frequency heat treatment, existed quantity of deformation can be reduced down to 80 percents.
조규재(Gyu-Jae Cho),홍성오(Sung-Oh Hong),이승철(Seung-Chul Lee) 한국기계가공학회 2008 한국기계가공학회 춘추계학술대회 논문집 Vol.2008 No.-
In order to achieve high precision machine tools. the research for performance enhancement of feed drive systems is required. Development of the high speed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. however, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. One of the important technical issues is how to decrease thermal expansion of ball screw in proportion to the increase of machining speed. When measuring force of stretch of ball screw, since not only actual expansion and the value of bending have to be considered, it is impossible to define the exact value of expansion. In addition, support bearings of ball screw gain considerable force in axial direction. It also generates thermal expansion on the ball screw, and deteriorates the bearings. Thermal expansions of the ball screw in semi-closed loop type NC lathe directly introduces positioning errors along the travel axis. In this paper the thermal displacement of the ball screw is estimated by using macro variables.