AUTOMOTIVE FORMABILITY SIMULATION PROCESS FOR EARLY DESIGN PHASES

EL-SAYED J.,KIM H.,FRUTIGER R.,LIU W. The Korean Society of Automotive Engineers 2005 International journal of automotive technology Vol.6 No.3

Formability simulation of automotive panels at early design phases can reduce product and tooling development time and cost. However, for the simulation to be effective in leading the design process, fast and reliable results should be achieved with limited design definition and minimum modeling effort. In this paper, nonlinear finite element analysis is used to develop an automated process for the formability simulation of automotive body panels at early design phases. Due to the limited design definition at early design phases, the automated simulation process is based on the plane strain analysis for selected number of typical sections along the panel. Therefore, an entire panel can be analyzed with few sections. The state of plane strain can be easily induced, during simulation through symmetry and applied boundary conditions that simplify the modeling process. To study the reliability and effectiveness of the developed simulation process, the analytical results are compared with measured results of production automotive body side panels. The comparison demonstrates that the developed simulation process is reliable and can be effective for analyzing sheet metal formability, in early vehicle development phases.

자동차 차체 패널의 점용접 및 플러그용접 특성에 대한 실험적 분석

권종호(Jongho Kwon),김장훈(Janghoon Kim),이용우(Yongwoo Lee) 한국자동차공학회 2016 한국 자동차공학회논문집 Vol.24 No.6

This paper presents a comparison of an experimental study on spot and plug welding of an automotive body panel. Spot welding is a common joining technology used in automotive body panel assembly. In automotive body repair, however, plug welding is widely used due to its technical simplicity and cost benefit. Some researchers have focused on the use of spot welding in the manufacturing process, but there has been very little research done with respect to the engineering analysis of the plug welding process. In this study, two kinds of specimens are considered to compare the difference of failure strength between spot weld and plug weld: normal tension and shear tension. The experimental results show, in both normal tension and shear tension, that spot welding has higher failure strength than plug welding. In addition, plug welding is more vulnerable to shear tension than normal tension. This study can be applied to further studies on practical optimization for maintenance and repair of automotive body panels.

측정 데이터 이용한 자동차 외판 미세굴곡 추적 사례 연구

정연찬(Yun Chan Chung),이상헌(Sang Heon Lee),장대순(Dae Soon Chang),박상철(Sang Chul Park) (사)한국CDE학회 2013 한국CDE학회 논문집 Vol.18 No.2

This paper proposes an approach to detect unintended deflections in an automotive outer panel. Conventionally, the detection of unintended deflections has been performed by experienced works, and it requires much amount of time and efforts. The motivation of this work is to reduce such efforts by providing an automated detection methodology. For the detection of unintended deflections, we make use of the measured data from an optical scanner which can be considered as a Z-map data. The proposed approach consists of four major steps; 1) measured data acquisition for an automotive outer panel, 2) identification of shape features, 3) removal of shape features, and 4) detection of unintended deflections via curvature analysis.

자동차 외판 특징선의 시각적 분석을 위한 시편 제작방법

한주호(Juho Han),정연찬(Yunchan Chung) 한국생산제조학회 2015 한국생산제조학회지 Vol.24 No.4

A feature line is a visually noticeable creased line on outer automotive panels. Feature lines play an important role in creating a good impression of a car. Even though the manufacturing quality of feature lines is important, it is difficult to achieve the designed shape owing to the springback of sheet metal. The current study presents five methods of making samples that will be used in a visual experiment to discover a quality control quantitative manufacturing allowance for feature lines. Measurement and inspection methods for the samples are also presented. The results show that plunge machining is the most accurate way to make the desired shape, and that wrapping the machined surface with sheet film is an appropriate way to emulate the roughness and visual texture of the painted outer panels of a car.

자동차용 판재의 Subtle Feature의 성형 조건에 따른 곡률 반경 예측 모델에 대한 연구

유제형,정규석,정연찬,이창환 한국정밀공학회 2023 한국정밀공학회지 Vol.40 No.1

The subtle feature is one of the characteristic lines and represents the most noticeable line in the automotive panel. In this study, we proposed a method to predict the radius of curvature of products according to the material, its thickness, its punch angle, and its punch radius. The radius of curvature was divided into three regions, namely, the non-linear, transition, and linear regions. In the non-linear region, the prediction model for the radius of curvature with different forming conditions was derived using the finite element analysis. In the linear region, the radius of curvature was assumed to be the sum of the punch radius and the thickness of the material. In the transition region, a model connecting two regions (Non-linear and linear region) was developed based on the continuity condition. The prediction model presented a very small RMSE with the value of 0.314 mm. Using the prediction model, the radius of curvature with various forming variables could be predicted and the required radius of punch, to obtain a certain value of the radius of curvature, could be precisely predicted.

자동차 외판 특징선의 형상 분석

오아영(A. Y. Oh),이유진(E. G. Yi),이채연(C. Y. Lee),권성오(S. Kwon),박웅(W. Park),정연찬(Y. Chung) 한국소성가공학회 2013 금형가공 심포지엄 Vol.2013 No.9

This paper presents a geometric analysis of section profiles for the evaluation of manufacturing quality of feature lines. A feature line is the geometry which is a visually noticeable creased line on the smooth automotive outer body panel. The quality of the feature line is important because the line is prominent and crosses over other parts. Section profiles of a feature line on a side outer panel are studied. The section profiles of the design part are computed using a CAD tool and the section profiles on a stamping part are measured using a stylus profilometer. This paper proposes geometric entities to compare the section profiles, such as chordal length and height, and fullness. The results for an example show that the chordal height difference is 0.014~0.025mm and the fullness difference is 0.133 ~ 0.207.

Integrated Skin Deco 공법 적용 인스트루먼트 판넬 연구

정선경(Sun kyoung Jeoung),이평찬(Pyoung-Chan Lee),임유석(Yusuk Im),권승용(Seongyong Kwon),김재홍(Jaehong Kim) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

미래 자동차의 메가 트렌드는 고객의 인식 향상 및 요구 증대로 인해 인간 중심의 고감성 통합 인테리어 기술 적용이 확대될 것으로 예상되며 이를 위하여 다양한 분야에 걸친 새로운 시도들이 자동차에 적용될 것으로 예상되어 진다. 이러한 고객의 수요는 자동차에 쓰이는 소재의 감성화, 기능성화를 촉진하며, 웰빙을 위한 Low VOC 및 고감성 소재 등의 사용이 증가할 것으로 예상되어진다. 이 중 Instrument Panel(IP)은 자동차 부품중에서도 운전자와 가장 접촉이 많은 Interior 제품으로 디자인과 감성품질에 크게 작용하고 있다. Instrument Panel의 제조 과정은 skin 성형 공정, 발포 공정, 사출 Deco 부품 조립 공정 등의 많은 제조 공정을 거친다. 본 연구에서의 ISD(Integated Skin Deco)공법은 Deco 부품으로 도장 가공을 하지 않는 Deco Sheet를 동시 성형하여 공정 단순화 및 다양한 형상 구현에 용이하도록 하였다. Deco sheet는 내열성이 뛰어난 PC계 고분자를 적용하였으며, 성형 후 표면 단차를 줄이기 위해, 3~5 mm이하의 소재를 개발?적용하였다. ISD 공법 적용IP의 감성 및 내환경성 평가를 진행하였으며, 부품의 장기내구 신뢰성 평가 결과 내열성능 및 내약품 성능 또한 최고 등급 수준인 4-5등급을 보였다. 또한 차량에 충격이 가해졌을 시 IP에 생길 수 있는 Sharp edge로 인한 운전자 및 동승자의 안전을 위해 국내 법규 항목(KMVSS 88)인 H/Impact 시험을 진행한 결과 외관상 변화가 없어 자동차 인테리어 부품에 적용 가능함을 확인하였다.

차체 패널용 드로우 금형 설계를 위한 CAD 시스템의 개발

이상화(Sang Hwa Lee),황인범(InBeom Hwang),이상헌(Sang Hun Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper describes a dedicated 3-D CAD system based on Unigraphics NX for draw die design for automotive body panels. The system provides 3-D design capabilities based on knowledge base and standard part libraries. To enhance redesign productivity, the design process modeling technique has been introduced. By introducing this system, dies can be designed more rapidly in the 3-D space, and their solid data can be directly transferred to CAM tools for NC tool path generation and simulation tools for virtual manufacturing.

점용접의 해석 모델 개발 및 용접조건에 대한 영향도 분석

방혜진(Hyejin Bang),주용현(Yonghyun Ju),최정훈(Junghoon Choi),신현식(Hyunshik Shin),정병성(Byungsung Jung),박규종(Kyujong Park),이상교(Sang-kyo Lee),조종두(Chongdu Cho) 한국자동차공학회 2015 한국 자동차공학회논문집 Vol.23 No.6

Resistance Spot Welding (RSW) is the method for joining two overlapped base materials when high pressure and current is applied from electrodes. Due to the safety problem such high pressure and voltage, automation should be early adopted. In this paper, the spot welding is developed as a computational model of wheel house from GM Korea and the welding condition such as weld sequence is considered. The computational analysis is preceded as a static and elasto-plastic procedure and used thermal expansion coefficient represents a dependency of spot volume between two panels. In case of welding sequence, the efficiency which depends on the distance between current spot point and the other is calculated in several cases.

The Effects of Exchange Rate Volatility on Korea’s Automotive Industry Exports: A Panel Cointegration Analysis

정문현 한국무역연구원 2016 무역연구 Vol.12 No.4

This paper investigated the impact of exchange rate volatility on the automotive industry exports of Korea using a traditional long-run export demand model. In measuring the exchange rate volatility this study employed the General Autoregressive Conditional Heteroscedasticity [GARCH(1,1)] model and the standard deviation approach. To this end, the panel cointegration analysis was applied to the monthly exports of Korea’s automotive products to 28 major trading partners for the period March 2001 to December 2014. The panel dynamic ordinary least squares (DOLS) and the panel fully modified ordinary squares (FMOLS) estimations were employed to verify the long-run relationships among the regression variables. The empirical results provided evidence that exchange rate volatility has negative effects on the automotive industry exports of Korea. However, such effects were found to have relatively smaller magnitude on the automotive parts exports compared to the motor vehicle product exports. This would seem to suggest that the differential effects of volatility on the magnitude can be due to the influences of production sharing across globe, which tends to weaken the sensitivity of exchange rate uncertainty on intermediate goods trade.