http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
디스크 브레이크 로터의 형상 최적화를 통한 스퀼소음 저감
심현진(Hyunjin Sim),이현영(Hyunyong Lee),조용구(Yonggoo Joe),이정윤(Jungyoun Lee),오재응(Jaeeung Oh) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_2
This paper deals with friction-induced vibration of disc brake system under constact friction coefficient. A linear. finite element model to represent the floating caliper disc brake system is proposed. The complex eigenvalues are used to investigate the dynamic stability and in order to verify simulations which are based on the FEM model. The comparison of experimental and analytical results shows a good agreement and the analysis indicates that mode coupling due to friction force and geometric instability is responsible for disc brake squeal. And the Front brake system reduced the squeal noise using design of experiment method (DOE). This helped to validate the FEM model and establish confidence in the simulation results. Also they may be useful during real disk brake model.
윤태건(Taekun Yun),심현진(Hyunjin Sim),이해진(Haejin Lee),이정윤(Jungyoun Lee),오재응(Jaeeung Oh) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_2
Since human listening is very sensitive to sound, a subjective index of a sound quality is required. Therefore, in the analysis for each situation, the sound evaluation is composed with sound quality factor. Many researchers spends their effort to make a more reliable and more accurate of sound in term of sound quality index for various system noise. In this study a reliable index is constructed and analyzed using correlation analysis, regression analysis and weighting factor for each sound quality factor. We have made the sound quality index that agrees with more than human subjective sensitivity which apply to various sound quality metrics. Also we applied a 'grade' metric to jury for sound evaluation, analyzed relation between sound quality index and sound quality grade. Then we will judge the sound quality level according to the sound quality grade scheme.
Energy Partitioning Approach를 이용한 Solder Joint의 열 피로 수명 예측
오재응(Jaeeung Oh),강원호(Wonho Kang),이해진(Haejin Lee),안영찬(Youngchan Ahn),이정윤(Jungyoun Lee),신승우(Seungwoo Shin) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Thermal fatigue of solder joints is critical to electronic package performance and service life. The electronic package are composed of different materials, thermal stresses generate at near the interface, such as solder joints due to the differences of thermal expansion coefficients. Results of thermal stress-strain occur thermal fatigue fracture at the interface of different materials. The represent study established finite element analysis to determine the stress and strain history in the solder, due to thermal cycling. The computed stress and strain histories are utilized to construct hysteresis plots at each location in the solder joint. The hysteresis plots are then partitioned into elastic strain energy, plastic work and creep work dissipation. The fatigue life of the solder joint is then estimated through an energy partitioning analysis.
단단한 비전도 반평판 사이에서 미끄럼 운동하는 평판층의 열탄성 불안정성
하태원(Taewon Ha),조용구(Yonggoo Joe),김흥섭(Hungsub Kim),이정윤(Jungyoun Lee),오재응(Jaeeung Oh) 한국자동차공학회 2004 한국 자동차공학회논문집 Vol.12 No.1
Frictional healing in brokes causes thermoelastic distortion of the contacting bodies and hence affects the contact pressure distribution. The resulting thermo-mechanical coupling can cause thermoelastic instability (TEI) if the sliding speed is sufficiently high. leading to non-uniform heating called hot spots and low frequency vibration known as hot judder. The vibration of brakes to the known phenomenon of frictionally-excited thermoelastic instability is estimated studying the interface temperature and pressure evolution with time. A simple model has been considered where a layer with half-thickness α slides with speed ?? between two half-planes which are rigid and non-conducting. The advantage of this properlysimple model permits us to deduce analytically the critical conditions for the onset of instability, which is the relation between the critical speed and the growth rate of the interface temperature and pressure. Symmetrical component of pressure and temperature distribution at the layer interfaces can be more unstable than antisymmetrical component. As the thickness α reduces, the system becomes more apt to thermoelastic instability. For perturbations with wave number smaller than the critical ?????? the temperature increases with ?? vice versa for perturbations with wave number larges than ?????? the temperature decreases with ??.<br/>