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Influence of the variation of its geometry on the disk failure
Jongman Kim(김종만),Hyo-Kune Hwang(황효균),Byung-Ju Dan(단병주),Jin Woo Lee(이진우),Wae Yeul Kim(김외열) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4
The speed competition of optical disk drive has been accelerated with the fast advancement of its storage density and data transmission technology. The continuous increase of the spinning speed of CD meets the unexpected and catastrophic failure of disk during the operation. The effect of its thickness and outer radius of disk were investigated to reduce stresses and J-integral around the crack tip. The effect of its thickness was considered ahead of the crack tip. In the effect of outer radius of disk, linear elastic fracture mechanics was used to obtain the critical crack length, which indicates the onset length for unstable crack growth. This approach is so significant as to detect the growing crack by disk drive before the catastrophic failure, which will provide the standard size of its safety for high-speed disk drive.
황효균(Hwang Hyo-Kune),김남웅(Namwoong Kim),단병주(Byung Ju Dan),김종만(Jongman Kim),김외열(Wae Yeul Kim),이진우(Jin Woo Lee) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11
CD-R disc drive is one of the basic options of personal computer today. In this trend, various CD-R discs<br/> can be purchased in every market. Even very low quality discs are in market too. Today's CD-R disc drive is<br/> being operated over 10,000 RPM. So the possibility of the disc fracture is growing faster. Sometimes, during<br/> the test of a new disc drive by various methods to confirm the quality of it, fracture of the disc happens. And it<br/> happens in end user's personal computer scarcely. In this reason, new methods to confirm the quality and the<br/> failure mechanism of the optical disc are studied in this paper.
황효균(Hyo-Kune Hwang),김남웅(Namwoong Kim),단병주(Byung Ju Dan),김종만(Jongman Kim),김외열(Wae Yeul Kim),이진우(Jin Woo Lee) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4
The base material of optical disc is the amorphous polymer, polycarbonate. So crack growth on the rotating optical disc could happen by the static centrifugal force. This phenomenon is called static fatigue. Today's CD-R disc drive is being operated over 10,000 RPM. This is increasing the possibility of the disc fracture when operating. In this reason, new method to measure the static fatigue threshold quality and the way to calculate the threshold J-integral value and the safe crack length of the optical disc are studied. Finally the environmental effect to optical disc is also studied in this paper.
CAE 기법을 이용한 1 DIN Car DVD Receiver의 열설계
류호철(Ho Chul Ryu),김광모(Kwang Mo Kim),박정응(Jung Eung Park),김외열(Wae Yeul Kim),이진우(Jin Woo Lee) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4
In the present work, the practical thermal design process of 1 DIN car DVD receiver described. In the course of its efficient design, CAE technique was essentially used. CAE technique has reduced research period, man power and material cost but has increased research convenience, organized results and persuasive power. CAE technique helped to study parameters such as vent, fan and heat sink. Using these elements, it tried to meet optimal thermal solution. But safety standard, printed circuit board and framework mechanism should be considered as the constraint. To overcome these constraints, we tried to communicate and compromise with projectors in charge. After all, the price of those efforts has made the most competitive heat sink for heat dissipation in the 1 DIN car DVD receiver market. Moreover, we are trying to save $3 per product by removing fan. This paper is supposed to show an example of the CAE technique and help thermal designers to make electronic packaging goods.